I decided to start my own thread for this, as the HE section seems kind of dead, and I don't want people to miss this as I think it is useful information. Hope you don't mind Mega.

I've noticed the lack of informtion on ETN on the internet, and no one is really sure how it measures up to other explosives other than it is "similar to PETN and OB positive". This is why I have gone through the trouble of making these calculations. Through the calculations, I will be posting the measurement of PETN for the given equation so we can compare the two. Incredibly, ETN exceeds PETN in a couple ways, although loses out in the end due to mols of gas produced and VoD. All PETN measurements were taking from "The Chemistry of Explosives" by J. Akhavan. If you don't feel like reading through all of it, the final calculations are listed at the bottom.

Purpose: To better understand the technical aspects of the explosive ETN and to be able to apply the knowledge/equations used to other explosives.

Information that follows contains: Heat of Formation, Heat of detonation, Heat of explosion, Gas output, Power index in relation to H Form and Gas output, and Temperature of explosion. I also will add a little formula for calculating approximate VoD at a given density.


Heat of explosion and detonation:

Heats of Formation:
ΔHf(ETN) = -483.2 KJ mol = ΔH1 (PETN = -538)
ΔHf g(CO2) = -393.7 KJ mol
ΔHf g(H2O) = -242 KJ mol

CO will not be mentioned since ETN is OB positive. Oxygen and Nitrogen gas are not counted. Heat of formation is the amount of heat energy released when a given chemical compound "forms" when they establish new bonds.

ΔH2 = ΣΔHf g = (4) -393.7 + (3)-242 = -2300.8 KJ mol

The numbers multipled by the Hf of the gases where determined by the number of mols of each gas released from detonation. These can be seen in the decomposition of ETN:
C4H6N4O12 --> 4CO2 + 3H2O + 22 + 1/2O2

ΔHd (detonation) = ΔH2 - ΔH1 = -2300.8 - -483.2 = -1817.6 KJ mol

Converted to KJ Kg = Q = -1817.6 (1000)/302 = -6018.54 KJ Kg
The 302 is grams per mol for ETN, which actually exceeds PETN in energy per gram, albeit slightly.

ΔHd is the heat of detonation. It is the amount of heat energy released by 1 mol of explosive. A negative number means an exothermic reaction, which is not suprising since we are dealing with explosives. ΔHd for PETN = -1831 KJ mol and Q for PETN = -5794 KJ Kg

Gas Output:
As we saw before from the decomposition of ETN, 9.5 mols of gas are liberated per mol of ETN. According to the Ideal Gas law, 1 mol of any type of gas will occupy the same amount of space, regardless of atomic weight. For instance, at STP (standard temp. and pressure), 1 mol of a given gas will occupy 22.4L of space. This factor is part of what gives an explosive its heaving force. Also involved is the amount of heat produced, which will effect how "hard" these gasses heave. To find the volume of gas produced, we take the number of mols in gas: 91/2 and multiply it by the amount of space each mol will occupy : 22.4L
91/2 (22.4) = 212.8L = volume of gas per mol of ETN
To convert this to mols of gas per gram, take 212.8/302 = .7046 L g
mols of gas per gram for PETN = .780 L g

Temperature of explosion:
This is were things get interesting, and some guess work must be done. Temp of explosion is exactly what it sounds like. Te is the maximum temp which the products can reach under adiabatic conditions. In the following equations, whether a number is negative or not is paid not attention as there is no addition or subtraction of negative numbers and we know that temp of explosion will be positive. For this problem we use equation:
Te = Q/ΣCv + Ti
Q = Heat of detonation that we figured out earlier, ΣCv = Summation of specific heat capacities of the products, Ti = Initial temperature, which we will say is 0*C = 273K

The equation is then rearranged to Q = ΣCv (Te - Ti)
This is done because heat capacities of the products change with temperature, making this equation difficult to work straight forward. So this is where we play the guessing game, more or less. We look at RDX frpm a different source and see that its Temp of explosion is 4186K. We can assume ETN will have a higher Te since our previously calculations on heat energy have been more than RDX. So we will guess 4500K and plug it into the equation. Note: This wasn't my first actual guess, it took me a few times...

First I will list the specific heat capacities of the products at 4500K:
CO2 = 50.43 J mol, H2 = 42.3 J mol, N2 = 27.154 J mol, 1/2 O2 = 21.056 J mol
To find ΣCv, Multiply the given specific heats by the number of mols of gases from detonation. This will give you 403.984

Now subtract the Ti which we decided would be 273K from our guessed Te, 4500K.
4500 - 273 = 4227

Now we have the eqaution all set up:
Q4500K = 403.984(4227) = 1707640
This is in J mol, to convert it, multiply it by 1000 and get 1707.64 KJ mol. This is how we check ourselves. Earlier, we calculated that the heat of detonation for ETN was -1817.6 KJ mol, not 1707.64. This is how we know our guess is too low. So now we guess again.

