I never had this problem (while prepared PETN many times), but I'm using 65% HNO3 for this method. Try diluted HNO3 to 65%. HNO3 up to some 80% behave as strong oxidation agent, stronger with higher acid percentage.

Blaster,

8 or 9 times and no trouble.It just started about 6 weeks ago.Using the exact same % and methods. I mixed the PE into the hno3 especially slow and stirred 5 min. longer.The h2so4 and hno3/pe already mixed no problem-crytalized OK.The hno3/pe solution OK for about 20 minutes than turns brown quickly(the 1st time looked like it was boiling before I dump-the second time I stirred it alittle with clean rod ,still turned brown).hno3/pe was still in ice bath with h2so4 being mixed.temp was around 10*C after I finished stirring.
It is not the h2so4 -so it has to be either the PE(from same batch) or hno3,The 69-71 % I used during the whole time.Maybe I will try a smaller batch and see what happens.iM SNOWED.

I've made PETN yesterday but I'm not quite happy about the yield.
I used 20ml HNO3 65%, and 15ml H2SO4 93% and 6gr PE.
Mixed the HNO3 and H2SO4 waited 10minutes and stirred and it cooled down to 10*C I poured in PE and it got white, and well added all the PE between 10*C and 15*C stirring for 10minutes after all the PE was in there.
Washed and filtrated it and got 8gr dry PETN.
With those small amounts a lot gets lost in the filter and stuff.
And it are really small crystals so also some got threw the filter.
And is it better to dissolve the PE in HNO3 first or H2SO4?
And in what way do you add it, HNO3+PE to H2SO4 or drip H2SO4 in HNO3+PE?
And how can I test if I've got PETN and not PE anymore?

And how can I test if I've got PETN and not PE anymore?

PETN wont dissolve in water.
PE does - 55 g/l @ (25°C)

And when useing small quantities, as you have, the yield is always somewhat reduced because the loss ratio is far higher. Your yield is OK, using larger quantities you will see an increase in yield.

Read previous page and you will found answers to all your questions.
PE is soluble in water, PETN not.

I did HNO3+PE and wanted to drip that into H2SO4, but the HNO3 oxidized the PE and it made a red plume of NOx...
How can I prevent this? Could I cool down the HNO3+PE mixture, or will it still make a oxidation reaction?
Isn't this the same as where jim2 is talking about?

I the methods given here for making PETN, the time is given as 20-30 minutes of stirring while mixing the PE. What if one keeps the container cool and keeps stirring for hours(with a electric stirrer of course)? I mean I want to know how that will affect the product. In fact this question I'm thinking in a general way. Why there is upper limit of time of strring? As mentioned in this thread that for PETN it's 30 minutes and MAXIMUM 80 minutes.

I doubt that ANY more stirring is necessary AFTER all has dissolved. "Nitric ester formation is nearly infinitely fast if enough HNO3 is present" (from Escales/Stettbacher IIRC).

Thus unless you have a slurry mix, either from an insoluble precursor like starch, or a sulphuric/nitrate mix, you only have to stir until all is dissolved. Or if you use mixed acids for a crystalline precursor like PE or mannitol, where it goes into solution while at the same time a precipitate forms. In this case you do not know the point when all has reacted, so stirring some longer cannot hurt.

In the discussed process, the esterification is completed during the dehydration with SA. THIS is the point where good stirring is mandatory, not only for heat distribution, but also to get a homogenous mix, with no pockets of low-sulphuric, low nitric or high water concentration, which could inhibit complete reaction.

Anyway, keeping the nitric/whatever mix too long before adding SA (or dumping into water in some methods) is not advisable. I had several bad runaways, two even started after the mix was at or below zero degree C, and standing in a –27C freezer! I had planned to cool it down further, then add the SA next morning – bad idea! :p
Those times when I mixed it with SA soon, even +15C did not lead to runaways!

Hey! I was asking about the procedure of Blaster where you chill both NA ans SA and than mix them and then chill the mix again. Then you add PE in very small portion. And moreover I wasn't curious about stirring, thats manadetory anyway(to be on the SAFE side :)) . What I want to know is WHY there is upper limit on time of reaction in case of nitroesters(specially the process mentioned above) and what can happen if the mix is allowed to react longer(while in ice bath of course)
thanks

I know ETN is castable but I found no information whether PETN is castable. While I managed to melt very small amounts, it needed delicate management of temperature, as the PETN quickly starded decomposing into NOx. I did not try to melt any amounts above a half of a gram. Did anyone try this? It could be useful as higher densities could be achieved without pressing.

PETN is my favourite explosive ... cheap ! safe ! POWERFUL !
I make it by nitrating every 10grams of PE with 25ml of H2SO4 and 35ml of HNO3 65%...
here is my video of detonating 40grams of PETN and 60grams of KClO3/petrol mixture
http://members.lycos.co.uk/piropiotr/adam/hx_pl2.mov :)

LOL...That's gotta be the funniest laugh that I've ever heard after a successful test. Did you bust a nut too? :D

That wasn't me laughing :D I don't have a digital camera and that was my friend laughing. He didn't want to lend me his camera so he was with me...

the link : http://members.lycos.co.uk/piropiotr/adam/hx_pl2.mov

Sorry for a bit off topic question, has anyone of you ever tested the shock sensitivity of PETN (I think Urbanski says 45cm/1kg), but i don't know if that is true in practise. So what would you need in a say 1,5kg shell, that would fall on the earth from a hight greater than 1m ,detonated alone by the shock imparted on petn by an impact trigger, and the PETN would than initiate another explosive like say ANNM (or would you need a primary to detonate PETN and PETN would than detonate the ANNM)? I hope you get my question.

Sorry again if this is a bit off topic.

Frank,

Did you solve the problem you had with the PE/hno3 mix turning brown?Blaster suggested that I dilute the hno3 alittle.What did you find

Jim2

jim2: Last time I made PETN from 50g PE batch with 65% HNO3. PE was completely dissolved in HNO3 first, then added in small portions to H2SO4, maintaining mixture temp below 20-25degC. No problem. But, both acids was initially chilled below 5degC and PE/HNO3 was kept at this temp all the time. I think this is essential, because small amount of this mixture remained in beaker and after some 30-60 minutes at normal temp, it turned a bit browny, also in beaker was some fumes visible (oxidation started).
So, if you want to dilute PE in HNO3 first (I think it's more comfortable), use no more concentrated than 65% HNO3, keep PE/HNO3 mixture below 5degC and use it imediately.
Anymore, if you are in doubt, mix both acids first and add PE alone. But intensive stirring is required and watch out possible hot spots!

Excuse me ; may I ask about what's the practical proportions of materials to improvise high explosive such as PETN and CL-20 ? thanks.

And I'm a a new hand to improvise high explosive ,such as PETN and CL-20 .

Althouth so many experts in this web have posted lots of writings about high explosive ,I still hope to find the practical proportion of materials to save the materials .

Sorry to disturb each experts in this web , and thanks everybody again.

Perhaps start with say, 1 mole of Pentaerythitol and 4 moles of Nitric Acid. Not a bad place to start if you ask me. The yield will be abysmal, but if you can't even figure out a ratio, you shouldn't be experimenting with anything much less high energy materials. I'd recomend reading the first 20 pages of this thread, and chances are you'll find a ratio or two.

In my dreams,the last few times I tried using 20 grams PE and things are working out OK again. I now believe that I was not stirring the pe/hno3 mix long enough.I now stir 30-35 minutes and the last several batches have been OK.

AS you said I now put both acids ( separtately) in the freezer for at least 2 hours before using the ice bath.After the mixing of the pe the temp is anywhere up to 10* C.

I do have another question though: In the batches that nox'ed before the pe/hno3 was completely mixed with the h2so4, I am not sure about.Is it Petn? Is it as powerful as the normal stuff?

It has all he charactaristics: the feel,does not dissolve in water---- have not tested to see if it dissolves in acteline.

Perhaps start with say, 1 mole of Pentaerythitol and 4 moles of Nitric Acid. Not a bad place to start if you ask me. The yield will be abysmal, but if you can't even figure out a ratio, you shouldn't be experimenting with anything much less high energy materials. I'd recomend reading the first 20 pages of this thread, and chances are you'll find a ratio or two.

Thank you very much , Mumble . :)
But I asked to several chemical stores about Pentaerythitol , and no one offer Pentaerythitol .
So , maybe I have to compound the Pentaerythitol myself .

Thanks again , Mumble . :)

Jesterday, I tried the way to cool the reaction with dry ice/glycol mix.
Before I added the PE the temperatur of the acids were around -30°C.
I've added 10g PE at once. The temp. rised to -10°C.
I shaked an stired. At least I let it stand for 20min, dumped it in cold water and filtered.
The yield of 10g PE was about 8g PETN.
Don't cool your reaction so extremly!
You will get a very low yield :(

A normal salt/ice bath is cool enough and you will get a much better yield:)

I should talk about my experience.

I synthesized the PETN on last weekend .

It's my first time to make PETN .

I made two samples with different temperatures to compare their

persontage of yields.

Because of reading lots of articles with different temperatures of nitration to synthetize PETN , I didn't know which will be the standard that I had to follow.

One of the two samples was placed outside the ice-bath after addition of HNO3 .

Although this sample has once be placed in ice-bath and be maintained
under 10 degree Celsius , its temperature started to rise .

And I wasn't conscious of its peculiar,I was preparing the second

sample.

When I called to mind the first sample , its temperature became out

of control even I put it into ice-bath again.

Then it fumed lots of NO2 and splashed acid out ; so this sample was
gone because of temperature controless.

And the other sample with temperature control reacted successfully .

So I recommend that the temperature of reaction should be controled
under 10 degree Celsius.

Thanks,everybody.

Ive made PETN twice and I used an salt-ice-bath that cooled the HNO3/H2SO4 mixture to 1°C. (I used 61,1g 65% HNO3 and 55,2g 96% H2SO4). While I added 12,5g of PE the temperature was held between 3-6°C. I added the PE in 0,5g portions. After all the PE was added the mixture was allowed to react for further 30min. Finally I got out 28g of PETN. Not bad :-) !

I have read a few people on here have made homemade detcord and I have a question. I wanted to use 1/4" ID vinyl tubing and fill it with PETN. Is it so important to press the PETN into the tubing? I can't see how that could be done with pieces over a few feet long. Also, I use detonators that are a bit larger then this. Should I just make a smaller one of rolled paper tube? Or a det taped outside the tube is plenty?

Have a look at this webpage http://www.truetex.com/visco.htm it has pictures and a link to a description of a very simple homemade visco-type fuse making machine. If PETN is used instead of BP than one gets a type of simple homemade detcord.

I was going to hold onto this tidbit of genius untill I had the time and equipment to (dis)prove the feasability. I also wanted to have the optimum ratios all figured out, but it looks like I won't have the time to test it for quite some time so heres my idea:

Equipment, Apparatii, and Consumables required:
Secondary high explosive
Poly-urethane expanding wood glue(ie; gorilla glue.
hereafter refered to as PUG)
Aquarium tubing
Empty caulking tube and gun or improvised equivalent

Theoretical procedure:
Mass your HE, calculate 10-20% of that and mass the according number of PUG(to clarify .2*grams of HE==grams of PUG). Add water to the PUG and mix it around for a while until it starts to expand and stops absorbing water, drain any excess water and then mix in the HE. Then place the slurry in the caulking tube and put that in the gun, situate the nozzle in the aquarium tubing. Empty the contents of the caulking gun into the tubing, be sure to cover the opposite end before hand. After the caulking gun is empty remove it from the tubing and thoroughly plug the end . Leave this over night so the glue can fully cure and then it should be ready for use.

Theory behind this
(so you can correct any unforseen/overlooked errors of mine)
Poly-urethane glue reacts with water causing it to cure, normally it is absorbed from the atmosphere but since this will be encased in water proof tubing you need to add the water beforehand. This also allows us to use freshly synthesised HEs(read: just filtered, still wet) since the water will be sucked out by the glue as it cures. Because The glue expands as it cures we can alter the explosive distribution and density of the finished detcord by varying the volume of the tube in relation to the volume of the mixed slurry. The glue expands 3-4 times its original voume(according to my gorilla glue bottle) this also means we need to be sure the ends stay plugged while the glue cures.

Well I hope this solution works since all of this is just my musings and has no experimental data to back it up. Whoever under takes this process would also want to find the optimum OB of their chosen HE with the poly-urethane before wasting valuable chemicals on large batches.

Jesterday, I tried the way to cool the reaction with dry ice/glycol mix.
Before I added the PE the temperatur of the acids were around -30°C.
I've added 10g PE at once. The temp. rised to -10°C.
I shaked an stired. At least I let it stand for 20min, dumped it in cold water and filtered.
The yield of 10g PE was about 8g PETN.
Don't cool your reaction so extremly!
You will get a very low yield :(

A normal salt/ice bath is cool enough and you will get a much better yield:)

I have a most difficult time maintaining low temp (-10C) on my stirring plate as I am limited in size of the bath container. So my experience has been below 20C following the HNO3/H2SO4 common method (Urbanski). I had great yields as well. But I wonder if there is any true advantage to the use of the above Glycol technique.....could the additions take place at a faster rate w/ no run-aways? And if so would this allow for a more consistent nitration?
Let's say that a coil-cooling apparatus (from a refrigeration-system) was used and we could go UNDER 0 C...what would be the advantage during the addition portion of nitration with this or any similar nitrification?

I saw that you were discussing how to plastic PETN so i am writing about my experiences:

I used polyisobutylene to make PETN into plastic and it works nice. I haven't tested it yet how it performs in extreme conditions ( very hot, very cold ), but only on room temp and it works nice.

Polyisobutylene is sold as rodent glue ( for capturing rats and mice ) in our country and it costs max. 2€ per tube. It calls "BIOTOLL" and it has no smell or taste and most of all it is not toxic.

here is the link to description and picture:

http://www.unichemh.hu/biotoll3a.htm

Don't know why it says that it is polybutene, it says 100% polyisobutylene on the tube, but i guess it is the same thing.

PS. sorry for my English --> still learning.

That's nice and convenient- Beats the hell out of dissolving electrical tape in camping fuel!

Today I made some PETN, the yield was about 93% or something like that, but I have a problem:

I have made a saturated solution in acetone, added sodium bicarbonate and left it like that for a couple of hours. Now the solution has got a nasty, urine-like yellow color. I haven't seen anything like that before in my PETN manufacturing. I didn't have any problems with my PETN before.

I use 65% HNO3 and 95% H2SO4. Both are highly pure. And 98% Pentaerythritol, the best I could get, and the cheapest.

Should I recrystallize the PETN in water, or should I throw it away and make a new one? Or is that yellow color just some sodium salt ( sulfate, nitrate )?

PS. about 99% of PETN dissolved in acetone, the rest of it were impurities.

I've got first post jitters.
Today I made some PETN with the H2SO4 + KNO3 method.

First I dissolved 50 grams of pentaerythritol in 500 ml of 93% H2SO4. Then I cooled it to 0 degrees c. To this I slowly added 200 grams of KNO3 keeping the temp down. I left it to react for about a half hour (I think that I should have longer). At the end of the half hour I diluted it in about 2 liters of cold water. It was filtered a few hours later.

It's not purified and weighs about 63 grams.

How could I increase my yield without using nitric acid?

++++++++++

You could read more threads that already exist on this subject.

UTFSE and you'll find them. ;)

NBK

For the members discussing the plasticization of PETN this may be quite relevant and interesting.

It's quite possible that many of you have already come across this patent, but for the ones who have not, it's certainly worth a read.

United States Patent 4047990

The patent is based on creating a plastic explosive with greater stability in extreme conditions of temperature, which doesn't crack or shrink. The binder they experiment with is a Dow Corning silicone.

The explosive they base their findings on, in the patent, is HMX and RDX. However I still thought this would be relevant to this thread as there is no reason to suggest why other explosives such as PETN can't be used.

I've done some searching into which exact silicone it could be (Dow Corning have ALOT of different type silicones available), and have came to the conclusion that the specific type they mention is the "Sylgard 184 two part silicone".

See what you guys think. It was the only product I could find which pretty much matched the patent's given characteristics.

www.dowcorning.com

Their site has information on all their products.

There is a difference between various Dow Corning silicone(s) products. There is something called silicone oil and this is what I believe what they may mean. Often people think of the caulking when they think of silicone.

Please see my post (in the OTC thread) on Ricinoate esters [which] on the other hand are much easier produced. I tried the methyl and ethyl esters by transesterification reaction (Vogel) of castor oil and methanol/ethanol under reflux. The methyl/ethylricinoate seperates as an oily layer at the top. This may be the reference in the patent dealing with binder; plastifier: tackifier (PIB or similar)

I read your post in the OTC thread and found it quite interesting.

