Flash Powder

[pyroman]

My friend and I are pyrotechnical enthusiasts. We have recently looked into making flash powder with seven parts potassium perchlorate and three parts aluminum powder. Just how sensitive would this mixture be?

[mississippichem]

pretty sensitive. This mixture has the potential to explode spontaneously The finer the aluminum powder the easier it will detonate. A you fairly familiar with redox chemistry? If so, I'll explain why quantitatively; if not I won't bore you.

 

Either way, be careful with this mixture. I tend to work with a good degree of caution and would not want to store this mixture. I would prepare this mixture and detonate it on the spot.

NASA used to use a similar mixture for their solid fueled rockets, but they stored it in a "polymer matrix" to prevent an ignition event from getting out of hand.

[pyroman]

I wouldn't say that I'm really familiar with redox chemistry, but i do get the general idea of it. Is there any simple thing that i can do to make the mix more stable, and maybe even storable?

[DJBruce]

pretty sensitive. This mixture has the potential to explode spontaneously The finer the aluminum powder the easier it will detonate. A you fairly familiar with redox chemistry? If so, I'll explain why quantitatively; if not I won't bore you.

 

You won't bore me.

[mississippichem]

You won't bore me.

 

Alright:

[ce]so \ E^o=2.86 V \ for \ 3KClO_4 + 8Al -> 4Al_2O_3 + 3KCl[/ce]

 

[math]\Delta G^o = -nFE^o[/math]

 

[math]where \ F=96485.338 \ Cmol^{-1}[/math]

 

[math]so \ \Delta G^o = -221 \ kJmol^{-1}[/math]

 

I don't have the standard entropy values for some of the species so I can't calculate total enthalpy but i'd be willing to bet that entropy makes only a small contribution and this reaction is quite exothermic.

 

Is there any simple thing that i can do to make the mix more stable, and maybe even storable?

 

Must be kept cold and in static free conditions, but dude, I really wouldn't want to store this stuff. The only way to ensure saftey is not to store it.

[pyroman]

Allight, yea thats good to know haha thanks, appreciate the help

[rogerxd45]

is there a different flash powder that would be more stable?

but even then i would agree not to store it. its easy enough to mix on the spot

 

a thing to keep in mind when storing a low explosives (when you NEED to)is to do it like how they store smokeless gunpowder.

 

i reload ammo and the containers i buy my powder in are made to easily split in half and the cap is made to pop off easily in the event the powder ignited. this prevents the build up of pressure so you have a large flame instead of a bomb.

 

I also keep my powder containers away from each other so if one did ignite then i would only have 1lb max instead 5-10lbs, it is also kept in places that a quick large flame would be less likely to cause a continual burn which could lead to burning my house down.

 

but flash powder burns a LOT faster then smokeless powder so even if these steps were followed the outcome would be most likely be worse

[pyroman]

Ok, so i got the chemicals and mixed them in the right ratios in with the proper 'diapering' technique. i used .7g of KCLO4 and .3g of aluminum powder. yet for some reason, it didn't work... like, at all. my concern is the aluminum. I've been reading everywhere that you want to use dark german pyro aluminum, but its much more expensive than, say, an aluminum bought off of Ebay. Is the dark german the only aluminum that will work or am i just retarded and doing something wrong?

 

Also, I've read that another way to make flash powder is with KNO3, sulfur, and aluminum. Is this a better/more stable mixture? If so, what are the ratios?

-Thanks

Edited August 5, 2010 by pyroman

[mississippichem]

I'm not sure about the German pyro-aluminum, but the aluminum has to be finely divided, and must be mixed with the potassium perchlorate in the correct stoichiometric amount. I gotta run to work, but I'll edit this post this afternoon and show you what I mean.

[rogerxd45]

your problem is most likely the aluminum,

 

what you want is stuff like this (not my sale and am in no way endorsing that seller it was just the first on the list)

http://cgi.ebay.com/Real-German-BLACKHEAD-Aluminum-Powder-Eckart-5413-1-lb-/290478339692?pt=LH_DefaultDomain_0&hash=item43a1dbb66c

 

ekhart 5413 seems to be the # choice but there are plenty of other options

 

like this

http://cgi.ebay.com/Indian-Blackhead-Aluminum-powder-1-pound-/290472380560?pt=LH_DefaultDomain_0&hash=item43a180c890 (its about half the price so honestly i would try that first)

 

keywords to look for are Indian Blackhead and German and of course "pyro aluminum"

 

be safe and please report your results