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[New to per/chlorates] Safe combustions with ammonium perchlorate?


Conure

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I recently got access to AP by mistake (wrong items in order) and I wonder if I could have some use of it. I have not used chlorates or perchlorates before since my main pyro interest is thermites.

 

I have red that AP is particularly risky stuff that can explode with many mixtures and is absorbed through the skin. Apparently using Al as fuel results in a loud flash and any organic substance will give an explosion. Yet many pyro compositions with AP involves organic stuff like gum.

 

What are some safe fuels to use with AP that will not go boom or bang? Just burn intensively. Can I use sugar, iron, silicon or Al flakes? Will it make toxic smelly smoke like from sulfates or iodine?

 

Answers appreciated.

Edited by Conure
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I bet you mean ammonium chlorate, not perchlorate, when you talk about such sensitivity. Ammonium perchlorate is commonly used in rocket propellant, strobe fuel, and color stars with high purity. It's finicky to work with, and should never be used around chlorates, because the very dangerous ammonium chlorate might be formed. AP stars shouldn't be primed with nitrate primes, because ammonium nitrate can form and make the stars unignitable.

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It's funny. They link an MSDS for AP, which only says that AP is a skin irritant.

This is true of just about any solid salt. The MSDS also has guidelines for exposure, but you must temper that information with the fact the those guidelines are made for workers with constant daily exposure, not the occasional use in hobby fireworks.

Edited by davidh
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Pyrodata is notoriously incorrect

I see. I thought pyrodata was a decent source of info. Could you give some advice in using PA? Like what fuels will result in explosion and can I use sparklers to ignite mixtures with it. Some sources say organic fuels and most metals will cause explosion.

Edited by Conure
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One of the NASA propellant mixtures is AP and aluminium powder with a rubbery polymer binder as an additional fuel. It burns quickly but doesn't usually explode.

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I see. I thought pyrodata was a decent source of info. Could you give some advice in using PA? Like what fuels will result in explosion and can I use sparklers to ignite mixtures with it. Some sources say organic fuels and most metals will cause explosion.

 

I think there's an important difference between a mix that "can detonate" and a mix that "causes detonation." The latter would be something that contains incompatible chemicals that could react and cause spontaneous combustion--luckily there are not too many of those, at least not many that would commonly be used by a sane person. Like JV said, the major incompatibility for AP are chlorates.

 

The other big reason to be careful with AP is that unlike most oxidizers it can detonate on it's own, and its sensitivity increases the smaller the particle size. That doesn't mean AP just blows up, it means that if somehow initiated through improper handling, a fire, etc., it can blow even if it's not mixed with a fuel. Adding metal fuel just spices up the party.

 

The fuel for strobe rockets uses AP and MgAl. When pressed in a rocket it doesn't explode (usually :D ) but loose fuel will go off like flash powder. Just one example of a mix that can explode, but isn't necessarily going to explode. I hope that makes sense.

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I think there's an important difference between a mix that "can detonate" and a mix that "causes detonation." The latter would be something that contains incompatible chemicals that could react and cause spontaneous combustion--luckily there are not too many of those, at least not many that would commonly be used by a sane person. Like JV said, the major incompatibility for AP are chlorates.

 

The other big reason to be careful with AP is that unlike most oxidizers it can detonate on it's own, and its sensitivity increases the smaller the particle size. That doesn't mean AP just blows up, it means that if somehow initiated through improper handling, a fire, etc., it can blow even if it's not mixed with a fuel. Adding metal fuel just spices up the party.

 

The fuel for strobe rockets uses AP and MgAl. When pressed in a rocket it doesn't explode (usually :D ) but loose fuel will go off like flash powder. Just one example of a mix that can explode, but isn't necessarily going to explode. I hope that makes sense.

 

Very nice info thanks. I just red that sugar or charcoal can make AP decompose exothermically and "mild explosions occur above 240c."

 

Looking at pyrodata.com I see there are compositions with AP that includes magnesium which I thought would result in explosion. Strange.

 

Anyway I was thinking of using AP with strontium carbonate and some organic fuel like red gum (or maybe silicon) to make red fire.

 

Can AP work as a substitute for KClO4?

Edited by Conure
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Modern formulas rarely use magnesium because its reactivity with water makes it difficult to work with and leads to mixes with relatively short shelf lives.

 

I have seen some red lance formulas that AP and strontium carbonate, though I doubt they would work well for color stars since they're typically slow burning.

 

I doubt AP would be a good substitute for KCl04, and I'd be wary of making substitutions. I am not a chemist nor am I terribly interested in experimenting with or developing compositions, I find a known safe and functional formula and use it. I'd recommend anyone new to pyro do the same, especially if they don't have a good knowledge of chemistry.

 

I hope my earlier comments didn't seem as though I was suggesting AP and AP mixes aren't dangerous. AP is a powerful oxidizer and explosive, as are many AP mixes. I just meant to point out the importance of understanding what is dangerous about a given chemical or composition, and the difference between an unstable mixture and a sensitive or highly reactive mixture.

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I just want to point out that that is what happens when you mix AP and aluminum........then confine it in a salute.........then ignite it. The same thing would happen with potassium perchlorate. It's basically just an expensive flash powder.

 

I would avoid mixing AP and metals for now if I were you. AP is not in itself overly dangerous or hard to use. It does have a larger than average list of incompatible materials. Mainly it is incompatible with potassium chlorate, potassium nitrate, and a few metals. Most organic fuels are fine. I will note that it is largely incompatible with magnesium though. It will rapidly degrade magnesium if the metal not properly pre-treated. MgAl isn't as bad, but does have the potential to degrade.

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I would avoid mixing AP and metals for now if I were you. AP is not in itself overly dangerous or hard to use. It does have a larger than average list of incompatible materials. Mainly it is incompatible with potassium chlorate, potassium nitrate, and a few metals. Most organic fuels are fine. I will note that it is largely incompatible with magnesium though. It will rapidly degrade magnesium if the metal not properly pre-treated. MgAl isn't as bad, but does have the potential to degrade.

 

What about iron as fuel, too reactive as well? What does 'degrade' mean in pyro context, oxidize?

 

I read some more about the saftey of AP and I find things like "severe explosion hazard, explodes at 380°c" and "extremely explosive in the presence of flames and sparks" and "may explode under prolonged exposure to heat or fire". Are these exaggerations? How do you use an oxidizer to burn things if burning it results in explosion. :s

 

How to best mix AP with stuff? When I make thermite I use a glass bottle and steel spoon. Should I use a 1m stick for AP stuff?

 

Also, what kind of gasses does AP produce with common fuels? Is it toxic smelly stuff?

Edited by Conure
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  • 4 months later...

From my calculations it should be easy to convert AP to KP. Where I live it is not possible to get chlorates/perchlorates but It seems I found a way to get some AP and KCl is very easy to get here. Will try it soon I hope...

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  • 4 weeks later...

So when burnt releases hydrogen chloride which mixed with moisture/water makes mild hydrochloric acid. (Eyes) so don't go breathing in the smoke directly.

Make sparklers...

4/1/1. Ap, hexamine, and steel 40-100mesh or brake turnings etc.

Mix powder and pour loose in a cardboard tube and attach a stick enjoy a epic effect of branching sparks like never before

Edited by pyrojig
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