I understand your point on the difference between caulking and silicone oil, but in the patent it definitely states a "Sylgard" type product consisting of two parts. One part is the Silicone resin/oil, and the other is a polymethylsiloxane curing agent.

The "Sylgard 184 Elastomer kit" I searched was definitely a close match to this and not just an average caulking, which usually tend to set just from exposure to air.

Reading through the product sheets, I've learned that this particular silicone is actually used for protection in electrical devices and circuits.

I have found a supplier in the UK through Dow Corning's website, so I am interested in looking into this possible binder further. Of course there is a chance it's the wrong product, however, if I can obtain some for a reasonable price I can at least experiment and see what results I end up with.

I’ll be looking to buy some soon, so if I come up with any successful results I'll share them on here. It could be a while until I go ahead and test it, as I still need to synthesize some RDX.

I can tell you with reasonable surety that the silicone oil is something you may really want to buy IF you can find it at reasonable prices. There are some patents that definitively use silicone oil as a plastifier. The tackifier is available via "bird repellent", "rodent glue", etc. This is Polybutene. I advise not to waste your time with PIB from finalized sources. Forming the needed tacky-ness while in situ is more appropriate.

Polybutene is a viscous, non-drying, liquid polymer, which results from the copolymerization of 1- and 2-butene with a small quantity of isobutylene. Polybutene is colorless, has little or no odor, is chemically stable and resists oxidation by light and moderate heat.

An important characteristic in adhesive applications is polybutene’s tackiness, which increases with increased molecular weight. Polybutene acts as both a tackifier and plasticizer and is used to extend the viscosity range and to control the tack and cohesive strength level of adhesives. Polybutene is sold in a wide variety of molecular weights and the viscosity grades range from light oils to highly viscous fluids.

So why the silicone oil? I believe (as I am not a polymer chemist) what it does is control the level of tacky-ness in the end product. I have examined someone's final product of energetic plastic and compared that to an existing example of a commercial product and could barely tell the difference! The above process really works and the energetic plastic is quite utilitarian. It sticks when it needs to stick, stays together and is mold-able. It preforms just like the real deal!

Does polybutene make a better plastique than SBR? Or does the form of the explosive (crystalline/cubic/amorphous/etc) determine which plasticizer is better?

I can only offer an opinion based on what I have seen personally and played with. IMO ---yes.

You have total control over the viscosity and the "feel" of the end product. You have more control in general. We know that if you are using mostly PETN you can go to about 30% inerts. That's damn high but it will still shoot & shoot at the same speed as if it were 18% (which is supposed to be ideal).

But let's say you want to stretch the amount of energetic......Polybutene is still the way to go. This is a highly subjective thing though. Some people believe that the original formula of RDX/PETN percentages is the only way to go due to final performance. There is no argument as it will shoot faster. But to get straight PETN (or some ETN and a % of energetic nitrates) to actually cut concrete is (in IMO) primo.

I'm an old guy and haven't "blasted around" for many a year now but I have seen some sweet goodies made from OTC products!

"Or does the form of the explosive (crystalline/cubic/amorphous/etc) determine which plasticizer is better?"

From my limited experience: The crystal shape, size and *size distribution* does not determine whether a given binder/plasticiser mix is usefull, but it definitely governs how much is needed to get a pliable product that does not crumble apart.

You will need a specific mixture of different size crystals to get by with just 9% binder (aka C-4). In my tests it was hardly possible to go below 25-30%, untill a mix of differently recrystallised RDX was used (precipitated by cooling a hot saturated solution versa crashing in water). Unfortunately the tests were not continued to find the ideal size distribution. Having police in your flat greatly dampens your enthusiasm of having plastique explosives in the fridge. :p

In contrast, Semtex made from surplus/recycled RDX/PETN (hence the varying percentages) is not so carefully designed, and has 30% inerts. Some quotes from Jerry (aka Gerald Hurst, think kinepack + astrolite (co)inventor) at a.e.e. from back when there was intelligent discussion:


From:- "Analysis of Semtex Explosives" J.R.Hobbs.
Chapter 39. p.409-428 in " Advances in Analysis and
Detection of Explosives" edited by Jehuda Yinon
Kluwer Academic Publishers ISBN 0-7923-2138-3 (1993)

Table 1. Summary of Semtex Analysis

Name Semtex H Semtex A
% PETN 49.8 94.3
% RDX 50.2 5.7
Dye Sudan I Sudan IV
Antioxidant N-phenyl-2- N--phenyl-2-
naphthalamine naphthalamine
Plasticizer n-octyl phthalate n-octyl phthalate
butyl citrate butyl citrate
Binder styrene-butadiene styrene-butadiene
rubber rubber

Table 2. Gravimentric Analysis
Sample size 1.0194 1.1061
Weight oil 0.0811 0.0994
% oil by weight 7.9 9.0
weight rubber 0.0920 0.1036
% rubber by weight 9.0 9.4
weight explosives 0.7029 0.7029
[ rest of table omitted ]

The following is a very speculative
theory which attempts to explain the apparent existence
numerous types of "Semtex."

RDX is somewhat less sensitive than PETN. This is an advantage to the military because it means the former can better resist impact initiation in battle. Properly formulated plastic explosives such as C-4 contain as high
a percentage of RDX as can be crammed in without losing the limited coherency of the material, which is a stiff, claylike mass.

Despite the high explosives content of C-4, it is difficult to initiate the material with a #6 blasting cap and failures also sometimes occur with commercial #8 caps when they are not properly positioned in the charge.

Now look at the closest commercial equivalent of C-4, Detasheet, manufactured by du Pont. Detasheet is based on plasticized PETN and is designed to be a cuttable sheet material with a rubbery consistency which holds its dimensions under reasonable abuse. The physical stability of detasheet makes it well adapted for such applications as metal cladding and plane wave generators. Because of the higher sensitivity of the PETN, detasheet tolerates relatively high concentrations of rubberizing ingredients.

If we look at the availability of explosives world-wide from the perspective of an entrepeuner, we see that he can always purchase PETN on the open market. RDX, on the other hand, is only available at a reasonable cost on those relatively rare occasions when some government is selling off surplus stocks.

So, Mr. Entrepeneur formulates his plastique in the cheapest way possible using PETN and all the passive materials he can put in without losing cap sensitivity. He is not at all concerned about the strength of his product as long as it shoots.

Time passes and our businessman gets his hands on some price competitive RDX. His first new batch of "Semtex" is a dud, it won't shoot. He could raise the concentration of RDX up to 91 percent to make "Semtex C-4", but that would raise his costs significantly. Then he finds a happy compromise. He blends in enough PETN to allow the retention of cap-sensitivity at higher inert dilutions.

Batches containing about 50/50 PETN/RDX can tolerate a hefty 30 percent or so of inerts while material with 95 percent PETN handle a whopping 35 percent, and so on.

Without a rather sophisticated laboratory, your average terrorist is unlikely to be able to tell 50/50 from 95/10, but he can estimate the total explosive content by noting a couple of solubilities (acetone and ligroin), so our vendor puts labels on the material: "H" for "hardly detonable" and "A" for "Awfully adulterated." This act of honesty helps assure the manufacturer that he won't receive any "returns" from his customers.

If comrade Vladimir gets Col Khadaffi's order for a few tons of plastique, and Vlad finds he is out of PETN from the Chernobyl plant, does he apologize and not fill the order because he doesn't have the "minimum" 21 percent PETN? Or does he simply manufacture "Semtex U," short for USA, a material remarkably like C-4?

As long as these guys can get their hands on either PETN or RDX individually or in a mixed ordnance scrap pile, they will
continue to manufacture "Semtex" and people will continue to ask "What is the composition of Semtex?" I would be
willing to bet that there is plastique "Semtex" out there adulterated with TNT, HMX (They should be so lucky) and tetryl
as well and probably a good bit of it cut with inerts to the cap-sensitivity limit..

According to your gravimetric analysis table II, the total explosive contents of Semtex "A1" and "H" respectively are 64 and 69%. The corresponding oil/rubber contents are 17 and 18% for totals of about 81 and 87%. Based on the ratios in table 1, the RDX would be 5.7*.64 = 3.6 percent which is far less than the material not accounted for.

That could just be an elitist snobbery on his part.

Ask the people of Pan Am flight 103 if Semtex was crap.

I think Semtex has killed more people than C-4, just like the AK-47 has killed more people than the M-16.

May not be 'perfect', but it gets the job done cheap. :)

why cant you just stick to the subject matter petn/rdx. your American pride-a virus actually is affecting your behavior. M16 has provoked more people in the world than the Ak-47.Bush ordered nukes to flown across your country endangering the whole world. If it were china or N korea, you guys would be singing terrorist. What a shame!

Jujukemist = Food for the Beast?

Flying warheads across the US happened every day for decades on end during the cold war. USAF fucking DROPPED several of them accidentally during that time too, both inside the US and elsewhere- Hard enough for the implosion charges to detonate. Many instances of aircraft fires and detonation of the conventional explosive components are recorded as well. The safeties worked every time, no nuclear explosions resulted. Nasty clean up after, though.

M16 has provoked more people in the world than the Ak-47.

Ohhhhh, I know! M16 jumped off the kitchen table and said to me just this morning; "you are slave master of whole world: you imperialist capitalist pig!"....I was so provoked I couldn't concentrate.


________________

When discussing plastics it's very significant to realize that shaved grades of crystalline particulate were used in many products. But particulate size has a greater impact on SBR. Polybutene is more forgiving in terms of crystal size, shape and consistency. The reason is the controllability of it's viscosity. SBR doesn't do well with needles and it does need some material well below the 400 mesh size to even begin to maintain consistency.

What's more SBR seems to make a block that takes a great deal of time to warm up to to able to mold and form. The Polybutene based materials stay pretty soft, even in temp going down to 20F......just a thought.

Today I made PETN. Here are the results:

20 grams of pentaerythritol were dissolved in 120 ml of 98% sulfuric acid at 40 degrees celsius. In a separate container 200 grams of potassium nitrate were dissolved in 120 ml of 98% sulfuric acid and cooled to about 25 degrees.

The sulfuric/kno3 slush was added to the sulfuric/pentaerythritol over the course of 30 minutes. This was allowed to react for 20 min after the last of it was added.

This was then dumped into 500 ml of cool .water. The yield (after recrystalization) was 36 grams or a 78% yield. Not bad methinks for not using nitric :).

A 2.5 gram shaped charge destroyed the padlock that it was on top of and made a deafening noise.

20 grams of pentaerythritol were dissolved in 120 ml of 98% sulfuric acid at 40 degrees celsius. In a separate container 200 grams of potassium nitrate were dissolved in 120 ml of 98% sulfuric acid and cooled to about 25 degrees.

The sulfuric/kno3 slush was added to the sulfuric/pentaerythritol over the course of 30 minutes. This was allowed to react for 20 min after the last of it was added.

This was then dumped into 500 ml of cool .water. The yield (after recrystalization) was 36 grams or a 78% yield. Not bad methinks for not using nitric :).


Hi folks. I made some PETN the same way as described above (although I only ended up with 30 grams). Next time I make it, would it be allright if I used say 200ml of H2SO4 instead of 120ml in the KNO3/H2SO4 mixture? If using so little H2SO4 is for economical reasons than I'd like to use more if using more isn't gonna give me any problems.

Also, I use Liquid Fire drain cleaner as my H2SO4 source. I tried concentrating it by heating it to about 120C for half an hour but afterwards the volume was still the same and so was the weight. Am I suppose to heat it way higher than water's boiling point because of H2SO4's ability to hold on to water? If so, how high are we talking about? (Until white fumes appear. NBK)

Your help would be appreciated.

gnitseretni - Perhaps a quick look at the wiki article on sulphuric acid? That tells you it boils at 338ºC. So, as NBK said, crank it till white fumes appear, or don't exceed 300(ish)ºC. Fairly common sense.

Also, there is a point where more H2SO4 will be detrimental. If you are familiar with basic collision theory, then it is obvious. If not.... here is a (really) rough run down.

For stuff to react, there are 3 main requirements that need to be fulfilled.

1. Activation Energy - The molecules need to have enough energy to overcome the activation energy. This is often demonstrated when you heat things and they react faster. More kinetic energy means more successful collisions per unit time.

2. Concentration/pressure - If the molecules don't "hit" each other, they don't react. Hence, by increasing the concentration or pressure, you increase the number of possible collisions per unit time. This is particularly important in your question above. If you increase the amount of H2SO4, you may certainly absorb more water, but the molecules of Penta Erythritol and Nitronium ions will collide less. Hence, it is a trade off. Only experimentation will tell you where the optimum point is.

3. Active Site - Not really worth mentioning in this case, but the molecules need to collide in a certain way sometimes to react. More important in things like proteins.

So there, a basic run down on collision theory. If you want to know more (which you do), go find a Year 11/12 chemistry text book for the basics, and work your way up. Otherwise, there are plenty of web pages you can read.

Mostly when I need a moldable explosive I make an Aspirin bottle full of AP putty.
Use
But when I need something stronger I use PETN putty. The process is very similar to the one of AP putty.
Paragraph
You dissolve around 150 grams of double base flake gunpowder in unleaded gasoline. When it's like jelly or maybe abit thicker you add your PETN which should be around 250 grams, stir the hole shit and then add some flame paste (the crap I use to heat my Fondue). Mold it to form, stick fuse in and wait to dry.
breaks

If I'm not mistaken, Dioctyl Sebacate is a derivitive of Lanolin, whuch comes from the sebaceous (oil) glands of sheep and is extracted from wool during processing. It is used in a lot of soaps and lotions and so forth, and should be pretty easy and cheap to get. So I'm thinking Lanolin & Bee'swax, or maybe just parrifin, heated and intimately mixed, might be just what the doctor ordered.

If I were making premolded shaped charges, I would want something rigid-setting to keep up the VOD. I'm thinking PVC, provided Methylene Chloride or MEK won't attack or otherwise interfere with the PETN.

Also, somewhere in this thread somebody mentioned "casting resin" from a fiberglass supply shop. This is usually Polyester, catalyzed with MEKP, and toughened with Cobalt/Copper naphthanate (mixed into the resin individually, of course). So any experimentation with this stuff and ANY explosive should be performed with extreme caution and in very small amounts. Also, the reaction is somewhat exothermic, so that's something else to look out for.

The Sebacate used is synthetic and, in fact is VERY difficult to find in an OTC arena. There is a decided purpose in the polybutene/sebacate dynamic that is a tackifier and plasticizer arraignment for making the crushed needle crystal PETN into a viable & mold-able entity.

Naphthanates would be wonderful to find on the OTC market. If anyone could find any source on that, it would be a serious boon. Many people have sought out sebicates via OTC and came up with nothing.

Any plastics/fiberglass shop should have Copper Naphthanate in diluted form as a toughener/promotor for Polyester and some Vinylester resin systems. You used to be able to get concentrated Cobalt Naphthanate OTC when it was being ued for the same thing (worked better, in fact). But back in the late '60s/early '70s someone used a quart of each to take out the Bank of America branch on Telegraph Avenue in Berkely, CA.

Mixed 50/50 with MEKP it goes off unpredictably and with a great deal of power. And when they mix, you'd better run; a quart of each can turn your driveway into a swimming pool if you bury it a few feet. In my early days in the Aerospace Composites biz. new lab techs were welcomed aboard by mixing a couple of grams of each in a paper cup and sneaking it under his or her stool. After maybe a minute, the stuff would go off all at once, a little on the "thud" side of an M-80. Everyone not in on the joke would shit their shorts, and the poor tech would go home reeking of "Eu de Prank." I'm not sure what the reaction products are, but the smell is on par with Butyric Acid, which has a stench to rival the sickest, most rancid Tyrannosaurus diarreah one could possibly imagine.

One other source for Copper Naphthanate is a product made, or at least marketed by, Jasco. It can be found in lumber and paint stores, and probably Home Depot et al. I've seen it in quart and half-gallon cans. It's got a blue-green tint, as one might expect, and is used as a wood preservative (those greenish-tinted 4x4 fenceposts are treated with it), and it's frequently used for treatment of black mold contamination.

And I'll be damned if I can remember the exact name of the stuff!

It's called "Jasco TERMIN-8"
The product also has the highest level of Copper Naphthenate of any product available.
http://www.homaxproducts.com/products/other/09/faqs.html

I'll have to grab a can & see if the stuff can be extracted with a sensible degree of effort. Could shape up into some sort of binary system.