This time we will try 5000K. Specific heats for products at 5000K are:
CO2 = 50.949 J mol, H2 = 43.137 J mol, N2 = 27.397 J mol, 1/2 O2 = 21.248 J mol
ΣCv = 409.244
Te - Ti = 5000 - 273 = 4727
Q5000K = 409.244 (4727) = 1934520 J mol, or 1934.52 KJ mol

Now this guess is too high! This is where your graph drawing skillz come in to play. On your Y axis, you label Heat Liberated in KJ and on the X you have your Temp of explosion. Plot the calculations for 4500K and 5000K and draw a straight line through them. Then, plot on the Y axis the actual heat of detonation we calculated earlier, or 1817.6 KJ mol. Now draw a straight line from that point through the line you drew for the other two points. Where they intersect is your accurate Temp of explosion for ETN. Excel could prove helpful, but I'm not fluent in excel, so I had to draw it out.

I put it at approx. 4721.25K = Te. I havn't calculated the Temp of explosion for PETN yet, but RDX, as mentioned early is 4186K, exceeded greatly by ETN. Remember that these measurements are approximate, as not all enviornmental factors are being accounted for.

Power index and explosive power
Now lastly, in a comparison to other explosive, we can produce a power index and explosive power. Explosive power is the heat of explosion multiplied by gas output in mols per gram of explosive and then divided by 10.

Explosive power = 6018.54KJ Kg-1 (.7046) / 10 = 424.06

Explosive index is this value multiplied by the explosive power of a standard. In this case, we will use TNT as the standard, which has the explosive power at 314.3.

So we take 424.06/314.3 (100) = 134.9% for ETN compared to TNT. Some other explosives are listed below. This is where ETN loses out, as it doesn't have a very impressive gas output. There are other ways to compare explosives power that include VoD, but this is a simple way to do it.
PETN = 143.7%, RDX = 145%, NG = 145.8%

VoD Calculations:
One misconception I see commonly is the thought that an explosives VoD is constant regardless of diameter or density. This is Very false. I am not aware of the equations for the effects of diameter, but I can tell you that all homogenous explosives have a critical diameter and the smaller it gets, the lower the VoD. The following equations are based on density alone and assume perfect diameter.

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

:o Thats a big difference! Not exactly disappointing, but definitely makes a substantial drop in VoD. This can be applied to ETN, which is rumored to have a VoD of approx. 8000 m/sec. The following equation can be used to find approx. VoD, but I can't seem to figure it out. Let me know if you can!

Vpx = 430 (nTd)1/2 + 3500(px - 1)
Here, V is the VoD of a given density p, n is number of mols per gram of gas produced and T is temp in kelvin at which the detonation occurs. Good luck!


Last notes
One more point I'd like to make: For those of you having troubles with ETN yields, my advice is temp control is everything! Last night I had a dream of mixing 50g ammonium nitrate with 100mL sulfuric acid, never exceeding 20* C. The reason for this can be seen in [list]
this article here (http://www.roguesci.org/theforum/attachment.php?attachmentid=992&d=1190786433"), which is posted at RS. It may not be available as RS is going through some reconstruction, but it will be in the future I'm sure. In short, past a certain temperature, sulfuric acid stops reacting with ammonium nitrate to produce nitric acid and NOx fumes and other unwanted products are produced instead. The temp listed is 30* if I remember correctly. So anyway, I allowed the mix to cool to 10*C and then slowly added my 16g of erythritol at about 1-2g per minute. The temp never went above 12* and after adding all the erythritol, I let it nitrate for an additional 20 minutes.

The mixture at this point is thick like honey with ETN crystals and is dumped into distilled water, filtered, washed with bicarb, rinsed with distilled water, washed again in bicarb, and again rinsed. pH is tested with litmus and washing continues until it is at 7 pH. I havn't measured my dry product yet, but I'm guessing it will be around 24g if not more.

I recall in my first trial runs with ETN, I got shitty yields. I attribute this to being impatient with my nitration and letting the temperature get too hot during both the nitrate addition and the erythritol addition. Lack of nitric acid and excessive heat will MURDER your yield. I would get pissed because I would get such crappy yields. After a certain temperature, probably 20*C, the mix will no longer nitrate the erythritol, but will dehydrate and destroy it instead. I see many other people making this same mistake. So point being: Be patient, use proper cooling equpment (eg ice/salt bath), stay in the correct temperature range, and be safe. Oh yeah, I also took a picture in my dream of the yield, which I will post later.

