I have searched the forum and I do not see a solution to my problem.

Everything I have read suggests that Al that is higher than 400 mesh can be used for flash and that the higher the mesh, the more reactive the final product.

I am trying to make flash for reports in rockets using 625 mesh aluminum and 300 mesh potassium perchlorate in a 70/30 (perchlorate/al) ratio by weight.

The resulting mixture will barely ignite. When it does it burns slow and just kinda pops and sputters and usually does not burn completely (only about a 1/3 of the pile will burn).

I would have thought this mixture would at least burn consistantly but it doesnt.

The aluminum appears to be about as fine as flour and will leave a very fine dust on whatever it touches. The perchlorate was bought from a pyro supply house and is suppose to be tiawanese high purity.

I tried mixing the aluminum with permanganate and it lights with a 'whoosh' and a bright flash when unconfined. This makes me think the aluminum is ok, however, I would like to use the more stable perchlorate.

I have tried drying the perchlorate under a lamp and using a mortal and pestal to break up any clumps. Does nothing.

Any ideas what my problem is? Is the aluminum just not fine enough? Could the pyro supply house somehow got something mixed up and sent something besides perchlorate? I am at a loss to what is wrong and any information would be greatly appreciated!

How fine is the perchlorate ? Will it oxidize anything else, say charcoal ?
It is possible that you were sent the wrong material. I've heard of this
happening but rarely. BTW, the mesh of your Al powder seems OK judging
by its reaction with permanganate.

I do not have a good source of charcoal. I could always grind up some briquettes, or use graphite, or buy some activated charcoal for use in filters, but I am not sure how this will react compared to pyro grade charcoal.

I did mix the perchlorate with some powdered sugar and it did ignite but it was slow burning when unconfined. It did completly burn though. I added some sulfur and it behaved about the same.

The perchlorate is suppose to be the best this supplier carries. The extent of my pryotechnic hobby is basically rocket motors. I have not used perchlorate before or made flash for that matter. I really do not know how it is suppose to act, but from everything I have read, not like it is.

I even contacted the supplier and he was adamant that it was not his companies fault and there was no way it could be anything but what it is labeled. He went on to say how he deals with tons of this stuff and if it was impure he would be getting complaints non-stop. However, if someone walked to the wrong barrel I dont see how a goof up couldnt be made.

Anyways, I am just trying to figure out what to do. I would rather not spend another 40 bucks on 2 micron aluminum if the oxidizer is to blame. Anyone have any suggestions or some way to test the perchlorate to rule it out? Thanks!

Please describe mixing procedure, batch size and scale used.

Bert,

I started using the diaper method and mixing up 3 grams. I use a lab grade triple beam scale. After mixing awhile it still seemed like there were little clumps of perchlorate. I tried igniting this and nothing.

Next, I mixed up the same size batch but I tried putting the perchlorate under a lamp for awhile and then putting into a mortar and pestel to break up any clumps. This time I put the mix in a pill bottle and rolled it back and forth for awhile. This seemed to mix the two with no lumps. Again, not much happened except for the occassional sputtering ignition mentioned previously.

I am at a loss. Again, any help is greatly appreciated!

Is the aluminum flake, granular, or spherical (atomized)? The particle shape has a large impact on its reactivity. Flake works best, granular works ok, and atomized doesnt work very well at all. Many people believe it has to do with surface area, but in reality, a spherical particle has much more surface area than a flake relative to its mass, but a flake will burn much faster and light easier due to a spherical particle's tendancy to absorb the initial heat of reaction, requiring more energy input to burn.

Use a thing called a 'Paragraph Break'. Thank you. NBK

If you are using a quality flake aluminum and finely ground KClO4, and mixing them well, there is no reason it shouldnt burn very rapidly. Safety is another concern when mixing flash, especially for someone who is new to mixing high energy compositions. The critical mass of this powder is between 20 and 50 grams, so mixing large quantities is not advised. If you have an accurate scale capable of measuring sub gram quantities of powder, mix 1 gram batches at a time, this will be more than enough to test the burn rate.

In my opinion it is the aluminum. Kmno4 will make good flash with crappy aluminum. I bet you have atomized, and I would bet it is more like 325 mesh. Where do you get it? Is it dark, grey, or silvery?