As for plasticizing PETN, everybody seems to be gravitating toward elastomeric systems. But it occurs to me that a Polyester system, uncatalyzed, would work just fine. Hell, Bondo would probably work great. And if it gets too stiff, a small amount of Mineral Oil should take care of that problem, plus a couple of others.

For one thing, the stuff is designed to have a lot of tack, so it'll stick to auto body panels. This may be a little too much "cling" for ease of handling. Also, the oil will help shield the monomer from atmospheric Oxygen, preventing it from polymerizing during long term storage.

One thing about Bondo, though (or any Polyester system, for that matter). It absolutely connot be used for plasticizing any Peroxide explosive (AP, MEKP, HMTD etc). It is normally catalyzed with Benzoyl Peroxide, so obviously the other stuff would just harden it, and probably break down in the process. Polyester casting/laminating resin is "kicked" with just a drop or two of 50% MEKP, so that's out. I've even used MEKP instead of BP with Bondo, which roughly doubled the working time (or "pot life," in the composites lexicon).

However, I see no obvious problem with using Polyester with a Nitrate Ester. Especially not cost. Bondo is shit-cheap, and Mineral Oil is cheaper.

Also, If you want to make a rigid shaped charge, just mix your PETN with the stuff and then catalyze it as you normally would, omitting the oil. I'm unsure of whether or not the catalyst is just along for the ride, staying chemically intact, or if it's more of an adduct, actually reacting with the monomer and forming a new molecule, rather than just making the existing monomeric resin molecules "hold hands." If it turns out that the Peroxide stays intact, and enough can be mixed in before the resin hardens, the possibilities boggle the mind. Imagine a hard, stiff binder packed with HMTD and PETN. The high compressive modulus of the Polyester would ensure that very little of the VOD was lost due to cushioning between particles. In fact, the binder may transmit the detonation forces more effectively than simple compression, possibly increasing VOD over that of loose, tapped or even compressed particles.

And then theres the whole family of UV-cures resins, mostly Polyester, but some Cyanoacrylates, as well.

Then again, maybe brown, smelly stuff will start oozing out of my ears any minute now. You decide.

I'm only about half way through reading this thread, however, since the last thread is still talking about plasticizing PETN I figured this probably hasn’t been posted yet. Back in the day, when I worked construction, I used a window sealant that was pure polyisobutylene. I found this: http://www.dkhardware.com/product-24911-pt1707gry-gray-pti-707-butyl-rubber-sealant.html It is not the same brand but I think it is the same stuff. The description sounds the same. If so it would be a cheap source of butly rubber.

I read a couple of more pages and someone did mention butly rubber caulk, also that he found straight polyisobutylene, which is what I posted. I'm almost done reading this thread and haven't seen it mentioned again, or that anyone has tried it.

On another subject: I've seen quite a few different methods for PETN. I’ve been considering dissolving 25g PE in H2SO4, to avoid temperature issues, then adding to 150ml HNO3 70% & 50ml H2SO4 98%. Is there any reason not to use less acid? Powerlabs, http://www.powerlabs.org/chemlabs/petn.htm, only uses 34ml 70% NA and 25ml 98% SA with 10g of PE and gets a 90%+ yield.

As for neutralizing, it appears that some people use an acetone bicarb solution while others neutralize then dissolve in acetone. Is this just a difference in preference or are there significant benefits to one method over the other?

As for neutralizing, it appears that some people use an acetone bicarb solution while others neutralize then dissolve in acetone. Is this just a difference in preference or are there significant benefits to one method over the other?

To properly neutralize PETN, or really any high explosive, you must destroy all traces of acid locked up inside the crystal structure. This is impossible to do by simply washing the product repeatedly with bicarb solution.

In order to get at these well hidden acidic molecules, we must dissolve the crystalline explosive in a solvent (eg, acetone), and then crash it into a basic solution. By dissolving the crystal, it allows us to access every last bit of acid.

If an explosive is not neutralized properly it will usually begin to decompose. This is quite obvious if you've ever seen acidic ETN stored, it gets a layer of NO2 floating above it from breakdown.

Funnily enough, I have had quite good experiences so far with neutralizing my energetics. Each time I have used a 4-5% Sodium bicarbonate solution, and left it to sit for minute or two, with some nice stirring to really mix the solution up.

I have never needed to recrystalize any of them yet. I have had my ETN for about 2-3 months, and it's still as good as it was the day I made it. Same goes for HMTD. I have had that for 5-6 months and it is still completely fine. No increase in sensitivity at all, and still retains a fresh white colour. My RDX has been the same aswell. Have had that for around 1 month, and it is completely fine.

From this I gather it certainly isn't necessary to recrystalize your material to end up with a stable product, as it can be done from a good wash and neutralizing. However, it does become an important issue when striving for a highly pure product, with more preferable and uniform crystal sizes and shapes.

I was interested in seeing how certain materials would store, so this is the reason I kept hold of samples, and let them sit untouched in safe places for periods of time. None of them are stored in air tight containers either, just merley sitting there in their containers, open to the air and dry.(Well out of reach I must add).

I personally think that quality of precursors have a great deal to do with it also. Contaminats introduced into your mix during the synthesis stage, and low quality chemicals probably have been mostly to blame for people ending up with crapy end products. The biggest suspect being some of the low grade, shitty H2SO4 sources that are used. Low quality drain cleaners and and dirty battery acid are most likely the ones to blame.

Back to topic, the PIB sealant looks quite a nice source. I haven't been able to experiment with it quite yet, but soon I will be playing around with the plastics idea again. I went for the PIB tape route, then I will dissolve this in a solvent, mix it with the chosen energetic and silicone oil, and evaporate the solvent away.

Emil:
How long are you planning to keep you samples stored? I know someone on the forum stored samples of (I believe it was AP) for extended periods of time, occasionally trying to see if it was still usable. I would be curious to know if your samples are still good at least a year from now. 2-3 months for your ETN or RDX isn't very long at all, are you planning any 1-2 year long storage tests?

Yes that's it. I am interested to see the "shelf life" of them, and at which point (if any) they start to deteriorate in performance. I have a good control for ETN and HMTD also. I know that I cannot detonate ETN by striking it with a hammer, so over time that simple test will be used to try and note any differences. My HMTD needed a fairly decent whack to initiate also, so as time goes on I can test them again.

I do not have any figures for their detonation sensitivities, So I cannot provide any "precise" details, but I myself know how they acted under basic conditions so will be able to note down any changes.

The RDX is relitively new, and isn't really any use in this test. Unless there is something seriously wrong with it, it is never going to be initiated via a hammer blow as it (Should be) way too insensitive. However I can just leave it there to sit and see how it behaves. It's also interesting to me as none of my samples have been recrystalized. I would be pleased it any of them became one year old and still behaved correctly, any longer would be a bonus. But yes I will try and keep them for a couple of years and see what happens to them all.

I think I will test them soon. The HMTD has been untouched for about 4 months, and the ETN was tested a few days after it was made, which means it has been untouched for just under 3 months.
HMTD would impress me the most if it remains usable, beings as it's a sensitive peroxide primary in the first place. It seems to behave more sensible than it's infamous brother AP. I seem to get the feeling that AP does not store well judging by previous seen posts. I personally have never made it, and don't ever plan to, so I won't be finding out first hand.

Emil:

I think you should re-think your tests and expectations for the stored explosives:

- The hammer test is quite inaccurate (if the hammer is swung manually) as it is impossible to strike exactly square to the surface. This introduces large errors. If you want to do an impact sensitivity test, you have to make a drop hammer apparatus instead (not that hard to do).

- I'm not at all convinced that an increase in impact sensitivity will necessarily be the consequence of decomposition. For this reason I think you should determine the change in weight of your samples over time rather than just the impact sensitivity.

- Instability due to incomplete neutralization is much more pronounced (and much more of a problem) at elevated or cycling temperatures. So if you prepare a charge that is going to be exposed to real world climates for extended periods (maybe sitting in an outhouse during hot summer days), then you want well neutralized explosives.

I know that I cannot detonate ETN by striking it with a hammer,
By not re-crystallizing your product you are introducing a variable. Just from a personal perspective I would not even consider the synthesis of an energetic material if no quality-assurance / purity provision mechanism was going to be part of the lab.Re-crystallization is vital for many reasons but for sake of this discussion; it would be a "apples & oranges" comparison.....

Every single sample of high quality ETN/PETN (or even RDX for that matter) has initiated from a drop hammer of a 2lbs mallet sledge swinging on a pivot of a large construction nail onto a steel surface. One of the discussion points on the agenda of DuPont when they had bought up the US production patent rights to ETN aside from price of the base material was the sensitivity of the finished product.

I have heard variations of crystal shape being a discussion criterion of impact sensitivity but never have I heard anyone say that ETN was not one of the most impact sensitive dry N-esters they have ever experimented with. You just can't get it pure enough without re-crystallization to be of any use in such an experiment.

Those are some good points, and maybe I should look at how I am going to carry out any accurate tests, rather than being vague.

The problem with weighing my samples is that without a decent scale, it is a waste of time. The scales I have seem to be a bit up and down, and throw different readings at you as they feel like it. I have to invest in a decent set soon, but as of yet, that is the reason I haven't bothered with that.

I think it is a good idea to build a drop rig, so this way I can get some nice figures down. I will go ahead and construct one in the coming weeks.

Charles:

I am not in any way trying to make out that the un-crystalized product will be near the quality levels of a re crystalized one, neither am I cutting corners by doing a rushed lab just to get the final product. I was just interested to see how they really fair up against each other. I know damn well if I was going to be keeping my product, I would want it at the highest quality level possible.

Actually by "non-re-crystallization" (to use a bizarre expression) the material is actually not completed. This is not too easy to follow so bear with me....

The crystal structure insures that the molecule does not have contaminants and the material is not inundated with either acids or water. By not taking that step you introduce a variable that will throw off your work virtually every time. The impact on the crystal surface is what introduces the "hot spot" that is critical to initiation from impact. The powdery material of the first nitration is not consistent enough from run to run to allow various comparisons in home-lab conditions. To accomplish comparisons you actually have to re-crystallize.

A trick that can be used is to make a balance scale (a simple thing, really or make a nice one: doesn't matter) and remember that a US Nickel is 5 grams.....Bingo: you have a scale.

Is 7 an acceptable PH level for PETN? Or should it be re-neutralized?

Imho, 7 is good. They do say to wash until neutral and 7 being neutral... I say that 7 is grand. What do you intend to do with it, store it, make plastique, blow something up...? Because that does matter. If you intend to store it make it 8 just in case.

Thanks for the info. Why a PH of 8 for storage? The yield was pretty crappy, 34grams from 25gram of PE. I kept the temp under 10*C during nitration. I think I should have warmed it to 40*C and kept it there for 20-30 min. Anyway. I think I’ll try to plasticize it with the butly rubber sealant that I mentioned in the previous post.

Yield is related to the level of HNO3 used, temp and variables such as nitration exposure time as well as the quality of the initial precursors. Not knowing these, it's actually difficult to predict of that was a poor yield as a mixed acid nitration with poor materials could well show results of high 80's with those two figure (& the 10 C mark); that being acceptable for low level HNO3 percentages, etc.

Interesting example: There is a penteuythritol that is commonly used in the vinyl siding industry whose purity level is rather low and actually contains some contaminants on the level above 6%! Using such a precursor together with a mixed acid of drain cleaner and a solid nitrate and you have a DAMN good yield if you achieve anything over a "break-even" mark of initial ingredients.

Most lab specimens are one sided nitric acid nitrations using nearly anhydrous HNO3 and reagent-grade precursors. The vinyl siding material would be considered completely unacceptable in the general standards used in all NATO countries and perhaps even as far back as WWII.
-{Now you understand why I'm so pushy with the re-crystallization issue}-

I have only made PETN once and I used reagent grade chems. The nitric was stolen from an undisclosed place (Hey, it was left unattended) and the pentaerythritol was also pure, ordered off a chem supplier through my school. I used the ratios in a text I will attach later and found the product to be damn good. I lost my notes though and it was about a year ago. I do remember it having a pH of 8 and being stable for 3 months, dry, in fluctuating temps.
*edit* View the attached 'text file' to see the procedure.

Charles; I used 150ml 70% HNO3 & 55ml 98% H2SO4 and 96% PE. All from chem supply places. It seemed like quite abit was lost in the neautralizing process. I may have not used enough water to precipitate the PETN out of the acetone.

HEX; thanks for the txt. Why would I want a PH of 8 for storage?

armchairsapper: I find that with most explosives that need neutralization that leaving them slightly basic in storage helps to prevent the formation of NOx Gasses and decomposition over time of the sample. I even do this with ETN that has been recrystallized twice as a just in case.

I also have a tendency to store my samples in old, well washed out, brown peroxide bottles to keep the sunlight out also so I may be just a bit too paranoid. Better safe than sorry as they say! I store 320 grams in a 250 ml bottle which also makes a nice charge container. In what do you store yours?

Realstically using the 65-70% tech stuff is not a standard and an adjusted 72% yield (I did that in my head, so it's off - but close) is fine really. The industry simply doesn't use tech-grade acid. They used in situ anhydrous and a flush mechanism so they (someone like Dynamat-Nobel) get serious returns. As long as you're getting the principal down and have a slide to stick under a microscope; you've been successful.
That's fine for the investment also....think how much those guys have into their plants?

If you want to know what going on in the industry today, get a copy of the Journal of Explosives Engineering and check out the ads for SEC. Energetic-sys.com (Oklahoma City OK) does the newest shit with Slurran, Detagel, PermEx, & have bought up Kinepak. They have all their techniques in huge glossy color ads.....It's like porno. I'm actually serious. They have these pictures of industrial energetic materials that are arraigned like....Like...well, you know. Then there are ads with girls in very short skirts holding sausage shaped cartridges bending over a bore-hole....It's really pretty funny. They use what they call "de-militarized blends" (600-20/600SLX) that are very obvious and actually not that original. Most returns are at a 90% level I imagine.

Hex; I have some black ABC plastic pipes that I use for storage. PETN is the first that I've made with acids. Every thing else has been ANNM or chlorate based.

Charles; Thanks for the info! It was my first attempt at any acid based energetics so I'm just glad I didn't screw up. However, I was hoping for a better yeild. But now that I have the process down and I can work on refining it. I'll have to find a copy of the Journal.

I should be able to get a chance to try that polyisobutylene sealant this weekend. I'll be sure to let you guys know how it works out.

It took me "forever" to find Pentaerythritol.

NO SOURCES - Enkidu

I managed to purchase some 60% nitric acid and 95-98% sulfuric acid from near chem supplier. Still I haven't found any source of pentaerythritol and therefore weren't able to do any of it. I, and many others too, would be curious to know if there are any known suppliers for PE that would deliver 0.1-25kg amounts of it in Europe. [This is against board rules. No public soliciting of sources. - Enkidu]

I have wondered on some plasticizers. Might a Play-Doh or Blu tack, stuff that anyone gets just from any shop, would work in any way? I tried to carefully rub some small pile of AP into blu tack, but obviously quantity was too small since it just cracked few times.

@Setharier:
Armchairsapper and others were speaking to really making the commercial equivalent product. Yes, you could put some energetic material in some plastic crud and it may shoot but the idea is to come as damn close to the original as possible. You want the real thing here. Do yourself a favour and read back -through this thread and the ETN threads and your questions will eventually be answered....(seriously).

Issues regarding public soliciting of sources is obvious in it's importance. If you pour over this stuff: it's all here anyway. You actually don't even NEED some address IF you know the originating information of the product within commercial industry.

WTF!! Is it possible to use too much bicarb when neutralizing and destroy the end product? I tried again and had a great yield (87grams)... but it will not detonate! I dreamt of: dissolving 35 grams PE in 10ml 98% H2SO4 adding to; 150ml 70% HNO3 & 50ml H2SO4 which was cooled to -5 C overnight; adding mixture to a water bath bringing the temp up to 40 C and nitrating for 45mins till mixture turned yellowish cream color to a darker yellow. Crashed into ice cold water (mixture turned white); filtered; dissolved in acetone then crashed in an ice cold heavy bicarb solution. Filtered; dried; got some nice white crystals that will not detonate.

Placed about 2grams in a 1/4 AL tube with .75 grams DDNP. DDNP went off but the PETN did nothing! Where did I go wrong?

First off, would it be all that difficult to synthesize an energetic binder similar to some of the stuff the big boys are playing with? It seems like a new thread, or maybe even a subject area, could be started, if enough people want to persue it.

Question: The only HNO3 I can get right away (and 7-4 comes up fast) is 70%. So I'm wondering if I could use a Molar equivalent of 100% and toss in some H2SO4 to grab up the water & facilitate the nitration. And yes, I've read the whole thread, but after 20 pages or so, it's hard to recall if there was any discussion of that particular subject without taking paper notes.