So I hope this information is helpful in comparing ETN with other explosives. If you have any criticism, ideas, comments, please feel free. To sum it all up:

ETN info:
Heat of detonation: -1817.6 KJ mol
Heat of explosion: -6018.54 KJ Kg
Volume of gas produced: .7046 mol g
Temperature of explosion (approx): 4721.25K
Power index in comparison to TNT: 134.7%

The "birthday" of ETN from a professional perspective is November 20, 1928. If one is ever hunting for patent literature as well as applications within industry that date will get quite a few returns. In fact that date comes up for search returns on differing years ('32 for example)...I don't know why.

Random thoughts:
While reading, I saw frequent compositions of polyol esters and (cyclic) nitramines. I have often seen PETN/RDX in NATO munitions. But RDX is somewhat costly in terms of yield vs. acid utilized.
ETN is easily produced while PETN requires a precursor that is somewhat difficult to find (but not too difficult to synthesize). RDX uses a simple precursor but is "expensive of acid". However there exists energetic nitramines that are simple & cheap to synthesize: R-Salt, NitroGunanadine, NitroUrea.
NitroGunanadine & NitroUrea are made in a similar fashion in that they are introduced to a dilute nitric acid to make a "product-nitrate" and at a 2nd stage are introduced to sulfuric acid to produce the "nitro-product". R-Salt is even simpler. If PETN/RDX are somehow "energetic sisters" that are coupled together to make a superior munition, why not use ETN and a similar nitramine? Certainly this would stretch the bulk level to make a very fine plastique! Just as C4 uses RDX/PETN: why not use ETN/"simple nitramine"?

Just as C4 uses RDX/PETN

I think there is an error here: real C4 is not a blend of RDX and PETN but is just a plasticized composition of one explosive- RDX.

QUOTE]If PETN/RDX are somehow "energetic sisters" that are coupled together to make a superior munition[/QUOTE]

RDX is not chemically related to PETN as RDX is classified as a nitramine and PETN is a nitric ester.

Another fact is in military munition PETN and RDX blends is not well known or widely used; its more common to find blends of PETN and TNT in now decommissioned pentolite and RDX and TNT in composition B and Cyclotol (which is gradually being phased out )and replaced with insensitive high explosives such as the recent blend of NTO and TNT and other plastic bonded explosives which are more stable to cook off during adverse storage conditions and operating environment.
In the early days PETN is used for munitions but was replaced by RDX due to the better stability of the latter.
But
You are right that the RDX is costly as by direct nitration you get more yield with PETN than with RDX.

That is interesting that you mention R-Salt. It is indeed OB negative and the addition of ETN could benefit its performance. I believe R-Salt has a VoD of around 7800 m/sec, which is excellent.

Another good thing about R-salt is the ability to synthesize it without using concetrated acids, which can be expensive. It also avoids the use of nitrates, which are closely watched by big brother. Not to mention I try to avoid using too much AN in nitrations, as I like using it for the base in my larger charges.

The down sides are that it is carcinogenic and the yields are less than satisfactory. Perhaps a method can be made to improve these yields? I remember reading on Mr. Cool's site that he yielded just 3.3g of R-salt from 7g of hexamine. Some are more willing to accept these risks however.

Combining the ease and cheapness of R-salt production and the positive OB and good yields of ETN could be a good mixture. I would just be cautious if I did decide to synthesize some (R-salt), as it does cause cancer if absorbed through the skin or inhaled!

A good mixture would be 80/20 ETN to R-Salt to convert hydrogen to water and carbon to CO.

Realistically almost everything is carcinogenic to some degree....no? It depends on the level of exposure certainly. I have done some experimenting with R-Salt and it may really be worth your time if you enjoyed ETN....

And, yes the yields can come up to about a solid 50% of the level of hexamine (which I think is a numeric 60+%). When thinking of nitrating hexamine directly into RDX the yields are close to that unless you start with the dinitrate.
If you start with the dinitrate and really keep the ph level to the right and keep the whole thing seriously cold - you will get a better yield...especially if you re-cycle the "bathwater". It's not that bad, really. What you end up with is worth the effort. The 1st time you try it it may goof on you as timing, temp and order of progression in the lab (including the size of the beakers....it foams like a bitch) but you get to be good at it and it's fast and simple. PM me - I have personal notes.

