Heat and pressure ARE related

[DYI]

still, does anybody know a material with a really low temperature autoignition point??

SiH₄ has an autoignition point of ~21°C in air, but you'd have one solid combustion product (SiO₂) which would tend to reduce ballistic efficiency. B₂H₆ autoignites at ~38°C, but suffers from the same problem. Aerosolized EGDN or PGDN would both decompose at just over 100°C, but that would be a terrible idea (all things considered, the previous two are just as terrible, but more proper to discuss on Spudfiles).

After that, we have diethyl ether at 160°C, and monomethyl hydrazine at just under 200°C. Pure hydrazine is in there somewhere as well. All of these are liquids at room temperature, but all but hydrazine have a flash point below room temperature. I have yet to come across a gas which would be suitable for your purpose.

[inonickname]

Carbon disulfide autoignites at 90 celsius, and is volatile enough that some rubber onto the walls with volatilize into a gas quickly. Tongue in cheek, you could also use white phosphorous (don't ).

A lot of things suitable will often be high explosives- and as such aren't suitable to be discussed here.

[DYI]

Surprised I didn't think of CS₂. It would be a decent candidate here. I considered white phosphorus, but the reaction products would make for a terrible propellant gas. SO₂ isn't that great either, really...

Tongue in cheek...

After my previous post, did you really need to include that?

[Technician1002]

You could use a small amount of ignition gas to ignite a traditional Propane Air mix.

[inonickname]

Surprised I didn't think of CS₂. It would be a decent candidate here. I considered white phosphorus, but the reaction products would make for a terrible propellant gas. SO₂ isn't that great either, really...

Tongue in cheek...

After my previous post, did you really need to include that?

Not only would it be a terrible propellant gas, it would be incredibly dangerous and destructive. A cloud of white phosphorous/phosphorous pentoxide/phosphoric acid would destroy most barrels, chambers, and you when the gigantic cloud blows your way..

And EGDN in a spudgun? What kind of idiot would use high explosives as propellants in a gun

[caspar97]

And EGDN in a spud-gun? What kind of idiot would use high explosives as propellants in a gun

I'm sure there are people out there who would, knowing today's generation, so I really wouldn't recommend joking about it.

@Techinician1002, That is what I am going for. A little of say CS2 and the regular propane air mix[/quote]

[Ragnarok]

I'm sure there are people out there who would, knowing today's generation, so I really wouldn't recommend joking about it.

The joke is that there are people who would and have on this forum, and that people like that are currently involved in this very conversation.

Poking fun at daft things you or others may have done in the past is an odd form of humour, I know, but it's common enough nonetheless.

[Technician1002]

I think some theatrical flash paper may be used. It us not explosive like flash powder. It is often used to ignite the high temperature flash powder in magic acts. Paper to eject the powder and for the yellow fire and a small amount powder for the smoke cloud. This prevents a closed container explosion which is why stage flashpots are relatively silent with a whoosh instead of a bang. Flash paper burns with almost no smoke.

This post is on flash paper as kindling for air propane, not stage pyro.

[inonickname]

Flash paper is made in the same way as NC propellants, and is essentially the same (chemically, it is) so discussion here would be fairly limited. You'd probably get away with using the smallest amount (so it doesn't contribute a significant amount of energy- no different to BTB's percussion cap hybrid or the new steel wool/BP ignitor the guy who owns fear made).

Flash paper will decompose at ~160 degrees celsius (if you can get some, drop a little above a going gas stovetop- you'll be surprised how high it pops at) and energy will be roughly 2700 j/g. If you go this way, use as little as you can. Under pressure (not spudgun pressure, explosive pressure) NC burnrate goes up FAST- you want so little NC that the gasses from it won't actually increase the chamber pressure too much.

And as Rag pointed out, the joke is people posting here have done it

[Technician1002]

I do remember it ignites at a much lower temperature than flash powder. The glow plug used on stage hand held flash-pots (fire from fingertips) is difficult to ignite it without flashpaper.

And yes, this is a discussion on ignition sources, not propellant.

A match is an ignition source. A 1000 match heads is not.
Same with flash paper, small ignition amounts only.

[Selador]

This is how a fire piston works.

People carry a fire piston with them when they go wilderness camping.

You place a piece of combustible material, like a piece of charred cloth, or a particular kind of moss, on the tip of the piston.

There is a little cup there, to hold it.

Then you ram the cylinder down on the piston as hard and fast as you can.

The fast compression within, creates a spark in the material, and you use that to start a fire.