Try another test with your perchlorate and sugar. Does it burn violet? See how much KClO4 will dissolve in 100 ml of water at 20 degrees C. Let us know.

I have tested 325 mesh flake al and perc. And although it takes a few seconds to start, it burns rather fast.

I have no idea as to what the type of Al it is. It was bought off ebay. From what I had read I thought if it was 400 mesh or greater it would be ok for use as flash so I just bought 625 mesh that was a good deal.

The Al I guess could be called either gray or silver but its not very dark. I have a black Sharpie pen in front of me that has a gray/silver body and it is a couple shades darker for a reference.

I guess I read about how reactive flash is and how even in small quantities it is quite powerful and I have a hard time imagining a huge difference with different Al. To go from barely burning to almost exploding unconfined just seems like a long jump from going from something that is like flower to quality pyro aluminum. But I guess that could just be my inexperience with this.

Anyways, I mixed the perchlorate with sulfur and it did burn with a light violet color.

I dissolved 1.8 grams in 100 ml of water. BUT, I didnt have distilled water so it was just filtered tap water that goes thru a water softener first. And it was also a little warmer at about 25 C. I believe about 2 grams is suppose to dissolve in 100ml so I dont know if mineral content in the water could take up that 0.2 grams. There was also some insoluble mater in the perchlorate (maybe 2-3%?) and it is advertised as 'high purity' thru the pyro dealer and is suppose to be their top of the line perc.

One last thing is that I mixed up half a gram of permanganate (lab grade purchased from Fisher) and the aluminum (65/35) and put in a card board cup set with lots of tape. It pushed the two halves of the cup set apart and was probably about as loud as a legal firecracker but with a deeper 'boom' instead of a crack sound. So basically for a half gram it didnt sound all that loud to me. I guess this points to the Al as well.

Sorry this is so long winded. Just a little frustrated and trying to figure out the problem. Thanks!

PS. Anyone have experience with pyroaluminum.com? Also, any good uses for the aluminum I have? It works well with ammonium nitrate in exploding rifle targets. Would ball milling for a couple days do anything?

Its absolutely your aluminum, you have atomized. There is a HUGE difference between the different shapes of aluminum, and to a lesser degree the size. For example, a 2 micron spherical al particle would work relatively well for flash. A 22 micron spherical particle would be close to useless. Flake of either size would work well for flash. You were correct in thinking anything finer then 400 mesh would work, but you were not thinking about the shape. Fine flash grade flake al will be pretty dark.

I highly suggest pyroaluminum.com, I have bought from them. They have great powder, and you will see a huge difference. I personally would not mill the aluminum yoiu have, because you have access to the "real" stuff. Just use that aluminum for glitter, or other pyro. Or even as a small percentage in your new flash with the fine flake.

The solubility of your KClO4 is correct. However I asked you to use sugar for the color test as sulfur burns blue by itself! No matter though, your perc is not at fault.

Also, there is a person selling super fine mgal, which will kick the shit out of the finest aluminum. This stuff self confines at less then one gram in the open! It is incredibly powerful and requires extra care!! I do not know about sensitivity or stability. I have had a salute of this stuff sitting for extended time though. His email is: mark1ia@hotmail.com Please tell him Al sent you and you will get a the discount. I believe he is selling the powder for $29 a lb. It is VERY worth it. It is normally about 35$.

Either way you go, pyroaluminum.com or the mgal, you will be very pleased! Have fun and stay safe!! Post here or email me if you have any more questions.

Thanks for the reply!

I will order some new aluminum and I might try the mgal. I would like to use the safest combo so I might hold off on the mgal until I get a better feel for good flash.

Yeah I should have mixed up some more with sugar but I was going out of town and I already had some mixed up with the sulfur. I thought I remembered from chem that potassium burned purple but I didnt remember that about the sulfur. I had mixed the perc with sulfur to test its impact sensitivity. I put it on a steel plate and hit it with a sledge and it took a pretty darn good impact, but it ignited.

I'll try mixing with sugar when I get back in town just to double check and I'll also make an order with pyroaluminum.com.