Well I think I could live with 50%. They are actually having a sale online for 4x500g lots of hexamine for 25$. Not bad if you ask me, thats 1kg of R-salt. The only real expense would be the hexamine, as nitrites and HCl are cheap.

Charles: Have you done any experiments blending R-salt with ETN? Or ETN with any other explosive for that matter. I personally have only mixed ETN with NM and NG, both having excellent results. I actually preferred NG, as it isn't nearly as volatile as NM. Here is a video (http://s164.photobucket.com/albums/u6/pudgedog69/?action=view&current=ETNNG2.flv) of a ETN/NG charge I made. It was about 5g if I remember correctly, and formed a pellet smaller than a quarter. I calculated approximate density to be about 1.4g/cm3. Mix was 80/20 ETN/NG.

Hickey: I remember using C-4 all of the time, and if I think it was 91% RDX and 9% plasticizer and binder. PETN was only used in conjunction with C-4 in detcord as a means to effectively detonate the C-4 main charge and C-2 (a comp. similar to C-4) in detaprime boosters. But yeah, PETN and RDX were never mixed. I only left the military recently, so I can't be certain about past compositions used in the armed forces. Perhaps PETN/RDX was used at one point? I'll check it out on google.

EDIT: Of course I forgot SEMTEX!
Semtex: 45% RDX, 41% Petn, 11% HC oil (paraffin), 1.8% Butadien
I also found some mines that are PETN/RDX : (AP Blast, 140g PETN/RDX - Pentolite - Zimbabwe)
(AP Fragmentation, 500g PETN/RDX - Pentolite - Zimbabwe) (Information courtesy of http://www.nolandmines.com/explosivesinmines.htm)
I understand that none of these compositions are in use by the United States today, but SEMTEX is a well know mixture made in the Czech Republic. If ETN and PETN are so similar, could ETN not be substituted in the mixture to make ETN/RDX compositions?

Obviously I was not going to deal with minutia about my musings, yes Semtex is what I meant, the utilization of nitramines and esters is common in Warsaw Pact countries and some NATO munitions especially munition that have size variants like a SAM of shoulder launched size, bla, bla... (These are topic directed issues not some frigging Democrat debate where you look for little mistakes to jump on for points from an audience.)

Rbick:
However getting back to R-Salt and even the nitrourea/nitroguanadine mixes with ETN/PETN - they really do have a value. My first close look came from getting an energetic bulking agent for a plastique and that's how I stumbled upon those three.

What was compared was real sweet, well re-crystallized RDX and R-Salt; side by side. What was used was a simple detonator tube closed at one end with a quality primary (silver azide/tetrazene) as an initiator. The test samples were the base charge at a one gram level compressed with the equivalent of 1400lbs. Witness plate was a square of Al plate 4mm in thickness. There was really no difference. The old USBoM "bent nail tests" - no difference. I know that RDX will shoot higher but at the level of practicality.....it's real damn close. The RDX was damn fine-quality material by the way.... Some of this may be in the notes I sent: I don't remember.

Upshot of the whole deal......I think it's really worth a look. it's cheap. fast. & allows for experimentation and there is some material on it. It's mostly German but a friend got down to translating that and some tetrazene material for me as I became very "guanadine wealthy" recently. However, in the contextual comparison of enjoying ETN, these things are really fun and "do-able".

EDIT:

Here is some search material that may or may not be in the notes: CTMTNA, Cyclotrimethylentrinitrosamine, most recent work was by a guy named Hass, the man who did the US research (I -think- his name is Baun, is the guy who worked with RDX for Los Alamos), check a search for nitramine salts, the German term is "R-Salz"; this was a WWII phenomenon in response to lack of high grade HNO3 in the latter stages of the war.
Enclosed is a French patent that has a Hell of a lot of info. If you don't speak French just read it slowly and check it's refs. It describes the industrial mechanisms for making R-Salz on a production level and it's economic viability. It's actually really useful, but you have to read carefully and study it at length.

Since we got to the blends, have you looked into aluminizing ETN, some of its decent VoD could well be traded-off for some extra power (the optimum point of course being where the two curves, one increasing energy with metal-% and the other decreasing in VoD, cross)? One only has to remind though to not simply calculate the VoD merely from the drop in the explosive's density, as aluminium for instance acts quite endothermically in the detonation front and thus lowers the VoD, actually even more so than most inert heat absorbing materials like sand or salt. With higher density the error maybe quite marginal for our needs though, at least with TNT it seems (Melvin A. et all gives values of 6800m/s @ p(1.75) for 80/20 Tritonal, while 6900m/s for 80/20 TNT/Sand of the same density).

