SpudFiles

I am planning on making a special effect for a large paintball scenario we are planning.

Basically I need to create a loud bang and a big fire ball.

Now, I have seen some guys a long time ago fill their pneumatics with propane and exhaust it over a flame to create some good results. But I need to create a loud bang as well.

I was thinking of making a combustion cannon that has a "barrel" filled with liquid propane. The barrel would have to have burst disks on both sides to contain the propane, using liquid propane would decrease the overall size of the device. When the gas mixture in the barrel combusted it would rupture the burst disks and push the liquid propane out of the barrel as well as igniting it. The rupturing of the burst disks should make a loud noise.

Sounds good in theory but is it possible?

Why not just put an ignitor in a large bucket, seal the top with stretch film and inject an appropriate amount of propane into it?

If you're going for the plan with the two burst disks, use gasoline instead of propane! Gasoline will give you a larger flame and more black smoke.
G's from the Dutch, Tom

I have a hard time beliving a simple combustion will burst the burst disc with ~100PSI pushing on it from the other side.

I have a hard time beliving a simple combustion will burst the burst disc with ~100PSI pushing on it from the other side.

Try a pneumatic (burs disc) with a barrel full of gasoline or flour(this would be harder)

EDIT: hmm.... i did edit, guess i accedently pressed submit twice when posting first one. deleate above one please =)

Sounds dangerous to its surroundings, hmm maybe something like this

skip too 1:10

I guess I'm not a mod, but rp181, please just edit your post instead of double posting.

what about a small amount of black powder that ignites gasoline in a barrel.

would make a loud bang and lotta smoke and flame, but i dunno about how safe it'll be.

I've made pyrotechnics by digging a 1 ft x 1 ft hole in the ground, lining it with a plastic bag and making a charge out of duct tape and black powder and placing that inside the hole and filling the hole the rest of the way with gas. That produced about a 15 ft fireball and a loud bang. but i'm guessing you want something at an angle fired out of a barrel, maybe use the same idea with steel pipe?

if you get a simple pneumatic between 20 & 60 psi (i'm guessing), put a bunch of flour in it and get a fueled & lit rag on a metal rod attached to the barrel it should make a good fireball

You can use non-dairy coffee creamer, with a black powder (is this allowed outside the context of spudguns?), or even combustion propellant, althought you may need to use some petrol to aid ignition in a simple combustion

BP method

you do know that flaming/fireball/incinerary projeciles is not allowed to be discussed on this forum dont you so just watch your posts

Why not just put an ignitor in a large bucket, seal the top with stretch film and inject an appropriate amount of propane into it?

I am not sure if that will be big enough, I will try it out though.

Guys, sounds like lots of pyromaniac fun but a little dangerous. I wanted to go with a combustion because it will be easy to electronically activate. I think propane rather than petrol because propane is safer and easier to use, not as volatile as petrol.

I guess a pneumatic filled with propane and a burst disk could work. If I had a spark strip on the other end of the burst disk would it be able to ignite the propane flowing at a high speed?

Any burst disk design thats large enough in diameter will probably do the job of giving the bang, but for the fireball, a few ml of liquid propane, ignited and squirted up in the air would do.
I said squirted, not shot. A pneumatic burst disk noisemaker along with a liquid propane squirter + igniter could do it.

But you ofcourse can always just do it together, with the propane between burstdisk designs.

I think someone on here did something like this with a simple pneumatic the just made a ridicuously large ball valve cannon then attatched a 4in steel pipe to the end facing up, then he filled it with sawdust and put a little petrol on the top lit it and released the pressure I remember the fireball being enormous, but I dont think there was to much of a bang.

For a bang you will probably need a burst disk.