I wish I knew a use for the aluminum since Ive got 10 lbs of the stuff. It is very impressive mixed with ammonium nitrate and shot with a rifle. I just dont have the best place to shoot and make that kind of noise.

Thank you for the help and also the lead on the mg/al!!!

If you have high explosives, the Al will work fine in those to boost power. High explosives are not picky at all about the Al you add, it will even work with Al turnings almost as well as powder. There is probably more info on this use of Al elsewhere on the forum.
I have heard that 30% Al in blasting gelatine is an incredibly powerful mixture, in the blasting gelatine thread on this forum.

If you're just into pyro I guess you're out of luck except for an occasional exploding target.


I've seen 0.1 micron spherical Al before, will this work for good flash? I've read about flake vs spherical before, but I have always wondered how well the 0.1 micron stuff would work...
I've always wondered, mostly because I was so amazed at how small the little particles of it are.
You'd probably send the whole bucket up as dust when you opened it lol :rolleyes:

I ended up buying the spherical 625 mesh Al from ebay as well (plans & kits unlimited, i believe). So far it hasnt proved to be all that effective, when mixed well 5/3/2 with KNO3/S/Al, it results only in a hot white flame that lasts approximately 1 second or so when about 2 grams are burned in the open.
USE
I recently got some KClO3, and was wondering if it would be conceivable to make a flashpowder work, perhaps in a 72/28 or so ratio. Is there some way to sensitize this mixture so that it will lower the ignition temp and burn faster without breaking the cardinal rule of mixing sulfur with a chlorate?
PARAGRAPH
I just hate to think that I wasted money on some lousy Al powder. (btw, on the website it has demonstrations of 70/30 KClO4/Al flash going off, and it seems to work quite well).
BREAKS
Thanks a bunch.

Chlorate is already one of the easiest to ignite, fastest oxidizers there are! Even using this very powerful oxidizer your flash will be shit. But you can add airfloat charcoal powder and have a decent deflragration. Don't even attempt to add sulfur.

You got ripped off if your sole intention was to use the aluminum for flash. So yes, you wasted your money. There are two things you can do: 1: Ball mill the aluminum until all the particles are milled to a fine flake. 2: Buy flash grade aluminum powder.

I think the demonstrations they have are made with high quality flake aluminum. Does it say that flash was made with the aluminum you bought? ;)


Chris: Sub-micron powders are so fine the shape would not matter. I am sure it would be great for flash. Where have you seen this? I hope not ebay!

Someone could try using better containment and stronger initiation. 625 mesh spherical is not suitable for small devices with light containment- But it works just fine with perchlorate and Sulfur or Antimony tri Sulfide for 1.3 aerial salutes containing several ounces (or pounds... don't tell the CPSC!). The lower reactivity & cost, and higher initiation energy needed are attractive to those handling large quantities in commercial production. It's also nice to not be covered in airborne Aluminum flake after mixing.

Someone who could legally do so and felt confident in handling larger quantities of flash might try this: Mix at 7:3:1 Perchlorate:625 mesh spherical Aluminum:Sulfur (or even better, Antimony Sulfide). Mix perhaps a 100 gram batch, not 2 grams... Understand that a salute built in this size or larger can easily dismember and kill. Get a section of thick walled cardboard tube such as a newsprint core, perhaps 3" in ID and 4" or more in OD and just long enough to contain the amount of flash to be used. Make end caps out of 3/4" plywood. Have your fuse go into a centrally located tube of 4 or 5 grams of fine black powder such as 3FG rifle powder, rather than directly into the flash.

After filling the tube and gluing the end caps on, take STRONG natural fiber string and soak it in wheat paste or watered down white glue. Wind the string tightly end for end over the tube many times so that the end caps can not easily be blown off. Allow it to dry, the string will shrink as it dries and make it even tighter. If it is to be used as an aerial salute, additionally paste several layers of strong paper over the whole thing, sealing it against lift gasses.

Some people have been said to add an additional 1/3 by weight or so of fast double based powder such as Bullseye to flash powder used in salutes of this type as well. The high temperatures and pressures produced inside these devices can cause high NG content powders to do surprising things.
Or give up on flash for a while and learn to make glitter stars, or high performance composite rocket propellants.