Maybe that's another area for discussion: Things you can do (and can't) to avoid having to go through a distillation preocedure for this-or-that particular end product. Perhaps a list? Or working up some sort of equation or tables or something?

Armchairsapper: are you sure you didnt pack the PETN too tightly? Was it pure dry? No, you cannot over bicarb it...

Yafmot: next time I am on a proper computer (After the exams) I will attach a file I have about making PETN with lower concentrated nitric acid. My pm function doesnt seem to work so I couldnt reply to your message about coilguns. It only works on my computer. Anyways there is a way to make PETN and it is not different from the method you suggested.

Well energetic binders shouldnt be too hard for us here on roguesci... Maybe a melt cast mixture which is moldable? Microtek did some work on that iirc. Maybe NC and a non volatile energetic solvent? Maybe like blasting gelatin?

Yamfot, I think you will find that is what most of the guys here are doing anyway. They all seem to be using the H2SO4/HNO3 route, probably because they do not have the means to attain any fuming Nitric. As you know, the best way would be to use fuming Nitric and not bother with the H2SO4, but judging from the feedback from this post, the former seems to give very give yields and does not dissapoint.

This is what puts alot of people off of RDX, people who do not have the equipment to distill the fuming nitric haven't got any other alternative. OK you may say how about the Acetic Anhydride route? But in 2008 drug precursors aren't really the smartest thing to go buying up.

armchairsnapper: What percentage of bicarb solution did you crash your product into? I usually use around a 4-5%, although I have heard for some high explosives a higher number around 10% being used. I wouldn't thought the bicarb could destory your product, as it is really only there to act on the remaining acid. Did you recrystalize your product???
Charles is the guy to speak to about this aspect, as I recently learned from him that failure to recrystalize your product, is actually cutting a the synthesis short, and not fully completing it.

Impurities could actually act in an opposite effect, and instead of causing your material to sensitize over time, it could actually obstruct/diminish it's performance, possibly to the point of not being able to shoot it.

I couldn't imagine this is the case for you, as I imagine your batch it relitively new?? How can you be sure the PETN didn't shoot?? I wouldn't just rely on your audio to define whether it did, as if you were wearing ear protection (like you should have been ;)), then it could be hard to define.

Maybe building a test drop rig will shine some light on your results.

Hex; I did press it in quite tight using a hand press. I have no way to measure what the psi was. It was dry. I didn't think I could destroy it with bicarb but the only other thing I can think of is that the PE was poor quality.

Emil: I crashed mixture into cold water; filtered; dissolved in acetone; poured into cold bicarb solution (not sure of the exact %); filtered and dried. Should I have taken another step?

It was quite depressing when it did not detonate. I made about 2ft of detcord which I was also planning on testing. I'll try another cap without pressing it, or at least with minimal pressing.

I wouldn't worry about pressing being the problem. Using a hand press, it is impossible to reach the max density for PETN of 1.7 g/cm3. If you were to exceed that, then dead pressing could be an issue, but since you're not reaching near that density, I doubt that is the reason.

You could do a simple drop test on the PETN. Or you could put a small portion on a hot plate and heat it to 190*C or if you don't have one, place it on a metal surface and introduce a flame underneath it. That is how I usually test my ETN product. It reports with a quick pop and a small flame. Be careful not to put too much. If you're at a critical mass, it will go high order in the your face. I've never had that happened before :o Wear eye and ear protection...

I wasn't there, but if I was in your position, I would first increase the nitration time of the product and keep a close eye on it. Then if that didn't work, I would guess it had something to do with the bicarb. Maybe your conc. of bicarb is too high and is interfering with the recrystallization? Is the bicarb solution made with distilled water? Also, what is the quality of your reactants? Unfortunately there is usually no quick fix, unless you get lucky and find the problem your first try. Keep good lab notes and follow the clues :)

Thanks for the drop test suggestion Rbick. I'm at a complete loss as too why the PETN in the cap didn't detonate. I smacked a few grains of PETN, same batch as the cap, with a ballpeen hammer and it detonated fine.

If someone is using TATP for a "primary".....that could be one reason. PETN is a standard industry / military level professional material. TATP could be termed often a product of Abdulah's fanaticism rather than an equivalent professional primary material.

Good point Charles. I'm use to shooting ETN, which is a bit more sensitive, so AP never has a problem initiating it.

While there are excellent primaries that are azides and fulminates, I would recommend HMTD. It is sensitive, but if extra precaution is taken, you should be fine. HMTD beats the hell out of AP, and performs as well if not better than many primaries. It was actually considered for commercial use but dismissed due to its sensitivity. It is also made from easily available materials.

Also be aware that density has a huge impact on the effectiveness of a primary. If you just pour the primary into the container without pressing, its not going to have much power, leading to no detonation of your base charge. This is a simple formula you can use to roughly calculate VoD.

Vp1 = Vp2 +3500 (p1 - p2)
V 1 and 2 are the VoDs for densities p 1 and 2 respectively. 3500 is a constant. AP has a max VoD of 5100 m/sec at density 1.4 g/cm3. We all know its damn near impossible and suicidal to try and press AP to that density. Lets say we realistically get it to around .8 g/cm3. We are solving for Vp2.

5100 = X + 3500 (1.4 -.8)
X = 5100 - 2100 = 3000 m/sec

Thats a big difference, big enough to not initiate your base charge. It is a common misconception that the listed VoD of an energetic is constant, whereas this is nowhere near true. The max density for HMTD is .88, which is much more reasonable than that of AP, and it is less sensitive than AP as well.

Anyway, sorry I got a little off topic. Give HMTD a try or an alternative primary with your PETN and see what happens. I'm glad to hear your drop test worked, so at least we know now that you have working material :)

All right. Then we are facing another problem not only related with materials to make it. I quess surely HMTD(RE 1.6) will go much better instead of TATP(0.84)? Man, we still need that hexamine anyway..

Well, you could make Azides quite OTC by using the synth from hydrazine sulphate made from bleach and ammonia and sulphuric acid. That synth will be in my next .pdf. Or you could do as I have done and just outright order it from a chemist or pharmacist. The synth is not too difficult. Merely time consuming.

I believe Armchairsapper has used DDNP in the past so making the azide should be no more painfully frustrating than that synth. TATP is not a good primary at all. maybe have some ETN as an intermediary in the cap between the primary and the PETN? If you dont get that I will upload a diagram.

Oooh PETN detcord! Shiny! Please tell how you made it! how interesting! Also, Rbick, HMTD is not a good primary at all. I made some in a rather large batch and disliked it so I destroyed the 50 grams in a Test I mentioned here in one of my first posts.

That said, try Azides. Its not too hard, just time consuming.

Rbick, HMTD is not a good primary at all. I made some in a rather large batch and disliked it so I destroyed the 50 grams in a Test I mentioned here in one of my first posts.

Not according to COPAE. Read the HMTD portion located on page 451-453. Studies in the text show that HMTD outperforms many primaries in the ability to initiate base charges. Other studies show the same results. The reason it was not picked for commercial use was merely due to stability issues and decomposing when exposed to air for too long.

Direct quotes:

Its explosive properties commend it, but it is too reactive chemically and too unstable to be of practical use

In the sand test it pulverized 2 1/2 to 3 times as much sand as mercury fulminate, and slightly more sand than lead azide

It is considerably more effective than mercury fulminate as an initiator of detonation.

When they say "Too reactive", they are referring to the exothermic reaction and decomposition that occurs between metal and HMTD. This can be avoided easily by the use of non-metallic caps or lining the cap with something as simple as paper. My personal experience with HMTD has been good as well. I have gotten much better results with it than AP or Lead Azide and in some cases it eliminated the need for a booster. With this said, I think HMTD would be a reasonable primary to try with his PETN, plus it is easy to make and not time consuming. Of course it is a matter of choice, but either way, changing the primary is the first step in solving this problem.

Armchairsapper, when you have technical grade pentaerythritol, it probably contain some (5-10 %) dipentaerythritol, which, when nitrated to -hexanitrate, less effective and less sensitive to shock than PETN (and DiPEHN have much lower melting point, but less stable at higher temperatures than PETN). Despite of this, I do not think this is the cause of the unsuccessful detonation.

Rbick,
The max density for HMTD is .88

I found this info in Fedoroff, volume 7, H-83 L
HMTD density in g/ml pressed with a given pressure:
1.05 g/ml at 100 atm
1.15 g/ml at 200 atm
1.30 g/ml at 800 atm
In Urbanski, volume 3, page 226:
specific gravity: 1.57 g/ml
apparent density: 0.66 g/ml
with 170 kg/ccm pressure, 0.91 g/ml obtainable

HMTD Velocity of detonation at given density:
from "Fedoroff", in 0.22" pipe:
4511 m/s at 0.88 g/ml
5100 m/s at 1.10 g/ml
from "Urbanski", in 5.5 mm pipe:
4510 m/s at 0.88 g/ml

HEX; For the "detcord" I just ran the PETN through a screen, then used a funnel to add it to a length of 1/8th in plastic tubing. Tapping the side of the plastic tubing helped to "settle" the PETN. I haven't had a chance to test it yet or the butly rubber caulking that I mentioned earlier.

Back in the day I have used HMTD. Lately I've been using DDNP, although I have not made it. The PETN was my first "synth", most everything else has been binary compounds. I'm going to try my hand at making my own DDNP.

Do you have a way of pressing it? The performance would be greatly improved if you found a way to press the PETN into the tubing. After tapping some down into the tubing, I have used a long, thin wooden dowel to gently press the explosive further. There is also a discussion about using compressed air. Your photo looks great though. Cutting down some trees? :)

drsx, Thats some good info. I should have been more clear. By max density, I meant the most reasonable density that performs well. You can press anything to ridiculous levels with enough pressure. I'm guessing at passed that point (.88 g/cm3), dead pressing would become an issue. Point being, this density of max performance is much lower than that of AP.

I've been thinking about a good way of pressing it. So far the only viable solution I've come up with is using a dowel like you mentioned. It helped that I was able to reduce the crystals to a very fine powder with a screen. Also, after filling a couple of inches I would whip it, very gently of course, in between the door to a cabinet and the cabinet itself. That helped to "settle" the PETN a little more. As far as plans; I was thinking about cutting a branch off a tree with half and if that went well then using the other half to initiate some plasticized PETN.

For pressing, I think a 2-3 tons hydraulic "car-jack" (or "car lever"?) combined with some weight from 10 to 100 kg worth a try. I will try it, but unfortunately, now it's beyond my possibilities.

Rbick,
I'm guessing at passed that point (.88 g/cm3), dead pressing would become an issue.
From Fedoroff: "It [HMTD] does not become dead-pressed even at pressures of 11000 psi [...]", unlike, for example, MF.
Since I do not want a ban, I think we should go to the adequate topic with the discussion about HMTD.

I think we should go to the adequate topic with the discussion about HMTD.

http://www.roguesci.org/theforum/showthread.php?t=367

There is an entire thread dedicated to HMTD.

The butyl rubber caulk I mentioned previously worked OK. Better than Vaseline or other oil based plasticizers. The putty that it forms is does crumble more than the real thing though. The caulk wasn't pure polyisobutylene as I had hoped. It is somewhat "tacky" but not sticky; if you handle it for awhile it will leave a bit of residue on your hands.

VERY high quality flake Aluminum is often used to lubricate the compression of a material (for example with a tube) wherein the need for dry lubrication and attendant maintenance of energetic properties are important.

The ball in the pic is a mix of PETN & 4 micron AL powder; about 10%. Since I posted the pic it has lost it's "tackiness" and no longer leaves a residue on your hands when handling it. Also it seems more plasticky (if that is a word). When I mixed it I diluted the caulk in acetone & liquid paraffin.

And how much rubber caulk is in it? Also, how much does it weigh (in my experience scale makes a difference)?

Excellent work. Now Test its explosive properties against straight PETN, PETN with aluminum, and the PETN and nitroglycerine plastique, and that plastique with aluminum. Then record the results and work out the loss in power. Then we can see if it is really worth its salt.

I was surprised to find that the caulk did not dissolve in acetone. I had to add a bit of liquid paraffin. I'm not sure the exact amount caulk. I kept adding it till was completely mixed yet not sticky. I'm trying to make DDNP but I screwed up twice making picric acid with nitric acid. I'll try again with the standard SA & KNO3. As soon as I get some good caps I'll post the results from the plasticized PETN & the detcord.

Microtek; it weighs 78 grams.

WOW! If I'm reading this catalog I've found correctly, I just hit big time pay dirt! I stumbled across an outfit called source removed that sells just about every plasticizer imaginable. Source has been removed per rules

They've got monoesters like Oleates, Palmitates and Stearates. They've got Diesters like Adipates, Azelates, Phthalates and Sebacates. They've got Polyesters, other polymers & polymer oils, Epoxy plasticizers and lots of other shit.

Diisosebacate is what they use in C-4, and it seems, offhand, like Azelates might add a little punch to the product. A Methyl Azelate might do that plus add even more due to the positive Oxygen balance of PETN.

Then again, I might be completely full of shit on this one. The catalog is unclear as to whether the listings are for plasticizer kits, or plasticizer DETECTION kits. If it's the latter, at least they may be able to steer us toward the proper sources for these goodies. I'll look into it.

Also, I might have it wrong on the Azealates in general, and the Methyl Azealate in particular. I was guessing at the chemistry, going by the name. We'll see.

Nice find there by the way. Plasticizers must be one of the hardest products to buy OTC, especially some of the ones they sell! I'm going to have a nice look through that later on.

A question I do have, if anyone knows, but what solvent do they actually use in the manufacture of C4 When dissolving the plasticizer and binder? For some reason I can't seem to find a specific patent on C4 itself, most of the patents seem to be other plastic explosive compositions etc. Any help on that would be nice.

Emil: according to kitchen improvised plastic explosives, the solvent is simple gasoline. I am not sure of the accuracy of the book though. I would guess that it would make a good solvent though, being volatile enough to simply evaporate off the explosive.

As regards PETN I personally think that plasticizing it with polyisobutalene to form a sticky explosive is a good idea. Never mind blue-tak, its boom-tak! When I get my pentaerythritol I will do a experiment with that plasticizer. Maybe I will try it on ETN soon.

If my understanding of "standards" is correct, what they're selling are examples of each compound, to be used for analytical study.

I noticed the site is quite old- it says, "Download our NEW 2001-2004 Pesticide & Metabolite Catalog".

Also from their site- "We supplies analytical reference materials and small quantities of organic chemicals.

We provide highly purified organic and inorganic chemicals, solutions and mixtures, and chemical kits, suitable for use as analytical standards and reference materials, and for other laboratory purposes.

We have the largest selection of pesticide and metabolite reference materials, including many banned and discontinued substances."

In any event, I've ordered both catalogs. I'll report back if/when they're received.

I have removed the sources in the posts above. This is so that not every kewl can use and abuse the source. If you would like the source, you can PM Yafmot for it or if Yafmot ever becomes unavailable, you can PM a mod.

PM Yafmot first.

We have no problem with sources being shared, but we do have a problem with them being lost because a horde of kewls abuse it. Hence, general sources are ok (Bunnings, Home Hardware, etc) but specific sources shouldn't be posted to be abused. Just post what they offer, and ask users to PM for the source.

what solvent do they actually use in the manufacture of C4 When dissolving the plasticizer and binder?Check into methylene chloride for that. IIRC, that should work, although I don't know that it is what is used in the "commercial" manufacturing process.

And methyl chloride, but that may be problematic.

Acetone won't work.

A question I do have, if anyone knows, but what solvent do they actually use in the manufacture of C4 When dissolving the plasticizer and binder? For some reason I can't seem to find a specific patent on C4 itself, most of the patents seem to be other plastic explosive compositions etc. Any help on that would be nice.Ordinary white spirit will do the job, or some other hydrocarbon maybey, the big problem with home C4 manufacturing is getting the plasticizer/binder contend down to 9 % without everything falling apart;).

And creeping up to 15 % results in better moldable properties, no original C4 anymore, and plastic splattered everywhere from a 0,8 grams PETN booster:(.

By the way, I made a little omission on my last post. C-4 is plasticized with DIOCTYL Sebacate, and the stuff that place offers is Isodioctyl Sebacate,which probably just means that some component of it is isomeric which, in turn, could mean it's less refined. And I don't think they use any kind of solvent at all in C-4. The reason for that is that solvents eventually migrate out of the package, and also may tend to segregate into discrete areas of the block, which can result in uneven handling and uneven detonation, as the wave encounters different densities through the charge. No solvent, no change in properties, and these plasticizers are generally solvent free. They're very oily though, and that's the trick. Start thinking mineral oil plus monomers and other polymer precursors.