And thanks for that info, COP. I wonder if we have any French around for translation though, it seems highly informative indeed.

Just a little update: I successfully made and detonated 40cm of ETN detcord. What I did was bought some flexible rubber tubing, although I forget the diameter of it. It was about the same as commercial detcord. I used a long flexible wooden dowel (1.5m) to press the ETN into the tube. I was able to press it quite well with this method. Total weight of ETN was about 8g. I'll edit and update the diameter information later when I get a chance to take a look.

I wrapped it once around a fairly thick tree. It didn't cut it fully, as I should have picked a thinner tree, but the damage was decent. My camera died on my way to the site, so I didn't get any footage :mad:

Initiation was 1g ETN w/ .5g AP cap by 12v lantern battery with electric match. Next time I'm going to try 12% Al 88% ETN and see what happens. I think 12% is balanced for H2 and CO gas if my calculations are correct.

as aluminium for instance acts quite endothermically in the detonation front and thus lowers the VoD

Do you mean exothermically? The heat of formation of aluminum oxide (which is created when the mixture detonates) is −1675.7 kJ mol, which is a lot of heat energy. I know Al decreases VoD, but raises the heat output (heat energy) of the explosive substantially.

BTW Thanks for the notes Charles, they are very helpful. R-Salt is the next on my to do list. I'm just going to be cautious about handling it when I do make it. Damn those carcinogenic properties!

Do you mean exothermically? The heat of formation of aluminum oxide (which is created when the mixture detonates) is −1675.7 kJ mol, which is a lot of heat energy. I know Al decreases VoD, but raises the heat output (heat energy) of the explosive substantially. Yeah, but some Al2O(g) is also formed, which effectively competes with the other, more exothermic detonation products by using their oxygen and thus in the end giving an endothermic overall effect. The Al2O/Al2O3 ratio is however reduced with density (-> higher pressure, favors more Al2O3(s) over gaseous Al2O), some Al2O will still always remain interfering resulting in at least a slight drop in VoD. So if it generally is important for one to pay each and every effort to attain maximum possible density, it definately is so with most aluminized explosives. :]

Ok I see what you're saying. Learn something new every day :) Adding aluminum is an interesting issue. I think the point you want to avoid is where the aluminum starts stripping Oxygen from CO, creating a solid carbon byproduct, which decreases gas output. This would have a huge negative effect on VoD, obviously.

I think ETN could afford some loss in VoD, considering its already impressive VoD. So adding Al is definitely something worth trying.

The Al2O probably reacts predominantly with CO2.

The point you want to avoid is when the Al content and temperature is so high that Al2O3 starts to decompose to Al2O (actually first to AlO, which mostly converts to Al2O in the presence of sufficient reducers) at an increasing rate (according to Melin A. et al. that's somewhere at 3500K in high density aluminized explosives) and decrease the detonation velocity and pressure. There will actually be a buffer zone in terms of temperature; too hot->Al2O, too cold (<2500K) and Al2O3 starts kicking in and the temp rises back to the equilibrium point. And if anyone was wondering by now: only a couple percentages of aluminium usually burn in the shock front, the rest react far behind. I'm not sure if that made any sense (I'll put it down to the booze), good luck anyway.

Aluminum oxide produces high energy but must produce it at relatively low temperature.

This is because by far most of the energy produced arises from the liquification / solidification / crystallization of the gaseous species. The gases have low heat of formation, the crystals have high heat of formation. (I forget values for the liquid phase.)

Worse, Al2O3 has a low temperature of decomposition (~2,000*F??), and since it does not exist above this temperature it cannot contribute much energy until the environment's temperature falls below its decomposition point.

In the space shuttle's boosters, the temp and pressure (~1,000 psi) are such that CO2 oxidizes aluminum and CO does not interact with aluminum.

There is a certain maximum concentration of aluminum (below stoichiometric) that absorbs enough energy from the reaction of the other elements that detonation does not occur above this concentration, which is on the order of 20%.

However, if you wish to make a better flash powder, a mixture of 42% aluminum / 58% ETN is stoichiometric.

Also, granulation size affects the maximum percentage of aluminum compatible with detonation.

All this is not too relevant, but needs to be said somewhere, sometime.