Ok, so I'm back with a different problem.

On al93535's advice, I bought 8 oz of 600 mesh flake magnalium on ebay in an attempt to get a more reactive flash powder.

After drying some KClO3 under a halogen lamp for a while and then grinding it heavily with a mortar & pestle for about 15 minutes, I weighed out 7.0g KClO3 and 3.0g of the Mg/Al powder and proceeded to diaper them together for approximately 5 minutes. After this I lit a small amount (.3 g?) with visco fuse and got a short lived flame that kind of hissed for about maybe half a second with a blinding white/purple flame. Not the "whump" or near self-containing "thump" I'd expected.

Any ideas on improving my mix?

Ok, so I actually kinda answered my own question.... Upon tweaking the ratios a bit, I found I can get a quite satisfactory thump when a small amount is ignited in the open.

50/50 KClO3/MgAl seemed to work well, but I'll fine-tune it from there.

Do you have any idea what your ratio of Magnesium to Aluminium is in your Magnalium? Assuming it is 50/50 Mg/Al then we can perhaps say....

2KClO3 + 5Mg + 5Al -> 2K2O +MgCl + 4MgO + 2Al2O3 + AlCl3

If there is a problem with it, please say so, I've only done Yr 12 Chemistry, so there is alot I don't know.

Now, using Mole Theory (it's perhaps blindingly obvious *wink*) we find that we need 245.0984g of KClO3 for every 256.435g of Magnalium, or in other words a ratio of 1:0.9557.

So, after all that, about a 50/50 ratio of chlorate to magnalium is about right *wink*. Try 5g of KClO3 and 4.779g Magnalium.


Damn, I feel stupid *laugh*. A good hint, that I've found has helped alot in my past is look at the site of the reaction. If you have melted metal left over, you used too much or didn't mix it well enough. If you have fused KClO3 over, then too much of that.

Have a nice day lman.

PS. This may be of interest for people http://www.vk2zay.net/article.php/85

PKUNLIMITED is also selling 1250 mesh spherical.. This is such a high mesh, it would work good for perchlorate flash wouldn't it?

Chris, very small aluminum particles like that tend to have a fairly high percentage of oxide in the mix. This doesn't mean they won't work but one may have to adjust for oxygen balance.

About the Mg/Al flash : it has more weight/ volume and therefore a higher energy density . Mg/Al is heavier than Al which surprised me.

You guys are Lucky living in the States ,because you can just buy your metal powders . I have to make my own. Because of that I learned a lot about them . Al powder suitable for making flash powder will start burning (without oxidizer) when it 'touches' a simple match flame. A teaspoon amount will take about 5 seconds to completely burn/react with the airs oxygen, giving a bright white yellow light. The left over should have a light grey to almost white 'color' . A deep grey left over indicates that an amount of AlO2 was present in the Al powder .

A deep grey left over indicates that an amount of AlO2 was present in the Al powder .

*wince* Al2O3.

Why would there be a difference in colour between "pure" Al2O3 and burnt Al? I'm just curious. Wouldn't any amount of aluminium that had been exposed to the air have some Al2O3 in it, and any aluminium that was burnt would be converted to Al2O3?

I suppose its possible that some of the Al didn't become oxidised, but I'm pretty sure that if your burnt Al doesn't look like pure Al2O3 then there may be some impurities from your grinding process...

Aluminiumoxide coating for protection of for example aluminium profiles is a deep black and very hard material. Burned Al looks very different ,so it must be a different oxide.
Aluminium in contact with air wil always oxidize . The amount of oxide can vary however,depending on moist, heat etc.

Thanks for your calculations, Alexires, and indeed I believe my magnalium to be 50/50 MgAl, but I dont know if all those products you listed would actually be formed. I was under the impression that you would end up with pretty much just KCl and MgO and Al2O3. That being said though, your ratio of 5 g Mg+Al and 4.779 g KClO3 sounds like it could be a winner, I'll just have to try it out. Peace.

First of all, lman.

