Sciencemadness Discussion Board

Armstrong mix that does not explode on impact. why?

jundeed - 20-11-2017 at 04:29

I made an armstrong's mixture with 70:30 match heads (ground to powder) and red oxidizer, but it doesn't seem to explode on impact but ignites when I press a hot needle (not red hot) on it. Any thoughts on what am I doing wrong? or did I create a not so impact-sensitive mix?

Aqua-regia - 20-11-2017 at 05:31

Maybe the mixture is wet. Carefully dry it by oven 110 degrees.

Rhodanide - 20-11-2017 at 06:02

Quote: Originally posted by Aqua-regia  
Maybe the mixture is wet. Carefully dry it by oven 110 degrees.


I'm sorry, but that sounds like a really bad idea

Bert - 20-11-2017 at 07:35

What do you mean by "red oxidizer"? The oxidizer for a match head is in the match head composition itself.

Perhaps you mean the substance on scratch pads of match boxes- Which is glue, ground glass and a small ammount of red Phosphorus.

Where did you learn about Armstrong's mixture, and what do you think it is composed of.

mackolol - 20-11-2017 at 10:47

Making armstrong's mix isnt good idea. If reagents are pure and dry if explodes after mixing. Its extremely sensitive and blows on open area. And even without that why to waste phosphorus that is very useful element. It didnt explode because, i think matches have too small amount of chlorate and phosphorus.

Rhodanide - 20-11-2017 at 11:02

Quote: Originally posted by Bert  
What do you mean by "red oxidizer"? The oxidizer for a match head is in the match head composition itself.

Perhaps you mean the substance on scratch pads of match boxes- Which is glue, ground glass and a small ammount of red Phosphorus.

Where did you learn about Armstrong's mixture, and what do you think it is composed of.




Hey, congrats on your 2000th post lol

Aqua-regia - 20-11-2017 at 12:56



I'm sorry, but that sounds like a really bad idea[/rquote]

He wrotes about pulverised match head + oxidising material on scratch pads of match boxes. This can be drying gently in oven. I done it much, if I was a young guy.

Armstrong mixture is different. This is mix of potassium chlorate + red P or S, extremly sensitivity to shock, friction and flame, hence I believe that it would be a good idea to avoid working these primary explosives.

Bert - 20-11-2017 at 15:42

The match head composition is perhaps 40% Potassium chlorate, with adjuncts like Sulfur or sulfides as fuel, various carbonates and oxides to control acidity and burn speed, fireproofing to prevent the match stick from glowing after being extinguished, glue and dye.

The scratch pad has a small ammount of red Phosphorus along with the glue and abrasive, it only serves to a sensitize the chlorate composition, not as a primary fuel.

The chlorate, Phosphorus and Sulfur are way too diluted and out of proportion to behave like Armstrong's mix. You wouldn't want this in your pocket if it COULD behave like Armstrong's.

I have seen some do the lab work to separate the extra fuel and dilluent ingredients, then they make something which behaves quite like Armstrong's...

It is a lot of work for a small amount of composition, probably just enough to wreck your hand when it does what Armstrong's has done to EVERY person I know who made some. Which is to unexpectedly and violently go KABOOM! while being handled

[Edited on 20-11-2017 by Bert]

markx - 21-11-2017 at 03:20

Ahh...the fun of playing with the material from matchheads! Brings back quite a heap of memories and emotions from the childhood :)
As far as I can remember the dry material from safety match heads when handled without inclination to reckless stupidity behaved as quite a "safe" impact sensitive mix on its own and without any additives. It took some premeditation to get it going from impact alone. Nowadays formulations may be diluted down to a level that may make this impossible altogether, but to be honest I have not tried any of the old "stunts" lately.

I also remember that the toy gun report caps/strips and confetti salutes of my childhood times were based on real red P+KClO3 Armstrong mix and this stuff was really sensitive to the level of high absurdness. The salutes, when kept in very dry conditions, were truly sporting a feather trigger and they could go off from just dropping one out of your hand or slightly bumping it against an object.
Despite all of this we still managed to keep our eyesight and digits in tact, but in retrospect I must say that the phosphorous based mixes are definitely something that I would not advise to touch, let alone make for fun.

woelen - 21-11-2017 at 04:53

I agree with Bert. Real Armstrongs mix is insane stuff. I wanted to show my son how this mix can be ignited with a magnifying glass and sunshine.

I intended to make a tiny amount, by putting a spatula full of KClO3 on a dry concrete tile (outside in sunshine). I put a little powdered red phosphorus on it. Next, I took a little dead and dry twig from a tree, which I intended to use for carefully mixing the KClO3 and phosphorus. It never came to mixing, let alone doing the experiment with the magnifying glass :o
At the instant I push the twig into the small pile of phosphorus on KClO3 it explodes with a fairly loud THUMP sound and many very hot small droplets of molten KClO3 were sprayed around, producing several painful tiny burns on my hand in which I held the twig. This is my only experience with this mix, at least I demonstrated how sensitive this mix is ;)

Fortunately the amount was very small (tens of milligrams) and the damage was just some tiny burns on my hand. I must not think about what could have happened if this was gram quantities instead of tens of milligrams.