Starman, Recombining water in the quantities I am contemplating isn't very dangerous. Maybe a bang, at worst I blow some PVC apart (which is why you do everything remotely). I know what I'm doing. Propane, on the other hand, carries risks. A leak in a propane tank would be more dangerous than a leak...

Yeah, but if you crack open a hand-cranked flashlight (the ones that advertise to never need batteries) and just use muscle power, you have free H2 and O2 (well, you have to pay the water bill). Gotta be crafty when you are cheap.

Truthfully, if you just want to watch and hear H2 and O2 go boom, slip a small plastic bag (1 quart) over your electrolysis beaker and seal it with a rubber band around the beaker. Wait until the bag loosely fills with gas and just light the plastic bag with a match... BOOM.. ok you're done... Roll...

so I should evenly space all my wires, not put them in pairs? (I'm not so sure I need more than one sparker on the scale I would build anyway) And I'd love to know what materials I should have to use. I don't want to build it out of PVC to find out that it's too weak. I should probably build it on a...

SO do you think this would work?

Anything I'm missing?

Materials?

Ragnarok, I wouldn't touch that with a 20 foot pole. Maybe using pressure, but never throwing them at fires. If I got the pressure up to 100psi, I'd be scared to set it off unless I had a blast shield. I might have to try a cannon, but it'd be weird to construct. I think I'd need to have one long ba...

Maxus, you will probably never get the chance to use it. It's really cold, and really dangerous. Thats why you always see ice on the sides of rockets on the launch pad, the fuel is frozen. I'm not sure they ever use solid stuff (I think there are better fuels) but it's possible. I want to hear if an...

:) I'd rather have a fire I know is small and is gonna be out shortly than a large fire that I have to sit around and watch burn for 6 hours because my gun is sitting in it. Thermite is a bad choice; I was just throwing it out there that it works, and does have a few advantages over a log (although ...

Oh, and I'll go ahead and say it: Thermite is a STUPID idea for this application.

Yeah, but if you are planning on just dumping the gun into a fire, this is a little smaller and managable. I can see the problems with my method though.

Has anyone ever made a cannon using H2 and O2 as fuel? If you don't know, you run electricity (I think it has to be DC, but I may be wrong) through water to separate the molecules which turn into gas. You then put those 2 gases together, introduce a spark and they recombine and unleash massive amoun...

If you want water at 700 degrees celcius, thermite is about the only way I know of. If you want Fahrenheit, thermite is a little overkill. There are many types of thermite, ranging from tank killers to welders. Some is just hot enough to melt steel but not vaporize it. Look into that. It's also pret...

If you still don't have a heat source, you could consider Thermite, assuming you have the equipment to make/handle it. That might be too unstable for your needs though.

Some types of thermite are made to burn through tank armor though, so be careful.

I have a feeling I won't be satisfied if I don't make a piston, even if my first try isn't up to par.

EDIT: I added a pic of a simple design of a piston, which I don't see too much difficulty in making.

ok, I got it. Thank you very much.

I also found this picture, which helped me very much.

Whats the difference?