I concede that it is highly possible that the products may indeed be different that what I stated, but it was what occured to me first. I suppose it made my working out alot easier as it all worked without having to stuff around alot *grin*. Have a few goes yourself and work it out. Naturally, if you get different mole ratios then a little experimenting will be in order to see which is the most accurate.

atmosphere1 - Maybe I missed that in chemistry 101, but I'm absolutely certain that Aluminium has only one oxidation state, and that is 3
(http://en.wikipedia.org/wiki/Aluminium) (http://en.wikipedia.org/wiki/Aluminium)

I cannot fault your observation skills, and I can understand that without research, you may indeed reach the conclusion that there are different oxides, but you are wrong.

Unless it is something else, the oxide coating on the outside of aluminium window frames is a dull silvery colour.

No idea where you got a "deep black" from. Are you perhaps thinking of Iron? Iron has multiple oxidation states, producing FeO, Fe2O3 and Fe3O4. FeO and Fe3O4 are black...

How do you call those pieces of Aluminium ment for cooling transistors and other electronic components ? Sometimes they have a black coating , this is anodized aluminium.

I guess there must be an other reason why burned Al looks different than the anodized aluminiumoxide oxide.

I have to add something molar or mass ratio isn't the same thing. So let's first clear up what 50/50 means? About equation...it is good attempt to solve this problem numerical way, yet it has wrong formula- should it be MgCl2 - so I didn't even bother to check did you solve it correctly. It is made on assumption of 50/50 molar ratio. When it comes to industry they are more prone to express mass ratio which mean 5g Mg + 5g Al = 10g MgAl. Anyone who know what is the molar ratio of Mg/Al in MgAl?

Anyway there is open question of products of that reaction and by using some thermochemistry tables we could try to calculate which of the posible reaction route would give highest energy output. It won't give true equation of that reaction, only it maximum limit, but it is something to start with.

AlO2 mistery is a hoax coming from some kewlish sites...I never understood how did they asign Al with oxidation state +4 (or +2 if we assume peroxide which is even less likely) - maybe some tried to write aluminate anion covering the surface of metal. Only way that powder can have grey ash behind is from incomplete combustion IMHO. Are those traces of C, Al or something else makes no difference. Colour isn't substance...or same substance has different colors depending on the way it is obtained...I think Sb2S3 change it's colour with ageing in solution upon precipitation. Reason for incomplete combustion of powder mixtures are...countless, or to big for this post.

Urgh, I read the wrong line. It took me a few goes to balance the equation and I read it wrong, and got a little mixed up while copying the MgO and wrote MgCl instead. Balls, now nothing works. Ahh well.

I did a little bit of reading on Magnalium, and it said that the total magnesium added could range from 5% - 50%. That was why I said to assume it was 50/50 (in my mind that means for every one Aluminium atom, there is one magnesium atom).
Sorry I didn't make myself clear, or triple check my equations *sigh*.


Atmosphere1, go to wikipedia.org and search for anodising. It will tell you that the oxide layer is Aluminium Oxide (Al2O3) and that the different colours are simply dyes.

Again, my apoligies.

Urgh, I read the wrong line. It took me a few goes to balance the equation and I read it wrong, and got a little mixed up while copying the MgO and wrote MgCl instead. Balls, now nothing works. Ahh well.

I did a little bit of reading on Magnalium, and it said that the total magnesium added could range from 5% - 50%. That was why I said to assume it was 50/50 (in my mind that means for every one Aluminium atom, there is one magnesium atom).
Sorry I didn't make myself clear, or triple check my equations *sigh*.


Atmosphere1, go to wikipedia.org and search for anodising. It will tell you that the oxide layer is Aluminium Oxide (Al2O3) and that the different colours are simply dyes.

Again, my apoligies.

I already knew that , the the oxide layer is Al2O3, but without dyes it is black . Al in the air wil always loose its shining surface and appear more dark becuase of a very thin black layer of Al2O3. When I burn fine high quality aluminium powder in the air the left over appears more white alsmost like Mg0. I was just wondering why it appears so different.

Al2O3 is always white. I pack damn thing into columns very often and know what I talk about. Layer of Al2O3 on Al surface can disperse light better making surface looking little dim, but I never seen it black or even heard such thing. Yes it is usualy dyed but I don't know is that neccesary.

Thats what I thought FUTI, I always imagined it about the same colour as burnt Mg.