According to Mark's Standard Handbook for Mechanical Engineers, C-4 contains RDX, 91%: Dioctyl Sebacate, 5.3: Polyisbutylene, 2.1: Oil, 1.6. As you can see, no solvent.

Come to think of it, I think that modeling clay they use in detroit for car body design uses sebacates in it. It's really crazy; all the Big Three use their own "Secret Formula" clay, and they all get it from the same manufacturer! This goes for the BMW, Honda, and other design studios that build life sized models as well. Ive got a connection to that manufacturer through a friend of a friend, and I may be able to find a good source of Sebacates and other plasticizers that way. I'll see what I can do.

Oh, lawdy! Aint' it great to live in a country where you can put two and two together and get God knows what?!:D

So, whaddaya' think?

For some reason I can't seem to find a specific patent on C4 itself, most of the patents seem to be other plastic explosive compositions etc. Any help on that would be nice.

Ordinary white spirit will do the job, or some other hydrocarbon maybey, the big problem with home C4 manufacturing is getting the plasticizer/binder contend down to 9 % without everything falling apart .

And creeping up to 15 % results in better moldable properties, no original C4 anymore, and plastic splattered everywhere from a 0,8 grams PETN booster.


Whatever you do with your methods, even if you use the exact formulation, you will never get the desired consistency as there is always the tendency to exceed in the use of the plasticizer/binder mixture so your plastique always contains slightly lesser explosive, than the real thing.
The essence of the original C4 technology is the technique- which was to create a sort of explosive molding powder by dispersing a bimodal composition of different crystal size of RDX in a plastic binder with just enough softener or plasticizer to make it moldable in any shape.
It’s originally made by the a two stage process.

It’s done first, by preparing a sort of a lacquer by dissolving the binder in the suitable solvent, then add the plasticizing material then when they are properly dissolved ….
A slurry of granular explosive and water is made, and heated to between 60 and 70 deg C, then the lacquer composition is added in and stirred at high speed; then the heat is raised to the boiling point of water , then its cooled back to around 65 deg C,( with continuous agitation) then vacuum filtered to remove much of the water.
Its then dried in some sort of oven (or even a forced air drier) to remove residual moisture until it forms a granular powder where the explosive is tightly bound by the lacquer film . To form the C-4 block, they are pressed to the desired shape by an appropriate equipment.

Actually the C-4 is extruded into the form needed, usually the M112 blocks.

Actually the C-4 is extruded into the form needed, usually the M112 blocks.

Originally when they were first formulated they were just pressed into shapes... Extrusion was just a later development.

Hooo-Hah! I just arranged for the delivery of four pounds of PE in four different grades. All por nada. Free of charge. And no, I'm not ready to divulge the particulars of how or where. Don't wanna' mess up a good thing. Maybe later.

One thing I'd like to know is whether anyone has used stump remover straight from the jar, and whether there is any real advantage to recrystallizing the KNO3 before proceeding with the synth. I know Grant's is 98%, but I'm unsure of what constitutes the remainder. Has that even been determined?

I can get 96% HNO3, and 98% H2SO4, clean but pricy. Maybe I'd be better off going that route, since I've heard that KNO3 can get mighty hard to stir for 20 minutes. I'm thinking about designing & building my own magnetic stirrer, as the store-bought items seem ridiculously overpriced.

I've also thought up a cheap, fairly high capacity vacuum dessicator. All you'd need is a plate of tempered glass shelving (available at a used store fixtures supplier), a sheet of low durometer rubber (Most grades of silicone would work), a stainless mixing bowl, a drill, some tubing, fittings & washers, and one of those cheap brake bleeding kits from Harbor Freight.

Just drill a couple of holes in the bottom of the bowl, one for the vacuum, one for a relief valve. No welding or soldering would be needed; rubber washers should do the trick, fittings and valving are at your discretion, and then you just place the rubber sheet flat on the glass plate, set a plate with the substance to be dried on the rubber, set the bowl, inverted, over that, close the relief valve, open the vacuum port, and start cranking away on that little hand pump. The pump comes with an integral vacuum guage on it, and I see no reason why you couldn't pull 28" Hg or more. Got a slow leak? Just give the pump a few grabs now & then to maintain vacuum.

If you waned to get a little more elaborate (and efficient) you could plumb in a dry Nitrogen inlet and then cycle it from vacuum to N2 @ ambient, back to vacuum, and so on. making the process much more rapid. And you could add heat by applying a "stick-on" heater to either the bowl or the bottom of the glass. Or you could get real fancy and install a leakproof electrical passthrough to a heater stuck onto the bottom of the drying plate.

So, whaddaya' think?

I would re-crystallize the KNO3 from the jar. Pure as it is, you can get tiny crystals, instead of prills which would be somewhat wasteful. Just dump the jar into a few cups of boiling water and dissolve. I usually let it sit for a 15 minutes and then stick it in the freezer till it all comes out, filter and let dry.

As for the synthesis you are planning to use it in, I would stick with pure HNO3. Consider yourself very lucky that you can synth PETN and have the reagents to do it. I've only had the opportunity to synth it twice myself, and I am very well equipped.

As for magnetic stirrers, you should check ebay for air powered models. I have one exactly like mega's, and they are excellent little pieces. Just attach a vacuum pump and you have a high torque little unit that will stir even the most thick nitration mixtures. They are a bit cheaply made, but very sturdy.

On the magnetic stirrer - I'm sure you could scrounge up some old PC case fans and a 12VDC wall adapter and you could make your own stir plate. I did this awhile back, but due to poor construction on my part, I ended up finding another hotplate/stirrer for very cheap. You can google "homemade magnetic stirrer" and find quite a few different creations, but the one I liked was this one (good pictures):

http://brewiki.org/StirPlate (http://brewiki.org/StirPlate)

This would be very easy to make and should cost under $20 if done with spare parts.

On the KNO3 - I would do as totenkov directed and recrystallize the KNO3. There is always the slight chance that a random chemical could contaminate your synthesis or end product and react in an undesirable way.

On the vacuum dessicator - Sounds like a great idea. You may want to put an in-line one way valve between the bowl and the pump to minimize leakage, as well as making the silicone sheet more of a washer shape so that it does not take the form of the bowl. Then just heat the glass and fill with your choice of dessicant.

On the PE - Lucky! I've been looking for a supply for some time now, and I came to the conclusion that I was going to import a "sample" from China. Maybe I will keep searching in the US.

I believe nuke-slo will have something to contribute, he makes a fair bit of PETN in his time. I will have a load of Reagent grade pentaErythritol soon so I will be joining club PETN. Anyways I like the dissicator design, it looks Damn good. Anyway I personally advise using the nitric acid, unless you are saving it for RDX.

Oh well I will describe some of my experiences with PETN…

I didn't document some of my very first PETN synths, but I managed to documentate most of them.

I followed powerlabs's procedure I didn't recrystalize it tho... No pictures only some pretty crappy video.
I used the whole product (~20grams) and 3grams of HMTD for detonator:
http://www.youtube.com/watch?v=YdVKhokiinE
Notice the launchramp behind charge? It was meant to be rocket launched charge but my friend's ignition system for charge failed and rocket was very unstable(good thing it didn't detonate) I decided to detonate it on ground.

Ok about a year ago I made a paralel nitration:
2x10g PE, 34mL 65% HNO3 and 25mL of 96% H2SO4 in two 250mL beakers.
Picture of workplace: http://i242.photobucket.com/albums/ff11/NUKEpyro/IMG_2101.jpg

First I mixed the acids at below -10°C, then PE was added in small batches (most of the time ~1g of PE a time) while keeping temperature below 0°C. After adding all the PE I moved the beakers from salt/ice bath into warm water. Temperature of nitration mix was around 16°C I sustained this temperature for 30 minutes.
Here's the short video of stirring:
http://s242.photobucket.com/albums/ff11/NUKEpyro/?action=view&current=MVI_2105.flv

After that I warmed up the nitration mix with hot water to 30-43°C for around 25 minutes. After warming it up I noticed viscosity of nitration mix drastically dropped. I damped the nitration mixes in around 1.9L of cold distilled water I stirred the whole thing virgously to prevent decomposition of product. I decanted waste water and added fresh one few times then few times with 2% NaHCO3 sollution. And finaly few times with distilled water again.
The picture of percipitate ready to filter:
http://i242.photobucket.com/albums/ff11/NUKEpyro/IMG_2111.jpg

I filtered the product and let most of the water leak trough filtering paper. I collected the product and dissolved it in 400mL of boiling acetone with teaspoon of NaHCO3 dissolved in it mixture started to foam after it ''foamed out'' it was moved in hot water while stirring to distribute heat. I filtered it and damped the filtrate in NaHCO3 sollution in distilled water while stirring. I decanted most of the liquid, filtered the crystals and dried them for around 2 days on warm pipe 30-40°C.
The product with AA battery for comparison:
http://i242.photobucket.com/albums/ff11/NUKEpyro/Picture003.jpg

http://i242.photobucket.com/albums/ff11/NUKEpyro/Picture004.jpg
The yield was satisfying IIRC it was around 34g.
Few days later I attempted another synth it was another paralel nitration.
Materials used: 3x (20g of PE, 68mL of 65% HNO3 and 49.5mL of 96% H2SO4)
This time I used three 250mL beakers for stirring I used two thermomethers and glass rod.
I put the beakers in salt/ice bath, mixed the acids at below 5°C. I started adding PE in 1-2g a time while not letting temperature above 20°C. I was stirring constantly (as much as I coud stir 3 beakers). After adding all the PE I left beakers stand for around 10 minutes in room temperature water with occasional stirring.
http://i242.photobucket.com/albums/ff11/NUKEpyro/PETN120g004.jpg

I decided to move nitration mix from all three beakers to bigger 2L beaker (It woud be hard to control 3 beakers at once). After most of nitration mix was transferred into the large beaker nitration mix was warmed and kept on 45°C (+-1°C) for 30 minutes.
Nitration mix in 2L beaker at around 45°C
http://i242.photobucket.com/albums/ff11/NUKEpyro/PETN120g005.jpg
After heating it was damped in cold distilled water washed couple of times with distilled water and NaHCO3 sollution.
PETN ready to filter: http://i242.photobucket.com/albums/ff11/NUKEpyro/PETN120g.jpg

I filtered product and dissolved it in 500mL of hot acetone. Recrystalization was done similar way at the synth before acetone sollution was filtered and damped in 5L of distilled water with NaHCO3 dissolved in it. After damping it I decanted liquid and collected crystals on filtering paper.
The product yield was dissapointing around 70g from 60g of PE. I suspect the improper ratio of acids/PE and some of acetone sollution got spilled for souch a bad yield…

This is the product from both above mentioned synths 103.8g of recrystalized PETN:
http://i242.photobucket.com/albums/ff11/NUKEpyro/PETN1038g004.jpg
PETN flame test: http://rapidshare.de/files/40755178/PETN_flame_test.avi.html


Next thing I tried was a bit bigger nitration. I helped myself PE/acids ratios using some macro. I got those ratios by elevating ammounts of reactants.
That's the screenshot: http://shrani.si/f/19/pV/4FbmS5jp/petn-macro-2.png

Materials used: 100g of PE, 390mL of 65% HNO3, 255mL of 96% H2SO4
First I mixed the acids below 30°C in 2L wide neck beaker which was placed in salt/ice bath. Acid mixing took me couple of hours so as the addition of PE (2-4g a time) while keeping temperature below 10°C. After all PE has been added beaker was left in warm water at 15-20°C for around 50 minutes I occassionally stirred it. Fuming was very intense during the whole procedure and I coudn't stand HNO3 fumes so I used wet cloth as some form of respiratory protection. After 50 minutes beaker was moved in boiling water( water had 80-90°C) I was stirring virgously to prevent localized heating and moving beaker in and out of hot water bath untill I reached temperature of 45°C. I sustained that temperature for around 40 minutes then I damped the whole thing in 5-6L of water and washed it couple more times with distilled water and NaHCO3 sollution. At the end I decanted remaining liquid and filtered the product. After filtering I used some toilet paper to soak even more water from crude PETN.
Then it was dissolved in 1-1.3L of acetone. Acetone sollution was warmed up to it's boiling point and filtered - I managed to filter most of it but then filter paper clogged badly PETN started to recrystalize on it. I became tired of it knowing filtration woud take forever and product loss will be great(it will stay on wrong side of filter paper) so decided damp the rest in distilled water with NaHCO3 dissolved in it. Liquid was once again decanted and crystals collected on filtering paper.
I got 161.6 g of recrystalized and dry product.
Here are some pictures of synth (nitration and drying):
http://rapidshare.de/files/40755246/100g_PE_nitration.rar.html

And some pictures of dry PETN in 2 piles(265.4g total) smaller pile 103.8g larger pile 161.6g AA batery is placed inbetween as the scale:
http://i242.photobucket.com/albums/ff11/NUKEpyro/2654gofPETN004.jpg?t=1224932251
http://i242.photobucket.com/albums/ff11/NUKEpyro/2654gofPETN001.jpg?t=1224932252

About a month and a half later I detonated 20 grams of PETN/Al
Ratios(by weight of course):
94% PETN (18.8g)
6% Al (1.2g)
Around 0.4grams of HMTD packed in straw was used as a detonator. The charge was packed in plastic cube like box. The charge was put on asphalt.
Video:
http://www.youtube.com/watch?v=EvkAst3zqug
Camera was 15-18m away on some box.

Pictures:
http://i242.photobucket.com/albums/ff11/NUKEpyro/20gPETNAl006.jpg?t=1224933331
http://i242.photobucket.com/albums/ff11/NUKEpyro/20gPETNAl003.jpg?t=1224933334


Plastizicing PETN:

Ratios used:
83.6% PETN (~91,9g)
4.9% Motor oil (~5,4g)
11.5% PIB (~12.7g)
I used 110g of reactants but got only 103g of product (I guess the rest sticked to ''equipment'' I worked with).
Procedure:
PIB (in form of ratglue) was dissolved in around 50-80mL of diethyl ether, motor oil was added to sollution and finaly the PETN after motor oil dissolved. I homogenized the mixture with small wooden stick and I let the solvent evaporate on hot water bath outside.
103g of PETN/PIB/Motor oil
http://i242.photobucket.com/albums/ff11/NUKEpyro/103gramsofPETN-PIB002.jpg?t=1224935426
Video showing mechanical properties of ''plastique'':
http://rapidshare.de/files/40756625/103_grams_of_PETN-PIB.avi.html
It was packed in shaped charge a month after manufacture.
Dimensions:
Liner : 50mm spherical shaped glass (lightbulb)
Standoff: 125mm from top of the liner
Some pictures of it:
http://i242.photobucket.com/albums/ff11/NUKEpyro/Glassshapedcharge005.jpg?t=1224936012
http://i242.photobucket.com/albums/ff11/NUKEpyro/Glassshapedcharge010.jpg?t=1224936013
http://i242.photobucket.com/albums/ff11/NUKEpyro/Glassshapedcharge013.jpg?t=1224936014
Unfortunatelly glass broke right before detonation and I detonated it anyway. Here's the detonation video:
http://www.youtube.com/watch?v=TUnMvlJ8plc
And consiquences: Concrete block SC was on got completely shattered other two got moved by the force of blast:
http://i242.photobucket.com/albums/ff11/NUKEpyro/SCfailure007.jpg?t=1224937121
http://i242.photobucket.com/albums/ff11/NUKEpyro/SCfailure006.jpg?t=1224937122
http://i242.photobucket.com/albums/ff11/NUKEpyro/SCfailure004.jpg?t=1224937123


I had another PETN/Al test:
Ratios used:
36.5g of PETN
2.4g of Al powder(german dark)
Charge was placed on carhood.
No video this time(there is one but I don't want to upload it because of some reason)
There's a picture instead:
http://shrani.si/f/3j/Pd/1oHsf7UL/img7728petn.jpg
It was recorded with my friend's camera(open objective with 20s expousure). It's almost better than a video.
Results - pictures:
http://i242.photobucket.com/albums/ff11/NUKEpyro/3112016.jpg?t=1224937274
http://i242.photobucket.com/albums/ff11/NUKEpyro/3112011.jpg?t=1224937274
http://i242.photobucket.com/albums/ff11/NUKEpyro/3112009.jpg?t=1224937275


Approx 3 months later I plasticized some more PETN:
Ratios used:
65g PETN
4.7g PIB
3.1g Motor oil

Procedure (with pictures):
http://i242.photobucket.com/albums/ff11/NUKEpyro/plastique001.jpg?t=1224937838
First 3.1g of motor oil was added on ceramic plate.
http://i242.photobucket.com/albums/ff11/NUKEpyro/plastique002.jpg?t=1224937839
4.7g of PIB on paper was put on motor oil.
http://i242.photobucket.com/albums/ff11/NUKEpyro/plastique003.jpg?t=1224937839
65g of PETN was weighted for purpouse of plasticizing.
http://i242.photobucket.com/albums/ff11/NUKEpyro/plastique004.jpg?t=1224937841
3.5g of PETN was weighterd for the use in booster.
http://i242.photobucket.com/albums/ff11/NUKEpyro/plastique005.jpg?t=1224937840
Diethyl ether was added to 4.7g PIB and 3.1g motor oil and stirred with small wooden stick.
http://i242.photobucket.com/albums/ff11/NUKEpyro/plastique006.jpg?t=1224937848
PETN was added to PIB/Motor oil sollution in diethyl ether.
http://i242.photobucket.com/albums/ff11/NUKEpyro/plastique007.jpg?t=1224937849
Everything above mentioned was stirred.
http://i242.photobucket.com/albums/ff11/NUKEpyro/plastique008.jpg?t=1224937869
The dish with materials was put on hot water bath to let solvent (diethyl ether) evaporate.
http://i242.photobucket.com/albums/ff11/NUKEpyro/plastique009.jpg?t=1224937872
This is the final product…

Around 6 months later…
http://i242.photobucket.com/albums/ff11/NUKEpyro/plastique.jpg?t=1224938269
Pressed plastic explosive with hole for booster/detonator in middle, Electric detonator, 3.5g of PETN is on paper, and 7g HMTD in plastic bottle.
The charge was put on few kilograms of bricks and detonated using electrical ignition.