I understand this has been discussed before, but I have recently tried casting ETN for a booster charge. Although I haven't tested it yet, the results have been good thus far. The thing that makes ETN easy and safe to cast is the contrast of its melting point and its decomp. point. It melts at 60*C and decomposes at 160*C. 100 degrees is a comfortable range methinks. This is the problem with RDX and HMX, both of which have melting and decomp. points that are too close for comfort. RDX has a melting point of 205*C and decomposes at 234*C :eek:

For the casing, I used a 16x75mm clear plastic test tube. 6 grams of ETN was pressed very lightly into the tube. Using my DIY hotplate (A skillet with the cooking plate removed), I heated water in a pot and held it at 75*C. This particular "hot plate" is capable of being set to low temperatures such as this. Using tongs, I held the tube in the water, making sure not to touch the bottom of the pot and checking it every minute or so. When the ETN had melted completely, I removed the tube and allowed it to cool. It is incredible how little space 6g of cast ETN took up, less than half the tube. I will measure the density later, but I can only imagine for now that it is close if not at max density. There was no loss of the explosive due to thermal decomposition when introduced to the hot surroundings, at least not enough to be noticed.

When I'm ready to use the charge, I plan on pressing some primary on top of the cast ETN and detonating via electric fuse. I will video tape and post the results.

I think this method is safe if done correctly and very effective. It allows for maximum use of ETN without having to worry about pressing, which can be a problem if you don't have access to a nice hydrolic press. I'm going to make a guess that one of these test tubes could hold about 15g of cast ETN, which would make an extremely effective booster. It would be about the size of the detaprime boosters we used in the military, which were made of C2.

My reason for this is for creating an effective means of initiation for larger charges of PLX and AN/xx type compositions. For PLX, the test tube is closed and there would be no chance of liquid seeping into the charge prior to use, which I have had problems with in the past. Anyway, I'll let you guys know how it goes.

If I were you I would press a gram of ETN crystals onto that cast ETN before you add the primary. From what I gather the amorphous nature of cast ETN with few crystaline internal surfaces renders if insensitive and suseptable to LVD in the same way that frozen NG would be (physically and chemically they are VERY similar)

The critical diameter would be very large and I fear that this charge being so small and with weak initiation could fail to detonate or at least prove disappointing.

I have cast ETN before using hot water and although much denser than hand pressed powder, around 1.3g/cc, I believe that pressed ETN of same density has much higher performance than the cast... at least in the small diameters that we experimenters are use to dealing with. Of course if we were talking about you melting 600 grams and pouring it into a baked bean tin and using a pressed 10g ETN cap there would be no such worries!

Perhaps you could try to prove me wrong with an equivalent pressed charge at the same density (or as close as you can get). I've had 0.6g ETN at 3000psi puncture 3mm Al if that helps you to select a target. I would guess that this tiny charge probably had a similar density to your cast affair...

Good luck and look forward to the vid!

I also found some mines that are PETN/RDX : (AP Blast, 140g PETN/RDX - Pentolite - Zimbabwe)
(AP Fragmentation, 500g PETN/RDX - Pentolite - Zimbabwe) (Information courtesy of http://www.nolandmines.com/explosivesinmines.htm)


Rbick
I just happen to read your post and found something erroneous no matter how legitimate is the source of your information.
The author of that article did mentioned (as you restated) that some mines in Zimbabwe are filled with RDX/TNT – PENTOLITE which does not make sense. Maybe it’s a typographical error.
If you know that pentolite is binary composition of TNT and PETN; Pen is the prefix for penthrite (or PETN) and Tolite is another name for TNT you will not accept the erroneous nomenclature for the Zimbabwe explosive filling for their mines.?

Of course if we were talking about you melting 600 grams and pouring it into a baked bean tin and using a pressed 10g ETN cap there would be no such worries!

Don't be giving me crazy ideas Frank! :D Thanks for the pointers, I completely neglected the critical diameter in this idea. It seems I got a little too excited and forgot. I have in fact achieved 1.2g/cc with pressed ETN, which is decent but not nearly as much as I would like. I did detonate the 6g cast ETN in the test tube. I used 1g HMTD to initiate and from what I can tell, it seems to have worked. Here is the video. (http://www.youtube.com/watch?v=v7zw9ugs-vU)

The question is performance now. I conducted this det simply to see if it would in fact fully detonate. From the blast and upon inspecting the site and finding nothing but a hole, I can only assume full detonation. The presence of snow did not help my project, but there is nothing I can do about that for now. Hopefully this weekend I can try a performance test with pressed and cast ETN on a metal plate. I'll keep you guys posted.

Charles: I made my first batch of R-salt today. Just to let you know, you pushed me over the edge in finally trying the sythesis. Out of 7g hexamine, I got maybe 3.5g r-salt.

The web sites I found the synthesis on neglected some very important matters. Firstly, no site explaining the procedure mentioned keeping the reaction cool while adding the NaNO2 to the HCl. If not kept cool, A LOT NOx is created, wasting your nitrite! Also, the fact that the hexamine solution should be added slowly was not mentioned, which should be done for obvious reasons. And people wonder why they get such a low yield! I'm trying a second batch keeping an eye on the temperature.