Atmosphere1, was it really necessary to quote the WHOLE post?

What we are trying to get at is that it SHOULDN'T appear so different. If its black, it's either not Al2O3 or your Al is contaminated with something.

Particle size is important for color of powders, so I guess thin and thick layer won't have same appearance but I would be puzzled to see it has marked difference in visible spectrum. There were recent thread on forum about anodizing aluminium, I should read it to find out.

Since I started this thread I just wanted to add what I found.

It was definitely the aluminum powder. I ordered some from pyroaluminum.com and it is a darker color, more like a graphite color.

It now burns very rapidly unconfined. A gram confined in a two piece cardboard pyro cupset sounds about like a .45 ACP. It is loud but not quite what I expected from the flash horror stories I have read.

If a standard chinese firecracker only uses 50 mg I figured using 20 times the amount of powder would be a little more substantial. I guess I need to work on my confinement if Im going for more 'boom.'

So if you are having problems with flash and are using a known oxidizer, I would say take a hard look at your aluminum.

I now have 10 lbs of the original stuff I bought to try and find something to do with. Exploding targets made with NH4NO3 are quite impressive if anyone wants to find a use for poor al powder. Guess I'll try ball milling some and see if I can get a more reactive product.

Thanks for the posts that said to look at the aluminum!

Smoakie I got some of the same stuff off e-bay (I know this because it's really the ONLY Mesh 625 Al that can be found on eBay. I mixed up a KNO3/S/AL
(50/30/20) flash that totaled 30g and it was all but worthless. Confined it in a 3.25" tube with 1/8" wall and SOLID epoxy end caps... created one hell of a smoldering fountain nothing more. Due to the pressure generated in decomposition being weak due to the size of the AL.

How is that 2micron Al from pyroal.com?? While I'm a newbie on the forum's I've been working with pyro for 5-6 years now and have NEVER attempted using anything that fine as for the fears of spontaneous ignition in a 70/30 mix for aerial salutes. I found a website saying how they'll mix up 70/30 in 100G batches in a Ziploc bag!! Playing with death IMHO on that front, I diaper anything I mix but have no idea the sensitivity of 2micron (if truly 2micron that’s in the 6000 mesh range). Any insight into that level of sensitivity is appreciated!!

There are some other people selling 600+ mesh non-atomized (nonspherical) Al on ebay. I bought some, a lb for $15. Tomorrow I will be trying it out in kno3/s/al flash. I'll update as to how it goes :)

TA911 please update when you get it in!! I'm getting ready to relist and sell some more KNO3/S/AL and go back to KCIO4/AL mix that I'm used to using...

KCIO4 isn't hard to come by (for now in the US), but I was looking for a new burst charge for mortars. That said any Mod's or people who love to mix flash know of a 2micron powder and it's sensitivity?? From all the charts and books I have that's like 5000-6500 mesh!!

Below is an old quote from Gerald Hurst, posted previously at RogueScience, concerning the use of coarse aluminum in flash powder. For those unfamiliar with Hurst, he has a chemistry Ph.D. and a lifetime’s experience with explosives.

“I also use sodium nitrate based flash powder, but no milling is required. I simply mix relatively coarse Al (<100 um)* with sodium nitrate (about 0.5 mm)using about 10% excess of the Al. The mixture is about impossible to ignite with flame, even with a gas torch you can heat a long time before it starts burning - so it is safe to handle. A blasting cap is required to set the powder off and the critical diameter is about 2 cm. I usually load about 100 gram charges. **

The above flash powder gives a long lasting fireball and a nice mushroom shaped cloud of smoke. You can really see the bright fireball rise, before it goes off. Also, the air is filled with aluminum sparks. After the extremely bright illumination, it is hard to see anything for a while.”

* 100 um = 0.1 mm = 0.004 inch = 140 mesh
** 100 grams @ density = 2.0 and diameter = 2 cm, gives length = ~15 cm.

The shape of the aluminum particles is not specified, but in any case, higher pressure can make coarse aluminum, which is cheaper, easier-to-obtain and safer, burn fast enough to function as pyro aluminum.

The fact that sodium nitrate can function as an oxidizer for flash powder, without sulfur, amazes me.