Detonation video:
http://www.youtube.com/watch?v=K93YWRtZRdQ

Consiquences:
http://i242.photobucket.com/albums/ff11/NUKEpyro/Plastique013.jpg?t=1224938279
http://i242.photobucket.com/albums/ff11/NUKEpyro/Plastique011.jpg?t=1224938280
http://i242.photobucket.com/albums/ff11/NUKEpyro/Plastique010.jpg?t=1224938281
This test showed the good shelf life of PETN (it was prepared almost year before blast) and plastic explosive's shelf life(around half a year old). I noticed only some change in mechanical properties of plasticized PETN and smell change(that's one of the reasons it was detonated).


Around a week ago I sucessfully nitrated some more PETN:

Ratios used:
100g PE
390mL 65% HNO3
255mL 96% H2SO4
Procedure:
Both acids were mixed in 1L erlenmeyer flask (may the 2L beaker rest in peace) in salt/ice bath. Temperature when mixing acids was never let above 25°C. Mixing acids took me around 1h 20 min this time I used real gasmask (M40 with NATO filters) not some wet cloth. After mixing acids I let the temperature drop to around -15°C and started adding PE. First I added it in 4-6g ammounts later it was being added in 6-15g ammounts. I never let the temperature rise above 10°C when adding PE(that wasn't that hard because it was cold outside and salt/ice bath was working great). Addition of PE took me around 2 hours. After addition I put the erlenmeyer flask with precursors in warm water temperature of nitration mix has risen to 26°C I left it there for about an hour with occassional stirring. When I moved it out of water temperature dropped to 14°C. I heated liter or two of water to it's boiling point, and immersed erlenmeyer flask with nitration mix into it while constantly stirring to reduce the chance of experiencing runaway nitration.
Here's the picture of mixture being nitrated:
http://i242.photobucket.com/albums/ff11/NUKEpyro/PETNII001.jpg?t=1224940278
Mixture was heated on 45°C(with 2°C deviation). Like always there have been alot of nitric acid fumes. After around 35 minutes the nitration mixture was damped in 6L of normal water, decanted, washed with some more water, decanded again and finaly washed with distilled water. I didn't neutralized it to this point. After it partially dried I sucked as much water as I coud with toilet paper, added some diethyl ether to dry it a bit further. Next day I dissolved it in total 1L of acetone. I split acetone into 2 parts (2x500mL) because I didn't have proper 2L glass vessel.
After putting ~half of PETN in 500mL of acetone inside 1L erlenmeyer flask:
http://i242.photobucket.com/albums/ff11/NUKEpyro/PETNII005.jpg?t=1224941979

Improvised ''filtration device'' (there's around 5L of NaHCO3 sollution in the bucket below):
http://i242.photobucket.com/albums/ff11/NUKEpyro/PETNII008.jpg?t=1224941983
Heating PETN/acetone sollution neutralized with NaHCO3 in erlenmeyer flask in hot water bath(70-80°C):
http://i242.photobucket.com/albums/ff11/NUKEpyro/PETNII009.jpg?t=1224941984
PETN/acetone sollution (with great excess of NaHCO3 on bottom) at it's boiling point(56-58°C):
http://i242.photobucket.com/albums/ff11/NUKEpyro/PETNII010.jpg?t=1224941984
Same purification procedure was done 2 times I used dense cloth as filter because I didn't want to clog filter like the last time… I was constantly stirring water below when filtering PETN sollution.
After all acetone/PETN sollution was filtered:
http://i242.photobucket.com/albums/ff11/NUKEpyro/PETNII011.jpg?t=1224942804
Like most times before I decanted most of liquid PETN percitipated in. <2mm needles formed which broke down into smaller crystals after filtering the product.
Here are pictures of filtered still wet PETN:
http://i242.photobucket.com/albums/ff11/NUKEpyro/PETNII012.jpg?t=1224943571
http://i242.photobucket.com/albums/ff11/NUKEpyro/PETNII014.jpg?t=1224943585
Drying PETN:
Still wet:
http://i242.photobucket.com/albums/ff11/NUKEpyro/PETNII.jpg?t=1224943912
Partially dried (after 7h on 30-40*C):
http://i242.photobucket.com/albums/ff11/NUKEpyro/PETNII015.jpg?t=1225067678

It took PETN around 27hours to completly dry here are some pictures (AA battery for scale):
http://i242.photobucket.com/albums/ff11/NUKEpyro/PETNII016.jpg?t=1224944046
http://i242.photobucket.com/albums/ff11/NUKEpyro/PETNII019.jpg?t=1224944047
Dry product weight is 159.7g this time.

Notes and comments and improvements suggestions:
At first few synths I was probably being almost too careful(mixing acids at below -10°C etc, adding PE below 0°C etc.). Most recent PETN synthesis I preformed was a bit modified because of lack of resources(money,distilled water,NaHCO3 acetone…). I think important contributing factor to lower yields in synthesis was not dilluting PETN/acetone sollution enough and some of PETN stayed dissolved in the decanted liquid. I will try to improve that by using 10 times as much distilled water as acetone when recrystalizing the product next time. I hope that's the main cause for lower yields than expected anybody else thinks the same?

After six and a half hours of writing this post I hope it will be useful to somebody.

A fantastic post!

You really know your shit and when I finally decide to join the PETN club, you will be getting a PM from me!

Keep up the good work man :)

Seconded. Great work.

That powder looks deliciously pure and fluffy, but dense and brisant at the same time.:p There's no feeling quite like having a few hundred grams of an excellent secondary waiting at home for you, is there?

Unfortunately, I don't have much input on the subject. As like others here, I have no idea where I'd get pentaerythritol to try this synthesis myself, not that I've looked.
Welcome to the forum. I look forward to hearing more from you.

One last thing: You may want to avoid doing nitrations in areas where small children hang out. Just a thought.

NUKE(slo) - Let me take the time to congratulate you on your fantastic post. That is what we like to see here on RS.org. Batteries/phones used as scales, no faces, documentation of processes with temperatures and times, etc.

Keep up the good work. There is nothing like having that power at your fingertips and not having to worry TOO MUCH about blowing your fingers off. I love the det tests.

Just a little thing, try testing your PETN against something a little more sturdy. While absolutely destruction is excellent, to get a true measure of power try going a little less all out.

Also, in your very first image I don't see a bucket/container to crash your product in if you get a run away. It is VITALLY important to have such a thing very close at hand. Even a few meters away is too far, because it takes about 2-3 seconds for a nitration to go from 30ºC to boiling over. Over you, over your clothes, over your table, over your dog, over your tiles, over your pants.... Really, it is horror.

So keep a 30-40L bucket mostly filled with water and a hose attached to running water if you can.

Good job pretty much.

Nuke: I re-Read it again and it looks so much better where it belongs: on the forum rather than as a .txt on my screen. I hope I didnt miss anything in my quick proofread and by the look of it I didnt. A good test is to strap 10 grams to a 3mm aluminum witness plate and see how large a dent you make :D or if you can make a lead block maybe the trazul test.

Anyway thats all the tests I can think of, has anyone any other ideas for tests? Maybe try make detcord next? My pentaErythritol should be here before christmas if things go Well.

Also, I found a MSDS for a #8 blasting cap, and will attach once I am on a computer. It contains 750 milligrams of PETN. The initiator is 250 milligrams of lead azide so maybe we could try to replicate it?

Also, is the relative effectiveness of PETN 180%, assuming TNT as 100%? Is that based on the trazul test? If so, that makes my tests easier to perform.

Well done, you added a ocean of information :D

Last week SWIM did a parallel nitration also, to compare home boiled H2SO4 and some fresh 98%, its hard to stir both the same time with your hands :p

Ice bath without salt added.
Both were with home boiled HNO3 >65%
Powerlabs synthesis also.
Raising temp on the 98% H2SO4 synth causes NOX buildup, so SWIM didn't do the last warming step.
Temp fluctuated between 3 & 4 degrees, small additions.

From 20 grams of PE SWIM got 43 grams PETN with 98%, and 36 grams from my home boiled acid, so that sucks allot. SWIM am quenching the spend acid anyway.
The H2SO4 was boiled over 300 g and under a blanket of dry air.

Indeed the PETN should be tested against a far more sturdy target and its true power and brisance will only ever be realized at high density... a density that is only achievable with this fantastic explosive.

In short I feel that if you are going to detonate PETN then you simply MUST do it at density, else why bother to go to the hassle of making it, may as well stick with ETN!

If I was a member of the PETN club I would be firing off small charges. Film canister sized with pressed PETN against steel plate targets. I have read that the addition of 20% Nitroglycerin increases shattering power. You could even blend the ester with 10% montan wax which would make pressing to high densities easier and safer. Go for at least 1.5-1.6g/cc

... just a few thoughts

Also, is the relative effectiveness of PETN 180%, assuming TNT as 100%? Is that based on the trazul test? If so, that makes my tests easier to perform.

There may be more than one way of determining this percentage, but I am certain of one way. It is a formula that involves mols of gas evolved, the amount of heat created, detonation velocity, and density. I can't recall the formula off the top of my head, but I have it listed in an ETN thread in the HE section here (http://www.roguesci.org/theforum/showthread.php?t=5675). My post is about half way through the thread. With this formula I think ETN came out to be 134% that of TNT, and PETN came out to 143%. ETN lost out primarily because of its significantly lower gas production.

Again, some percentages may be concluded from the Trauzl test, which I think would be more accurate. The way I am talking about is really only good for a theoretical calculation that looks good on paper.

Frank: You make an excellent point about the importance of density. Here is a quote from the same post I have mentioned about about PETN.

Vp1 = Vp2 +3500 (p1 - p2)
V 1 and 2 are the VoDs for densities p 1 and 2 respectively. 3500 is a constant.

Lets try PETN for example. VoD of 8400 m/sec at max density of 1.77 g/cm3. A density of this amount could probably only be reached through professional means (eg hydrolic press). So lets see what happens when the home chemist presses his to 1.2 g/cm3

8400 = x +3500 (1.77 - 1.2)

8400 = x + 1995
x = 8400 -1995 = 6405 m/sec

That loss of just .57 g/cm3 resulted an approximate 2,000 m/sec decrease in VoD. This is a good example of how a loss in density will greatly lower your explosives performance. If you're not pressing your PETN, like Frank said, you might as well save your PE and stick with ETN. That addition of NG will not only increase the power and OB, as PETN is OB -, but it will also help you achieve a higher density. Just have to be a little more careful when handling is all ;)

That loss of just .57 g/cm3 resulted an approximate 2,000 m/sec decrease in VoD. This is a good example of how a loss in density will greatly lower your explosives performance.


Plus remember that detonation pressure (kbar) and therefore shattering power is proportional to the density (g/cm3) but also the SQUARE of the VoD (m/s)...

Detonation pressure is 2.5 times density times VoD squared, all divided by 1,000,000.

In the case above the difference between 123kbar and 312kbar speaks for itself!

Okay, my stuff came in, and I was looking at the Certificates of Analysis for each grade sent. The Monopentaerythritol, both straight and 200 mesh, came in at 99% Mono-PE, while the straight tech grade and the 200 mesh tech came in at 90 and 89% respectively. On their website, they stated that most of the non-mono remainder is Poly-PE, which I would assume to mean is bonded somehow. Covalent? Ionic? I guess I'll have to call 'em and ask. Lucky for me I have a couple of legit uses for it. One is for a client that builds stringed musical instruments that are VERY top-end, the "cheapest" guitar going for over $3K. He's having a little trouble the finish, and these are the very problems that PE can cure. Also, PE can add intumescent properties to coatings. One subject that is very near & dear to my heart is the subject of aircraft fire safety. Back in the '90s, I lost a test pilot, a cousin, and a dear friend, all within a couple of years, and all to aircraft fires (two inflight & one post crash). Ever since, I've been investigating ways to mitigate the effects of these catastrophes, at least enough to buy a few minutes to either land or jump for it.

Regarding the Poly-PE, obviously I can't ask the manufacturer if it will interfere with production of PETN, or otherwise endanger the lab, its surroundings and, most importantly, its occupants. Anybody know of any papers on the subject, or if it's even a concern?

Whaddaya' think?

I think thats an awesome find. I'm jealous.
Well, whem I get some spare money it is time to order some PE and nitric, separate of cource.

I finally decided to make a bit of PETN. I got an 83% yield. I did lose some in the decanting, and when I screened the original PE through a 60 mesh screen. I will have to do another run and weigh after I screen the PE, and be more vigilant saving the product.

Anyways, I used double distilled 98 - 99% HNO3 and 10 grams of PE.

I cooled the nitric to 0 degrees, and slowly added the PE keeping the temp below 15 with stirring. It took about 14 minutes to add the PE. After addition I let it sit with occasional stirring for 20 more mins. the final temp was 18 degrees.

I dumped it into 500 ml of distilled water, let it sit and decanted. I did this twice, then neutralized with bicarbonate of soda. I tested PH at 7. I filtered it and washed it.

Next I let it dry and got 20.32 grams of crude PETN. Although I think it was pretty pure.

I dissolved it into acetone to recrystallize it. My 20 grams didn't dissolve in 50 ml of warm acetone. I added 20 more ml and it all dissolved easily.

The PH was tested at 2, the bicarb didn't help at all. I had no ammonia that was without surfactants so I didn't use that.

I added 120 ml distilled water with 1 gram bicarb slowly to the solution of ace\petn. I got a cubical, a bit smaller then table salt crystals of PETN. Its so pretty! The PH was tested again at 7.

I ended up with 19.27 recrystallized PETN.

So, How can i improve my yields? Longer time in the acid? Higher temp?

Thanks

I was just hit by what may or may not be a good idea. You put Hexamine with H2O2, you get HMTD. Put Hexamine with HNO3, you get RDX. Put Pentaerythritol with HNO3, you get PETN. So what do you suppose would result from trying PE with H2O2?

I've got plenty of both, but I'm not sure I have the balls to try it. Anybody else ever attempt this? Still got your fingers?

Whaddaya' think?

Hexamine is a caged amine. And pentaerythritol not even a little related. I doubt much would happen when PE is mixed with H2O2... I could be wrong though. It would be pretty easy to test if you wanted to find out for sure..

From old mate wikipedia:

It can be prepared by condensation of acetaldehyde and formaldehyde in a basic environment.[2] The process occurs by successive aldol reactions followed by a Cannizzaro reaction. Impurities include dipentaerythritol and tripentaerythritol.[3]

Sources are as such:

http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=CV1P0425

To a suspension of 800 g. of paraformaldehyde (corresponding to 26.7 moles of formaldehyde) (Note 1) in 5.5 l. of water containing 210 g. (4.77 moles) of acetaldehyde there is added 180 g. (3.22 moles) of powdered quicklime in small portions with vigorous mechanical stirring (Note 2). The rate of addition is so adjusted that the temperature rises to 50° in thirty minutes, and during the subsequent additions the temperature of the mixture is not allowed to exceed 55°. The mixture takes on a slightly yellow color. After the addition is complete, stirring is continued for three hours, the mixture is filtered by gravity, and the yellow filtrate is acidified with just enough dilute hydrochloric acid to give an acid reaction to litmus. Subsequent to the addition of 30 g. of Norite and stirring for five minutes, the solution is again filtered.

