"Safe" flash powder

[azure]

I don't know if this is the right forum to post this but it does concern safety regarding the mixing and handling of flash powder.

 

I've done quite some experimenting with flash powder that has most of it's metal content replaced by pentaerythritol and i'm quite impressed with the results so far.

 

I feel more comfortable mixing up a batch of this flash powder then milling a pound of BP

 

http://www.youtube.com/watch?v=jkVvB6J__u0

[Mumbles]

By definition you need the metal for flash, otherwise you have glorified whistle mix. It all still works for salutes if you only care about the boom of course. Static and friction are generally considered to be the big dangers with flash. If a mix gets exposed to that much fire, you probably have bigger problems. I can't speak for pentaerythitol, but some organics are more sensitive to static than others or even mixes containing metal fuels.

 

As a guess, I'd imagine it behaves somewhat like lactose. Both contain external hydroxyl groups, and have somewhat similar melting points. Lactose with chlorate or perchlorate is somewhat surprisingly sensitive compared to some other things. There aren't a lot of extremely similar compounds to compare to, as most are liquids at RT.

 

I'm not sure I would consider it any safer than flash, or at least no safer than whistle mix. If someone considers flash too dangerous on it's own, it may be a sign they probably shouldn't be making it anyway.

[NightHawkInLight]

I wasn't sure how to reply to this post. It looks safe"ish" in the open, but once it's confined, like all salute comps it is quite capable of causing harm. If confinement is all it takes to become explosive, it should be treated the same as flash would, as if it will explode violently any time it is treated with disrespect. It may take only a small portion to be under confinement from the end of a dowel or tool for example, which if ignited may act similar to a blasting cap to the rest of the comp. I would need to do some experimenting with the stuff myself to really get to know how it behaves. It's not your typical pyro comp.

 

If someone considers flash too dangerous on it's own, it may be a sign they probably shouldn't be making it anyway.

 

I agree with that to a certain extent, but I think most everyone would like to make flash and pyro comps in general safer to work with if they could. That doesn't necessarily mean they're unqualified to use them. I understand what you mean though.

[jerronimo]

Try the binairy method of mixing flash, Ned over on passfire has a good description of the procedure.

 

You actually mix the flash in the container (salutecasing) so you avoid being exposed to open flash.

This is the safest way I know off, and now only use this method for my 3 inch salutes and they perform great!

 

Once complete flash salutes can be handled pretty rough, they ship thousands of them from china to all over the globe.

[Mumbles]

Unfortunately the binary method doesn't work for all salute applications. I'd never dream of using it for salute inserts or bottom shots.

[50AE]

I don't trust the binary method, it makes me nervous that the flash hasn't been homogeneously mixed.

[asilentbob]

As well with very densely packed bottom shots, you can't really pour the individual chems in and expect them to mix.

 

PE tends to be pretty rare, may want to not burn it up in something so trivial as flash. Just saying.

[fredhappy]

As well with very densely packed bottom shots, you can't really pour the individual chems in and expect them to mix.

 

PE tends to be pretty rare, may want to not burn it up in something so trivial as flash. Just saying.

 

 

 

Although I can understand binary mixing for bottom shots/inserts is not going to be effective, I employ the binary method for my spherical salutes, and am very pleased with the results.

 

The trick is not to overfill your salutes, just a little over half full of flash is just about right. I also add 10 % ricehulls as a fluffing agent, and coat the walls with spray glue and then roll on the titanium.

 

You cannot fill up the salutes completely with the binary method. The mixture needs some space to integrate well. A 3 inch salute will hold about 60 grams of flash , and a 4 inch about 120 grams. They are extremely loud and always well mixed in my opinion. I very much like the idea not having to diaper these amounts of flash in the open.

Edited November 30, 2010 by fredhappy

[asilentbob]

Sometimes when you want closer to a thermobaric effect you don't want that air space, and you want your flash dense. Very fuel rich, lots of gaseous products.

 

Can get some very large impressive booms. So much bass that your ears don't ring, even relatively close. I prefer to feel it in my chest, not with a sharp painful crack in my ears.

[pyrokid]

Sometimes when you want closer to a thermobaric effect you don't want that air space, and you want your flash dense. Very fuel rich, lots of gaseous products.

 

Can get some very large impressive booms. So much bass that your ears don't ring, even relatively close. I prefer to feel it in my chest, not with a sharp painful crack in my ears.

 

 

Would you care to elaborate on that, bob? I like a good deep salute now and then.

[jerronimo]

Nitrate (slow) flash can be used when a deeper sounding salute is wanted, it needs good confinement to work well.

Im always amazed that a formula that hardly burns in the open can produce such loud salutes, it produces lots of gas thats for sure.

[anapogeetoofar]

According to the PATENT , terephthalic acid is preferred over pentaerythritol. It also claims that this mixture outperforms conventional flash powder (in terms of peak pressure at least).

[pyroshell]

I can not find any testing for friction,impact or static. If someone can find this it might be helpful just to know. Also according to the guy who posted the video it is twice as powerful. I have no idea how much truth there is to that statement.

[FlaMtnBkr]

I have used a similar formula using TPA. I have tested small amounts by hitting and scraping with a hammer on a steel plate and it doesn't seem very sensitive. I don't have a good way to test for static. It works good for small inserts but larger aerial salutes I will stick with the binary method. It is used extensively by the military (contractors) who make various simulators, flash bangs, and some other devices that use flash so it must be fairly safe.

 

TPA also works pretty good in a non toxic military smoke. You can get it from Cracker here on the forum.

[Vrizla]

I came across this post recently and instantly became intrigued by this new formula. I did a quick search to find some TPA to experiment with; thus far I have came up with limited sources. There is a Japanese based seller on eBay listing 99% pure TPA with no details on particle size:

 

http://www.ebay.com/itm/Terephthalic-acid-99-1kg-Laboratory-Reagent-/330548470244?pt=LH_DefaultDomain_0&hash=item4cf63961e4

 

link to store: http://stores.ebay.com/Reagentshop-01?_trksid=p2047675.l2563

 

Most of their products use a stock photo that looks like a clear liquid but I don't believe it is. Does anyone more familiar with TPA know if this product is suitable to experiment with following the information and procedure listed in patent.

[Nessalco]

Save your money. You can pick up TPA from Hunter (CaliforniaPyro) or Cracker, both for far less than $30/lb.

 

TPA is a widely available product, in the industrial sense. It is used to make PETE plastics. The worldwide annual manufacture is in the millions of tons.

 

Kevin