Perhaps a flash “primer” using fine aluminum would have the same effect as the blasting cap.

I confess to never having tried any of this, not even in my dreams, but it seems to me that vigorous initiation may offer new options in the manufacture of flash powder.

Dexfurax :

The aluminum seems to be of high quality, at least how it acts now using the same KCLO4. It doesnt seem overly sensitive to me but I have not mixed very much yet and have not performed any friction or impact tests. I will do so and report back.

So far what I have done to test it is to make a few salutes just to see how it behaves. I have been using pyro cardboard cupsets. I add 0.7 grams KCLO4 and 0.3 grams of the aluminum. I then seal up the cupsets (one side had a fuse preglued in). Once finished I then shake the salute holding the fuse to mix the contents. This way I figure there should be no problems with static because of the cardboard and there is no friction because everything is sealed and stationary before mixing.

This just seems like a safe way to do it to me. I will be using it in rockets as a report so I dont know if I will be able to do it the same way or if I will need to premix it.

Thanks for the reply on the Al. I'm going to pick some up this weekend online... My other stuff from e-bay that started this thread (the 625 from PK) I've ballmilled to around 1000 mesh and relisted... ;)


As for mixing, the conflicting reports I find are "Flash is so deadly when mixed in 50G or higher quantites due to the mesh of the some Al powders)... that said as

long as your air salutes are below 50G (and 50g of a GOOD mix will be VERY loud) then I'd say you may want to ziplock it for a quick mix before loading...


Something I have yet to try and will and report back as it's been mentioned to be safe in the forum as safe. If anyone missed it, 70g of KCLO4 and 30g of Al

powder, standard ziplock and a can of "Static Guard"... Spray the bag, fill it up, GENTLY mix in hand... done... I'm a bit weary since I ususally diaper everything to

avoid anything happening but need something better with less cleanup... Are you getting your KCLO4 from skylighter?? I usually will use other sources or make it.

Their price does look pretty good compared to most others...

I also bought some KCLO4 from ebay, just waiting for it to arrive and I will be mixing up some flash.
<p>
As for my kno3/s/Al flash, well, I mixed up a ten gram batch today and I put a gram or two in a duct tape pouch to test it out. It seemed pretty good, it's the first flash I've ever made, but it popped the duct tape and made a bright "schwoomf". Later I tossed the rest and lit it unconfined.

It didn't seem too fast, lasted over second, but it was damn bright.. Like Mg ribbon :eek: This could be due to my sulfur being only 90% stuff for gardens from lowes. I'll compare it to 70/30 Perchlorate/Al soon as I can. By the way I diapered it for about a minute.

Also, nice idea reselling your Al the price may well skyrocket to $35.. Saw it happen before.. Crazy ebayers :D

I just set some 3g-4g salutes of the cheap Pk-unlimited "atomized" Al with some good KClO4 and got a nice report.

Now, same amount with some of the Al from exchem is much sharper, but my point is when mixed correctly even the cheap "crap" Al from ebay works as it should. I suspect as the amount goes up the difference will start to fade...

What, precisely by weight, was your mixture?

You are correct. The finest flake Al may be reserved for the smaller devices, cheap atomized Al is quite useable for large aerial salutes with substantial containment.

Use the least reactive ingredients needed to get the desired effect. It's cheaper as well, of course.

What, precisely by weight, was your mixture?

I made 8 of the smallest salutes I could using the "cheap" aluminum from pk-unlimited. Each held about 2-2.5g of FP.

I measured simply, electronic scale with a paper cup on top. I zero'd it out, then added 6.6g of aluminum (slightly aluminum rich).

Then I zero'd it out again w/ the aluminum on it, and added 15g of KClO4.

Diaper mixed on tissue paper, loaded in salutes. One side hot-glue, the other side a wad of paper and hot glue to seal it, some had fuses out the sides, some had fuses through the top. I made a small jig of aluminum to do this..

NOW! what may have HELPED (a TON) was the Al they advertised was "1250" mesh that I bought, as opposed to their "625" mesh Al they also have for sale. I have some of that, too, but havn't tried it yet.