The filtrate, which should be colorless, is concentrated on the steam bath under reduced pressure (Fig. 23) (Note 3) until crystalline material begins to separate. The liquor, amounting to approximately 3 l., is heated on the steam bath at atmospheric pressure and filtered with suction while hot, any crystals remaining on the filter being washed through by aspiration of wet steam. The filtrate is allowed to stand in the refrigerator overnight and the first crop of crystals filtered off. This weighs approximately 300 g. and melts at about 237° (corr.). The mother liquor is concentrated to approximately 2 l. and a second crop obtained as above; this weighs 60–70 g. and melts at 242° (corr.). A third crop of 50–60 g. melting at 249° (corr.) is obtained by concentrating the mother liquor to 1.2 l. The mother liquor is finally concentrated to a sirup, when a fourth crop weighing about 10 g. and melting at 248° (corr.) is obtained.

The combined product, weighing 410-420 g., is recrystallized from an equal weight of hot water containing 10 cc. of concentrated hydrochloric acid. The color is removed by the addition of 5 g. of Norite. By suitably concentrating the mother liquors, second, third, and fourth crops may be obtained, all of which appear to be of the same purity as the first crop. The total yield is 360–370 g. (55-57 per cent of the theoretical amount) of a product melting at 258–260° (corr.) and containing negligible amounts of calcium (Note 4). The final residue, amounting to 20–30 g., leaves a considerable quantity of ash on ignition.

The second link goes to a journal article (attached here).

al93535

Well done on that by the way, sounds like it went well. Don't to moan about the yield though, try making RDX and then see how dissapointed you will be will the yield. Almost 20 grams of pure PETN from 10 grams of PE is not shabby at all. I'm not saying that there aren't ways to improve on this, but definately not to be sniffed at.

I haven't had the pleasure of making any PETN yet, so I wouldn't know on how to improve on this. Maybe letting it sit for longer (with stirring) after the final addition may prove beneficial. Maybe not. Probably best to just have a play about and find out which route you find the best.

Alexires

Yes that is a good procedure that, as long as you can get hold of Acetaldehyde (Which some of us have just an equal struggle as obtaining PE itself). Of course making Acetaldehyde is always an option, and there is a nice procedure on this very site. http://www.roguesci.org/megalomania/synth/synthesis1.html

Uses (typically) Sodium dichromate, and a few other common chems. Sodium dichromate being quite expensive for some people to buy and a known carcinogen. I don't know.... the fun just never stops.

Fluoroantimonic, I was thinking more along the lines of rotating the PE into an isomer of some sort. There are four Hydroxyl groups, a couple of Carbons, and a couple more Hydrogens. With my luck, I'd probably wind up with something like Dimeric AP.

I've got plenty of PE, plus a gallon of 35% H2O2, so I guess I'll just have to grit my teeth and expend a little (VERY little) to see what happens. Maybe come up with a good Oxidizer. (A roll of the drums, please.)

While you're at it you might try a few different catalysts.. Just in like 0.5g batches, you won't waste much and there shouldn't be much danger in case of unstable products.

Yeah, I was thinking about a weak acid for starters. Maybe Citric.

Ok, let's get back to the topic shall we?

About a week and a half ago I carried out another nitration of PE.

Ratios used:
100g PE
390mL 65% HNO3
255mL 96% H2SO4

First acids were mixed in 1L erlenmeyer flask immersed in ice/salt bath I didn't let the temperature rise above 25*C. Mixing took me around 1h (A lot faster than previous times) ice/salt bath was being overkill again… At the end of mixing I added ~150mL of 65% HNO3 to rest of acids and temperature rised for only 7 °C.
Mixing acids:
http://i242.photobucket.com/albums/ff11/NUKEpyro/PETNII026.jpg?t=1226137048
After acids were mixed 100g of PE was weighted and added 6-15g a time.
100g of PE:
http://i242.photobucket.com/albums/ff11/NUKEpyro/PETNII027.jpg?t=1226137441
Temperature between adition of PE was never allowed to rise above 20°C. It took me 1 hour and a half to add all the PE to acids. After all PE has been added I left it at 10-15°C for 1h.
After adding all the PE:
http://i242.photobucket.com/albums/ff11/NUKEpyro/PETNII028.jpg?t=1226141674
I smelled some NO2 vapors, noticed the slight colour change above nitration mix and small bubbles in nitration mixture temperature was normal but NO2 even in small ammount bothered me. I decided to heat the mixtue anyway it was heated to 43-45°C for 20 minutes then I coudn't tolerate NO2 formation anymore and damped it in 5L of cold water. I decanted the liquid, washed it with water again I repeated the whole washing process few times and let it stand under small ammount of water overnight. In the morning I filtered the crystals and washed them few times with water.
Filtration process:
http://i242.photobucket.com/albums/ff11/NUKEpyro/PETNII029.jpg?t=1226141688
Crystals that were collected on filtering paper were transfered in some plastic vessel split in half and each half was dissolved in 500mL of hot acetone with few grams of NaHCO3 added and filtered trough some dense clothing in 10L of cold low % NaHCO3 sollution (~6-8g of NaHCO3 dissolved in ~10L distilled water). After damping both halves of acetone/PETN sollution crystals were left to sit for 30 minutes and liquid above crystals was decanted. PETN crystsals were filtered and dried for ~25 hours at 30-40°C.
Dry PETN crystals:
http://i242.photobucket.com/albums/ff11/NUKEpyro/PETNII030.jpg?t=1226142426
Dry product weighted 160.7g. I combined both PETN piles together into massive ''superpile'' which weighted 320.5g.
Here are some picture of it (it's on A3 paper with AA battery for scale):
http://i242.photobucket.com/albums/ff11/NUKEpyro/PETNII020.jpg?t=1226142650
http://i242.photobucket.com/albums/ff11/NUKEpyro/PETNII021.jpg?t=1226142649
http://i242.photobucket.com/albums/ff11/NUKEpyro/PETNII023.jpg?t=1226142648



Yesterday the whole pile was plasticized using PIB and motor oil.

Ratios used:
320.5g of PETN (plastic vessel weights 40.9g)
http://i242.photobucket.com/albums/ff11/NUKEpyro/PlastiqueIII001.jpg?t=1226142793
15.4g of motor oil
http://i242.photobucket.com/albums/ff11/NUKEpyro/PlastiqueIII002.jpg?t=1226142794
And 23.6g of PIB.


First PETN was put in glass bowl:
http://i242.photobucket.com/albums/ff11/NUKEpyro/PlastiqueIII003.jpg?t=1226142792
15.4g of motor oil was weighted in 100mL glass beaker, PIB was weighted on paper and paper (together with PIB) was moved into the beaker containing motor oil. PETN in glass bowl was then wettened with around 50mL diethyl ether and mixed. Some diethyl ether was poured in glass beaker containing PIB and motor oil mixed and moved from beaker to glass bowl containing PETN wettened with diethyl ether. Beaker was washed couple of times with diethyl ether to remove most of PIB and motor oil from it. Ingredients in glass bowl were mixed with hands for 1 hour and 10 minutes outside. All the diethyl ether evaporated so no additional heating was required.


Plastique pressed in plastic vessel:
http://i242.photobucket.com/albums/ff11/NUKEpyro/PlastiqueIII004.jpg?t=1226144746
http://i242.photobucket.com/albums/ff11/NUKEpyro/PlastiqueIII005.jpg?t=1226144747


After few additional hours of ''mechanical work'' plastique looks like that and weights 354g (AA battery for scale):
http://i242.photobucket.com/albums/ff11/NUKEpyro/PlastiqueIII006.jpg?t=1226144747
http://i242.photobucket.com/albums/ff11/NUKEpyro/PlastiqueIII007.jpg?t=1226144748
http://i242.photobucket.com/albums/ff11/NUKEpyro/PlastiqueIII008.jpg?t=1226144749
http://i242.photobucket.com/albums/ff11/NUKEpyro/PlastiqueIII009.jpg?t=1226144749
http://i242.photobucket.com/albums/ff11/NUKEpyro/PlastiqueIII010.jpg?t=1226144750
http://i242.photobucket.com/albums/ff11/NUKEpyro/PlastiqueIII011.jpg?t=1226144750
http://i242.photobucket.com/albums/ff11/NUKEpyro/PlastiqueIII012.jpg?t=1226144751

I'm hoping to use it (together with ''few'' extra grams which will hopefully be produced in near future) in 84mm copper lined conical shaped charge.
The only obstacle now it money (copper is so expensive…).
If I manage to get proper sized copper rod liner dimensions will be following:
2r = 84mm
Inner angles: 60°
Thickness: 2-4mm



Does anyone have any ideas what coud be the ''plan B'' use for it if I woudn't be able to get liner as planned for it?

Does anyone have any ideas what coud be the ''plan B'' use for it if I woudn't be able to get liner as planned for it?

Well what ever you do decide to do with this beautiful lump of death, first you must do an accurate pressed density measurement.

On drying it appears that your proportion of prasticizer, PIB and residual ether accounts for around 12% by mass which is right about where it should be in a high quality PETN based plastique.

This "mechanical work" that you speak of is crucial in order to create a cohierent mass with that small a portion of plasticizer. Would you mind elaborating on this technique? Do you merely roll your plastique under a heavy weight to shave the crystals against each other and remove unwanted air? If you did it this way a few grams at a time it must have taken an age!

With that quantity of plastique at your disposal you simply must explore some DISCREET old fashioned criminal damage :) 50 gram ball pressed on to steel fence, railing etc... you get the idea!

As for shaped charges, remember that steel also has good performance but if you are set on using coper and don' mind coughing up some dollar, Copper Tundishes make great liners if you can find one the right size.

Keep us posted and don't forget that accurate density measurement. Weigh a small cup with and without water then press in that dough. you know the way!

Uh, Frank, what the Hell's a tundish? Sounds like something a Victorian spinster would use in private.

And NUKE(slo), as for your troubles concerning the Copper cone, why not round up a sheet of Copper Foil, cut it up and stack it? What I mean is, make a paper pattern of a 60 degree cone with about 3/8" (9mm) overlap, cut out a bunch of Copper blanks per the pattern, stack 'em & tack 'em with a spot welder, roll the stack into a cone, and spot weld the overlap. I seriously doubt that the PETN will care whether or not the copper is solid or stacked. If you're worried about the greater thickness at the overlap, not to worry. Just tack the layers far enough away from the edges that you can interleaf them at the edges, having cut away every other layer in the overlap so that the thickness remains consistant. Personally, I doubt if it will make a damned bit of difference, but if it does, that should cure it.

Uh, Frank, what the Hell's a tundish? Sounds like something a Victorian spinster would use in private.

And NUKE(slo), as for your troubles concerning the Copper cone, why not round up a sheet of Copper Foil, cut it up and stack it? What I mean is, make a paper pattern of a 60 degree cone with about 3/8" (9mm) overlap, cut out a bunch of Copper blanks per the pattern, stack 'em & tack 'em with a spot welder, roll the stack into a cone, and spot weld the overlap. I seriously doubt that the PETN will care whether or not the copper is solid or stacked. If you're worried about the greater thickness at the overlap, not to worry. Just tack the layers far enough away from the edges that you can interleaf them at the edges, having cut away every other layer in the overlap so that the thickness remains consistant. Personally, I doubt if it will make a damned bit of difference, but if it does, that should cure it.

PETN deserves a lathe spun copper cone, NO LESS.

Save the wrapped welded cowboy endeavours for kewl APAN filler charges or if you want decent penetration through say... wood!

As for the air gap, sure the PETN doesn't care a shit but when that cone "collapses" all you will create is a copper spray and you will be lucky to achieve 1CD of penetration and I can get that with ETN and a steel measuring spoon!

Get a spun liner. Even the Al top from a cheap wax lamp or a carfully sawn off glass candle bulb!

Also, now that I remember, you should save 50 grams of that PETN to investigate crystal shapes. Your holy grail is small equidimensional cubic/spherical crystals. Try different solvents, fast and slow procedures, hot, cold and with clashes in temperature. I have heard that ethyl acetate could be a good place to start. If you can achieve this then you are well on your way to making pliable yet DENSE plastique with performance that is second to none :)

...whats a Tundish? Wiki and eBay is your friend!

I have been reading that PETN can be initiated with as little as .1 gram of double salts.

I just tried a detonator with pressed PETN, 1 gram, in an aluminum tube, 1/4" ID 3/8" OD. On top of that I placed .15 grams of double salts and pressed them. Next I added .15 grams of 4fa BP and fused it, sealed it and epoxied the end.

The DS went off but it just scattered the PETN. In fact some is still pressed in the tube I found!

So I decided to go for broke and made another and added .45 grams of double salts on top. With the same result as before.

I am pressing these rather hard in a 4 ton press. I am putting about 30-40 lbs on the lever, and at 26:1 there is 780 to 1040 lbs on the 1/4" dowel.

Any suggestions? Thanks guys!

So far as I am aware, PETN cannot be initiated straight with DS at any density, its not quite sensitive enough or DS ain't quite up to the job. You should use a 50/50 co-precipitate of PETN with sodium azide, 100mg of this between your base and primary. With this set up you will have far more luck :)

EDIT: you could even replace that mix with 50mg ETN but I am not even sure this would be reliable, plus you are introducing a less chemically stable factor into the deal... rather like using HMTD.

Well.. actually yes its possible, I’ve detonated RDX with double salts before, with less than 100 mg of it, PETN with 50 mg.
The PETN/RDX must have an low density, it will become more sensitive that way ,but it isn’t brisant, you have to pack multiple densities in your detonator to ensure ignition of the whole train.

If you want the whole blasting cap pressed, you have to go for another primary.

You have to find a way to press the Double salts and not the PETN witch is in contact with it, just to give the double salts its highest performance.
It’s also recommended to make the DS as clean as possible with very little impurities, It has an great variation in it’s properties when it has little contamination’s, an good indicator is the end products color.

Like was mentioned, the PETN would have to be at a lower density, decreasing its power unless you use more DS. PETN isn't worth the trouble if you're not pressing it to maximize performance. Or you could add some ETN in contact with the DS which will probably detonate as it is a bit more sensitive. That kind of defeats the purpose of going through the trouble to make PETN. Why not just use HMTD or another primary instead?

So I guess they left out that the PETN was basically not pressed when used with double salts. Oh well, I learned something new. Thanks for the help.

How about mercury fulminate? Has anyone had any experience with it setting off PETN? It's VOD is 5km/s at higher densities, and it produces gas so I think its a better choice.

EDIT: I just ordered 100 grams of triple distilled Mercury so we will see how it performs!

/\
I had plans to fool around with MF for use in detonators not long ago. I gave up on producing it due to possible impurities in my mercury, the toxic/flammable gases produced in the synthesis, the relatively high sensitivity of the compound, and the environmentally toxic wastes produced.

I still do wonder about the merit of MF, so I'll be interested to read your reports. :)

@ Deceitful Frank: How and why would you make a coprecipitate of sodium azide and PETN? If what you really mean is lead azide and PETN, then I understand what you mean but AFAIK, straight lead azide is just as good.

To anyone who might be looking for a good primary and wants to avoid the sensitivity of the peroxides: First you must obtain some nitrite. In some parts of the world you can just buy it (lucky bastards). Otherwise it can be synthesized by absorbing NOx mixtures in alkali solutions or by reduction of nitrates.
Once you have a source of nitrite, you can pretty much take your pick of primary. Rosco's azo-chlathrate is a good candidate as is cobalt nitrotetrazolate or coprecipitated lead azide and lead styphnate in various proportions.

Microtek,

I have been doing a little bit of reading on azo-chlathrate. I have searched on here a bit, but I still don't understand what it is. I am assuming it is more then just one explosive.

I have 4-5 lbs of sodium nitrite, and can get plenty more. But I do not yet have any azide. Can you explain a bit more to me, or point me to the right thread? Or perhaps a PM would be best.

I found excellent information on the initiation of PETN with mercury fulminate. COAPE page 441, it explained all I needed to know. It looks like a good candidate for my purpose.

However, I am always looking to better my primary, and would like to know more about azo-chlathrate's.

And Lewis, I will report all of my testing, with pictures.

Help concerning PE synth.