A '60 industrial chemistry book reports "ETN melts at 61,5°, not very soluble at cold temp. and detonates violently from shock. More sensitive than NG itself".
Is it a mistake?

Yea.... I was actually thinking about the idiosyncrasies of that also. Pour slow; keep it seriously cold ( - 0 C, etc) and pour into a steep/deep beaker if you can get one....(so that there is minimized slash and swirl). There were two guys on SM who get real crazy over R-Salt; due primarily after they detonated about 10 grams of that mischief. It shoots close to RDX but is not as impact sensitive as either RDX or (especially) ETN. ....Personally I like it for the synthesis.

I see it as a way to "brew up something fast without mixed acid mess"... (sounds like a commercial). But if you are pouring NOx fumes; yea, the stuff is being wasted. I can get that synth so mellow that it can be done in-doors w/ virtually [next to] no fumes (slow pour - deep beaker). When you finally shoot that stuff, you'll like it. However it actually shoots very close to ETN so don't pop them side by side & expect a broad differentiation....Somewhere there is a synthesis that describes making the hexamine is situ (in solution) and moving on from there with R-salt thus cutting cost very deeply.

I know this is an ETN thread, but attached I have another paper on R-salt, or as this paper calls it, TMTN (TrimethyleneTriNitrosamine). It has some good information on temperature and quantities that effect yield. It also lists the amount of DMTN (DiMethylene) formed in certain conditions. TMTN can even be synthesized through a reaction between Sulfuric acid and a nitrite, although this is more difficult as sulfuric attacks and dehydrates the hexamine if left in contact for too long or is too concentrated.

It seems the yields are close accross the board and a method for improving yield is yet to be found, or not well known. I completed a r-salt synthesis last night and yielded 10g with 20g of hexamine used. The procedure was enjoyable and easy, with very few NOx fumes when kept below 0* C while adding the Nitrite solution to the HCl. I would like to try mixing it with ETN as well as compare performance to ETN. If I'll have time for this is the question.

Ever since I've become familiar with R-salt I've been somewhat blinkered by the thought that it was little more than a curiosity and a possible easy route to RDX. Maybe it could have real uses in its own right.
If you mix a 2:5 ratio by weight of molten ETN and PETN you end up with a saturated solution of PETN in ETN surrounding suspended PETN particles. On cooling this gives an extremely powerful if insensitive high density material which although needing strong initiation and confinement in small diameters, should be quite immune to LVD due to internal crystal surfaces of differing densities and probably a small amount of trapped air.
I read somewhere that R-salt IS compatible with NG so if it was not too soluble I would assume it could make a useful melt cast composition with ETN.
Obviously oxygen balance would suffer over pure ETN but the gain in real performance that comes from complete initiation would more than make up for this.
Going off topic but while we are talking about R-salt, I must say that if I didn't have recrystalized ETN in ice cubes in the freezer and I needed some nitric ester to mix with my R-salt for a quick shaped charge, would I go to the relative hassle of making ETN, drying, neutralizing, drying, recrystalizing, DRYING etc?! would I fuck... it would be nitro all the way! Its just too damn easy and economical :D

Well, I've played with it (R-Salt) a bit and I like it. I've compared it side by side with RDX, in a melt with ETN and by itself as a base charge. It's worthy material. It seems to "cry out" for usage as it's not heavy granular material but compresses easily and can play well with others. One thing however I have NOT tried was the NG/R-Salt fellowship. I would likly use ethylene glycol as it's available and I like the lab of it better than glycerin but it's really not important.....That's an idea.
The thing about a melt is that it's so stable. The mass made from an NG/powder is subject to "weeping" after a time. One of the myriad strengths of ETN is the cast melt issue. It's so damn easy to do, if you have the ETN to begin with, of course.

-->The trick is to form up the hexamine (not buy it, but synthesize it from inexpensive materials!) and develop the R-Salt synth on that inexpensive hexamine lab......thus the yield issue becomes a moot point!!!

Rbick
I just happen to read your post and found something erroneous no matter how legitimate is the source of your information.
The author of that article did mentioned (as you restated) that some mines in Zimbabwe are filled with RDX/TNT – PENTOLITE which does not make sense. Maybe it’s a typographical error.
If you know that pentolite is binary composition of TNT and PETN; Pen is the prefix for penthrite

Yeah good point, I didn't really pay attention, just kind of cut and paste. I am well aware that pentolite is PETN and TNT. Regardless, SEMTEX is a very well known and commonly used composition of RDX/PETN.