+++++++++++


Grammar, and clearly constructed sentences are your friend, and ours. :)

Kingtaling,

That's EXACTLY what your benefit is. Your using the 1250 mesh he sell's... Not the crappy 625 Atomized...

I mixed it by weight in typical 70/30 ratio's and got nothing more than a few sparks and alot of left over Al powder since the surface area sucks on that powder (the 625).

Also tried a formula of KNO3/S/Al at 50/30/20 by weight with the 625 and the same result, a nice shower of spark, defrag speed was around 2.5 seconds for a 4.5g batch. At around 1.8 sec/g that speed is WAY too slow IMO to make any type of salute, air or otherwise.

The only way I can see to make it work to other users of PK Unlimited 625 powder is to actually work at it.

A 25-30g charge of 70/30 in a thickwall cardboard tube, solid (hot glued endcaps) and perhaps a 2-3g BP inital charge to get it working. This should increase the internal temps and pressure ALOT and create a much faster burn.

F*ck it, save yourself the time and get some better (albeit) more expensive powder from E-bay or skylighter.

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How about editing

your own posts to

remove the gap

between every

fucking line?!

Since I started this thread and it looks like some others have bought the PK unlimited crap 625 mesh, I thought I would add some more of my experience.

70/30 perc- pk crap did nothing for me. Didnt even begin to burn.

So I bought some real aluminum from pyroaluminum.com. This is the real deal. 70/30 mix, light confinement, big boom.

I was reading Shimizu and he states with perchlorate, the loudest composition is 64-23-13 perc-al-sulfur. I also read that the sulfur lowers the ignition temp. So I got to thinking...

I mixed up 1 part dark pyro al, 1 part crap pk al, and 1 part sulfur and mixed it well. I then substitued this for aluminum in a standard 70/30 mix (yeah I know it isnt quite the above optimum ratio). And I got a report that is almost as loud as with just the dark al.

I would say this new mix is not quite as loud and a little higher pitch. I used 2/3g in a salute to test and to me it sounded almost exactly like a 40 cal or maybe even a 45 gun shot. The standard mix, same size, to me is a little more deep, about as loud as a 45 but a deeper boom than any gun shot.

So if you bought the PK unlimited al and afterwards got some good dark, here is a way to use the PK stuff and also conserve the good stuff by only using 1/3 as normal.

If you like loud noises and like to shoot guns and want a use for the PK unlimited al you might also want to check out this thread (http://www.roguesci.org/theforum/other-explosives/3772-exploding-targets.html) as it works in these exploding targets perfect for me.

Just wanted to post a follow up with some new info.

Smoakie, I hope you stocked up on the Al from Pyroaluminum.com. He's out of business.:( Damned shame too, it's (was) good stuff.

hst45:

I noticed his website was down but I didn't know if he was just having problems with it or what. Are you sure he's out of business?

I only got 2 lbs and I would have liked to get at least 2 more. But, with my new mix using the sulfur and the cheap Ebay al, that 2 lbs will stretch to 6 lbs, which will make 20 lbs of flash.

I really only use flash for the report in rockets so I should be set for a long time. I think I am more concerned about KCLO4 disappearing so I think I'm going to try to order a bunch of that for now.

Smokie,

I heard that the CPSC ran a ration of shit by him and he quit. Too bad too.

I think you're right about stocking up. It fear that it's likely to get worse, and more expensive.

From what I've heard pyroaluminum is not out of business, the guy who runs it is just going camping.:rolleyes:

Give him a few more weeks, I'm sure it will be up and running again.

Just a quick update on pyroaluminum.com. The site comes up, but it's not what it used to be. :mad: It's now some referral site to aluminum products, and unfortunatly none look like aluminum with "energetic" potential.

Just a quick update on pyroaluminum.com. The site comes up, but it's not what it used to be. :mad: It's now some referral site to aluminum products, and unfortunatly none look like aluminum with "energetic" potential.

That means the Domain is not registered to him anymore.. It is basically for sale. I think this is little more than "camping"

Inquiring about the domain 'pyroaluminum.com'

Plus I emailed him with no reply....

When those referral pages come up it usually means that the domain name has been purchased but the site hasn't been built yet, or it is under construction.

When I make changes to my web page the same kind of page shows up until it is finished.