I had just measured out the acids, 35.5mL of Nitric acid (62%) and 25.5mL of Sulfuric acid. The acids were mixed. Heat was evolved (for obvious reasons.) The mixture, was now re-cold. It had a temperature of -18.C
After that, I started to add ten grams of PE.
It was now that something did go wrong. First, I added 1 grams at a time, BUT the PE didn´t stay insoluble, it just dissolved directly! Astonished by this, I continued to add PE, but it still stayed soluble in nitrating-mixture.

The mixture had an continues temperature for -15.C, sometimes up in -10.C.
I think that it depends on the water-content in the NA, but the sulfuric acid should take care of it, should it not?

The H2SO4 has a conc. of 96% and the HNO3 has an 62%.

+++++++++++++
I edited your post and cut out the "in my dream" bullshit, its annoying. By popular vote we will decide if you get banned or not. - totenkov

Frank, Re your reply on post #634, I just don't see how the solidity of the cone could make that much difference. It occurs to me that it would be more a matter of configuration and proximity. As a matter of fact, I don't see any reason why a layer of metal powder, held in the same position/configuration as a solid cone, wouldn't work as well. Especially when one considers that powder metals can be consolidated with explosives, such as the selective shrapnel dispersion that's being worked with as we speak. (I saw a General, A FUCKING GENERAL, giggle like a schoolgirl when he saw a witness plate get perforated with a "smiley face" pattern. Those penetrators were launched in powder form, solidifying upon detonation initiated by a proximity fuze.)

So I feel comfortable in betting you a top flight dinner at the overpriced dump of your choice that there would be no practical difference between the performance of a solid, machined copper cone, or one built up out of stacks of copper foil, as long as the mass & geometry were close.

So I feel comfortable in betting you a top flight dinner at the overpriced dump of your choice that there would be no practical difference between the performance of a solid, machined copper cone, or one built up out of stacks of copper foil, as long as the mass & geometry were close.

I don't know how you are going to get the mass and density close enough unless you use a solid cone. Powders would work but I doubt you could get the density close enough, unless you have some groovy equipment like the US Military.

I don't if it would work or not, but you might be able to get some good density by saturating molten tin, lead, bismuth, etc with copper powder. That should achieve a high density and still a high copper content. It would be interesting to test at least.

Still, I don't know if the density makes huge difference.. after all, IIRC aluminum and glass liners work as good or better than lead liners...

By mixing multiple grades of powder and maybe using a hydrolic press, I bet you could get a pretty nice liner.

In my opinion any non-lathed liners are very attractive and worth pursueing even if the max penetration is reduced slightly.

I more meant you would need to get the powder of whatever metal you are using to approach the density of the solid metal version.

Less copper = less penetration, that is all I am getting at.

Well, in the case of the foill stacks, I imagine the thickness would be limited by the ability of the spot welder to penetrate. As for powder, it takes remarkably little pressure to consilidate a part out of it. I doubt if very many of us has a CIPing or HIPing 'clave in the garage, but for something as relatively soft as Cu a hydraulic press would solidify it enough to handle, and then it could be presintered in an ordinary ceramic kiln on a low setting, or maybe even a self cleaning household oven in cleaning mode.

The main thing is to position a mass of reasonably dense metal in the proper configuration & juxtaposition to the charge that it is accelerated in a focused "beam," and it probably doesn't matter how it's consolidated. I'm going to have to whip up a batch and try it with some different metal foils and powder (and it doesn't hurt that I've got a good friend who's CEO of a company that specializes in metal powders). Copper powder is cheap (or free, if you know how to ask for it), and I've got some tungsten powder around as well. And there's a company that sells whole kits for making frangible bullets out of the stuff. I'll post their name as soon as I can remember it.

Just remembered the name of that company with the powder swaging gear & materials. It's Corbin. They've got some cool shit. Check 'em out.

Oh, and one more thing, troops: I occasionally will wander over to Firefox's website to see how they're doing, and I just about shit my pants when I saw some new additions to the product line. They've got Dibutyl Adipate, Dioctyl Adipate, Dioctyl Sebacate and lots of other wonderful shit for plasticizing various concoctions! Kinda, ironic, huh? CPSC has a microscope up their ass 'cause of Oxidizers & hot fuels, and now they've got the best shit in the world for making plastic boomstuff. I have a friend in Idaho that I'm going to send in to buy it OTC for me, so there's no trail. Hallefuckinlujah!!!

So, whaddaya' think?

I have some results.

It seems that MF is not a bad primary at all. I will post all of the results relating to that in the MF thread.

I used 1 gram of PETN pressed into my aluminum casing in three increments. The casing dimensions are 1.785" long, .368" OD and .250" ID. Next I pressed in .50 grams of MF. The loading pressure is unknown at this time until I receive my pressure gauge. My best guess is that I had about 1000-1200 lbs on the 1/4" column.

I had a first fire composition of .15 grams of 4FA black powder. It was then simply fused, paper wading was added then epoxied.

My witness plate assembly served two functions. First just as a witness plate and second to test the capabilities of my blast shield. The shield is 1/2" lexan polycarbonate. The poly is exactly 2.5" away from the witness plate, exactly the same distance as from the blast shield in my press.

The ends are long and sharpened to be hammered into the dirt to keep the assembly in place during the test.

The polycarbonate took a hell of a beating. It is scared all up, and it completely cracked with shrapnel embedded in it, although nothing penetrated. I am unsure what to draw from this test as a measure of my safety because I think the threaded rods held the poly in place when it would have in fact became shrapnel.

The witness plate is 1/8" steel. I do not know the alloy, but I believe it was cold rolled. The steel is warped and dented quite a bit. The washers are disfigured and looks maybe melted? The aluminum casing looks like it was welded into the steel. If I recall correctly that is the only way some materials that cannot be welded are joined- with explosives. Very cool...

I placed a board 18" away from the test to block any shrapnel heading my way. I was also 100 yards away, but its best to be safe.

I would like the input of others opinions and thoughts. Is the PETN living up to its full potential? Any ideas for improvements?

Anyways I have lots of pics here.

More of the pictures, I could only upload 5 for each post.

Edit: I was reading somewhere that MF reacts with aluminum, I forgot where and cannot find it again. Does anyone know if this is true? COPAE says that nobel used copper and aluminum caps. Nowhere else do I read that it reacts with the aluminum metal, but I would like to verify that.

The polycarbonate took a hell of a beating. It is scared all up, and it completely cracked with shrapnel embedded in it, although nothing penetrated. I am unsure what to draw from this test as a measure of my safety because I think the threaded rods held the poly in place when it would have in fact became shrapnel.I think it's possible that the lexan sheet was being held so rigidly by the fasteners that it cracked instead of flexed.

It should be tested in the configuration that it's being used, if possible. If it's no good, you need to know NOW, not after an accident.

The cap seemed to be directional, almost as if it were a SC, laid on its side. But a lot of heat was generated, quickly!

Very nice al93535!

Indeed it would appear that MF has some use, and success at over 20,000psi would indicate that possibility of dead pressing isn't an issue.

Nice set up with the witness plate and polycarbonate shield. A second layer of polycarbonate over the first with a half inch air gap would however alleviate any fears of shrapnel making it through.

If your numbers are correct then I cannot see you could extract more performance from your PETN but I can't help but think the Al tube should have split under that immense pressure. If you could repeat the experiment I would include an ACCURATE density and pressure measurement of your pressed PETN and just shoot for 10,000 psi, you may find that at this slightly lower density the critical diameter decreases and you could get a more brisant detonation?

Either way your choice of steel was a great call so you know what to use next time!

My experiment with 600mg ETN on 3mm Al at 3500 psi gave similar results albeit on a smaller scale. Your PETN was far more brisant to have caused plastic deformation on those metal washers, it could however be due to a concentration of microscopic Al shrapnel. Heat has NOTHING to do with it.

either way a fantastic effort.

EDIT:

I have just noticed the shrapnel strike on that washer in the sixth image you uploaded,,, WOW that's really something! If those washers are made from steel then your PETN must has accelerated that fragment of aluminum to quite some velocity... I found a formula for that once but it escaped me!

Your PETN was far more brisant to have caused plastic deformation on those metal washers, it could however be due to a concentration of microscopic Al shrapnel. Heat has NOTHING to do with it.Washers have NOTHING to do w/it- but what do you suppose caused the discoloration on the back side of the 1/8" plate?:rolleyes:

Washers have NOTHING to do w/it- but what do you suppose caused the discoloration on the back side of the 1/8" plate?:rolleyes:

Light hitting the plate at a different angle or erm... DIRT :rolleyes:

I just refuse to believe that a <1 microsecond or so duration even of 5000 celcius is gonna melt anything visible to the naked eye.

The only thing that I think melted was the aluminum casing for the blasting cap.

For instance, in flex linear charges we used for door breaches. They were shaped charges of C4 with a copper strip in front of them. When detonated, the copper strip became liquid and cut through the door. Many of you understand the concept of shaped charges so you already know this. I understand that in shaped charges the explosive energy is channeled directly into the metal where as a blasting cap obviously doesn't do this. But I still wouldn't doubt that the casing became liquid for a short period, especially aluminum.

Awesome work al93535. When you get a pressure gauge, it will be much nicer to know your densities and pressures with accuracey. Looks like you're getting great performance out of your PETN though :cool:

- Copper liners in shaped charges categorically do not melt. It is one of the most often repeated mistakes in the field of explosives and it is proliferated even by otherwise knowledgeable people, but high-speed measurements have shown that the temperature of the liner does not exceed about 450 C.

- The detonation of any HE charge propagates in a predictable manner from the point of initiation, and the shockwave gets more powerful as it travels through more HE (up to a point). I like to think of it as a superposition of the shockwaves from initiated (by the shockwave) differential volumes of HE. Regardless, it indeed gives a directional effect which is utilized in many types of charge geometry.

Oh I see. Thanks for the correction. In demo classes we were always taught that it did melt. Unfortunately the military does teach some things that have since been proven false and continues to teach them anyway. Perhaps it enters a "semi" liquid state?

Perhaps it enters a "semi" liquid state?

If by "semi-liquid" you mean that it seems to move fluidly, than you could say that. But the fact of the matter is the solid metal is simply plastically deforming under the phenomenal pressures of detonation.

Personally, my confusion arises from the fact that a denser liner does not create better penetration. It seems like lead, tungsten, etc. would be much more effective at forming jets than copper or glass, but this is not the case. :confused:

Well to be fair the melting point of a substance does become lower under pressure so couldn't you conclude that under a pressure of 250kbar say, the melting point of copper for those microseconds could be in the vicinity of <450C?

In general a denser liner is better but lead (11g/cm^3) as you say does not give great performance. I am not familiar with the use of tungsten (19g/cm^3) but tantalum at nearly 16g/cm^3 has performance which is second to none.

It is however extremely expensive, some three times the price of tungsten.

In addition to the high speed temperature measurements, experiments have been conducted (and I regret to say that I can't give you the exact reference, but I think it was a document that was posted either here or on sciencemadness) where the liner was parted into a number of pieces and then reassembled prior to firing. Then the SC was fired into water, after which the collapsed liner was recovered. It was found that the pre-detonation partings were still present, although the geometry of the liner had obviously altered considerably.

Back in the day, I had a friend who worked at Westinghouse Marine Systems. He designed the launch tube system for the MX/Peacekeeper missile, which he based on the launch system for the Trident SLBM, having managed many upgrades for that.

He had an extensive library of test footage at his house, from China Lake to Aberdeen to White Sands to who knows what "undisclosed secret location." One of the tapes he showed me demonstrated superplastic deformation.

By far, the most dramatic depiction was one of an early model Mk.82 500 pound general purpose bomb. It was a cast Iron casing loaded with composition B, Which is 60% TNT, 40% RDX and a little Beeswax for a binder. I don't know how many frames per second the thing was shot at, but the film magazine must have been huge, since the event was sliced up pretty thin.

Upon detonation, the center of the fuze started to protrude almost imperceptably. Then, the casing shuddered slightly, and suddenly the paint began flaking off and the whole thing started to expand. Cast Iron is brittle, but the case was swelling up like a balloon, stretching to over twice its diameter. Light began showing through small fissures in the case wall as it continued to expand for a bit, and then the chunks that were still intact began to shrink noticably faster in relation to the cracks, indicated by the rate that the fissures were growing, than they would be from the outward travel alone.

I love slow-mo anyway, and we replayed that sequence 'till you could damn near see through the tape. My friend then went on to explain how the phenomenon works, and how it's used to form metal parts, especially with exotic metals and alloys that were difficult or impossible to form by other means.



One of the things he stressed was that the temperatures of immediately retrieved fragments were much warmer than could be calculated using the caloric content of the fuel (explosive), metal mass and starting temperature, co-proximity, event duration etc. So, how to account for this discrepancy?

Ever bend a coathanger or piece fo baling wire back & forth real fast? Burnt the piss out of your fingers, didn't it? There are two primary mechanisms in that deformation that cause this. One has to do with internal friction, where intergranular displacement causes the grains to dislocate & then rub against each other, sort of an opposite of thermal ratcheting. The other involves inTRAgranular friction, where shear planes develop within individual grains which cause individual atoms, or molecules (in the case of intermetallics), to work against one another, and when these regions develop enogh opposing force it can break the the intermolecular bonds, releasing even more energy in the form of heat, which creates more pressure, which creates more heat, and back and forth until the external force is removed or a failure insues. (By the way, all metal failures happen, microscopically, in shear, regardless of the direction of the external strain, such as tension, torsion, compression etc.) As one of the most brilliant metallurgists I ever worked with stated, "Pressure IS heat, and heat IS pressure.

So, what you've got with your metal in close proximity to a high energy density detonation is a little heat from the actual caloric release of the explosion/combustion, and a lot of heat from the deformation caused by the sudden pressure. Now we've got another bug in the equation. The only way to get an absolutely omnidirectional expansion field is to have a perfectly shperical secondary charge, with a perfectly spherical primary charge in the center. And now we have to deal with proximity effects, which are dependant on the square root of the distance from the energy emission. Hence, when you double the distance from the source, you only get one quarter of the energy impact, be it light, heat,sound, or whatever. This is known as the Inverse Square Law. And a variation comes into play when the shape of the charge is different, as in the case of the cylindrical device in question, which not only emits energy in an uneven manner, but the effect is amplified by the fact that it "burns" much like a cigarette, albeit very quickly, from one end to the other. This, in turn, has an effect on both localized strain rates, and the direction of the internal shear planes, which will actually warp, multiply and intersect, making an exact calculation of heat generation nearly impossible. And of course the heat softens the metal, the result being superplastic flow.

I'm fairly sure I've failed to present these phenomena in any coherent manner, but if you juggle 'em around a bit, it might make some sense. I think i'll probably need to tie a few loose ends together soon, out of common decency if nothing else. God help me if I ever have to write a doctoral dissertation!

So, whaddaya' think?

I would assume the stain on his plate was from the black powder used.

All other damage is from shrapnel/pressure.

al93535 - Next time to you do something like this, could you include something that gives us an idea as to the original orientation of the charge? Even if you just write "fuse" under where the fuse will be sitting, so we have an idea about direction.

Hence, I would ask you to clarify the second to last picture in your last post (attachment (http://www.roguesci.org/theforum/attachment.php?attachmentid=989&d=1226802359)) and ask if that picture is taken from where the fuse was sitting and if that "spray" pattern is from the bottom of the charge.

I gave a picture which showed exactly how I placed it when it was fired. I drew alignment marks as well to ensure its exact position.

http://www.roguesci.org/theforum/attachment.php?attachmentid=981&d=1226802298

I wrote "TOP" to try to orientate everything, however it was erased during detonation from the top side of the steel. You can however just slightly make it out. In that picture the detonator is laying directly away from you, fuse end toward you, loaded end away. If that makes sense.

Yep, that is what I thought. Just clarifying. Perhaps mark the side of the plate or just photoshop a mark in later.

That way, if you come back to your pictures in a couple of months and look at it, you yourself will know where everything was.

Good job.

Yafmot, may I add something to your description of metal heating? The friction is not the only cause of heat (and yes the heat of the detonation products does little), but even a flat steel plate backed up by HE will heat up, even if it does not bend or deform at all. This is called shock heating, caused by the nonelastic shock going through the material (possibly causing spalling at the other side, but that's another story). There's a good explanation of this in Cooper: Explosives Engineering. Basically you take a round trip on the P/V plane, and the area you circled is the heat generated.

And to this I would add that there have been many cases of tankers injured by spall who barely bled a drop, because the fragments were hot enough to cauterize the wounds.

PETN detonation video:

http://www.apcforum.net/forums/index.php?act=attach&type=post&id=474

You can read my post and info:

http://www.apcforum.net/forums/index.php?showtopic=3070