Charles: I found this site (http://www.frogfot.com/synthesis/hexamine.html)discribing the synthesis of hexamine from formaldehyde and ammonia solutions. Seems easy and cheap enough. Any ideas on yield or any other methods?

I've had trouble getting Formalin for less than $17 a liter and that's sort of steep. I had a Hell of a lot and got used to having it available....(that's another issue). The site referenced the 50gr formalin/10% ammonia "standard" synth that many folks use (myself included). Someone, some years back mentioned a little trick that is quite useful.

Garden & hardware stores sell ammonium sulfate, together with lye in a gas generation system you have a great little ammonia machine. Bubble same through your existing 10% ammonia (increased by another 10% at minimum) and THEN add your Formalin and you get some seriously high yields.
The ratios of Fomalin to Ammonia should be strong on the ammonia side. I read some synthesis that seemed very wasteful. One such was in the book Home Workshop Explosives, wherein Mr Presler (Uncle Fester) describes using nearly a pound of Formaldehyde to yield a pound of hexamine.... No way, dude! A pound could be done with MUCH, much less.

EDIT:
I almost forgot, I'm watching a re-crystallization of R-Salt at this point. Just as re-crystallizations of ETN purify and alter crystal structure, I have an interest in this w/ R-Salt. The trick is not using a solvent/heat (ETN) technique but just a "re-forming in the mother liqueur w/ temp extremes" type ... I'll post what I see. I'm trying to get a camera but I never have time to drive into town.

I was just about to mention the synth in uncle festers' book.

I have personally never tried synthesizing any hexamine, as for me it would extremely expensive, due to the cost of Formaldehyde. I can buy 500g of hexamine for £14, or ($28). This isn't exactly cheap either, but works out alot cheaper than the other route.

Fester states to add 2000 grams (1850ml) of Formaldehyde 37% to 1100 grams (1200ml) ammonium hydroxide. From this he reckons you should recieve 560 grams of Hexamine.

It wouldn't suprise me at all if this was an unaccurate wasteful lab. As we know Fester doesn't really seem know what he's talking about a great deal.

He even states further on in the RDX part, that you should add 100gs of Hexamine to 770ml of fuming Nitric acid!! :eek:

Mega states 75gs Hexamine to 300ml Nitric. I'll let you do the math...

Maybe Fester has high grade Nitric acid coming out of his taps, but I sure know that myself and most others don't.

Charles:

Don't go to town, Marshall!

Go to your computer instead... http://tinyurl.com/3e3pbf I can recommend this camera on personal experience.

I got the Cannon A630 8 mega pixel for Xmas, replacing my 5 year obsolete 3 mega pixel Olympus C-3000. This camera has it all, and has threads for an adapter to 52mm telephoto lenses. You should have little difficulty finding the microscope adapter you wanted for your crystallography pictures with this one- http://www.truetex.com/micad.htm

The ongoing reduction in price vs. what you get with digital cameras is a happy thing!

Bert: a serious thank you! (I have Canon EOS Elan lenses)- I'm a camera guy but have been into film (as opposed to digital) for so long that I hesitated to get a body of quality especially since they continue to move faster than ever. Now 12 Mp is the norm...That used to be a high end. I could spend about 300 for the body to keep using them: if I use a internet purchase. The Google links (further on up the internet road have some at the Power Shot price. Talk about old digitals, mine is a 1.5!

Emil: Just an opinion here but that is much too heavy on Formaldehyde. Steve Preston is not a stupid man but I think, 1.) he is wasteful of resources as he works in the chemical field and has sources up the butt, 2.) he is comfortable with high levels of reactants (acids) as this is a sure-fire method of getting the lab to work well.

For many the fun is finding the ratio, the proportion and the accuracy in the synthesis. Many hobbyists are detail oriented; he might not be - and this is expressed (especially) in something like nitrations. But with the Formaldehyde issue, I can vouch that you don't need that ratio of materials.

I don't remember the guy's name accurately* but there was a fellow who actually found that RDX nitrates at an optimum of about 5:1 grams of nitric acid to grams of hexamine. This would translate to about 4.ml acid to 1gr hexamine. 770ml of acid (@ 1.51) would put us at 1162.7 gr of acid for 100gr hexamine with Preston's method.....a bit wasteful. no?

Actually I think it was Bock* who found that hexamine would nitrate at 90% HNO3 and that anhydrous was not even needed.

EDIT: I had some actual light-industrial material on hexamine production but I don't have access just now; if anyone REALLY wants that stuff just PM me.