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Posted: Sun Apr 01, 2007 11:02 pm
by frankrede
Just use a propane bottle with a npt adapter to pressurize your reservoirs.
I so want to build a flame thrower.
But my recent brush in with fire was a bad one so I might have to build a water gun that doubles as a flamethrower.

Posted: Sun Apr 01, 2007 11:37 pm
by pyrogeek
Ok, if you want to use propane to pressurize the chamber, here's what you do. Either get an Acme nut off a grill, or buy one. Or, get a torch head, or buy a disposable tank adapter. Then, attatch a 1/4 NPT ball valve, then a compressed air regulator to that, attatch a hose to the output of the regulator, and you are good.
The disposable tank would probably work best, since you could have constant pressure, and replacing the tank would be cheaper than refilling a CO2 cylinder. Plus of course, you don't have the initial investment of a CO2 regulator and such since a compressed air regulator will be much cheaper.

Posted: Mon Apr 02, 2007 12:08 am
by frankrede
Why would you use a regulator?
Propane runs at around 90 psi.
That sounds right for pressurizing his tank.
Unless we wants to go lower.
Btw, propane and compressed air regulators=?
I have heard that they can damage them

Posted: Mon Apr 02, 2007 9:39 am
by Modderxtrordanare
Would using Denaturated Alcohol as a fuel be a bad idea? I hear gasoline will eat through PVC tanks, but I don't know about using the alcohol.

Posted: Mon Apr 02, 2007 10:33 am
by zeigs spud
Modderxtrordanare wrote:
zeigs spud wrote:okay don't give an attitude cuz it is only a bomb if YOU screw up and don't make it right, hell the military uses propane somtimes as the compressed gass to push the fuel.

obviously you shouldn't make one yet cuz you don't fully understand them. let me help you, the compressed air is safe becuase the flame cannot go back into the chamber becuase it the nozzel is too small for it to shoot back in and the fuel to air ratio is way too off to do that. under normal circumstances that shouldn't ever happen. so don't be a smart @$$. :D
I wasn't trying to give off a bad attitude, but you said to use compressed air, not propane. Propane would be safe, because there wouldnt be any oxygen in the system to cause an explosion.

It wouldn't matter how small the nozzle was, a flame could still trace up it. However if I used regular air, it would actually have a chance to trace back and explode, even if it is a poor combustion. Id rather have a 0% chance of something on my back exploding, than a 10% chance.

I really didn't mean to offend you whatso ever, sorry. :oops:


Edit: I've seen that link, I even posted it in my original post. :wink:
lol hmk srry for flmain a bit my bad.

but again it COULD go up the nozzel, the chance is extreemely small and it woulldn't have any oxygen in the tube going to the chamber, thats prettymuch how peizo lighters work, so under normal circumstances (such as no cracks, leaks, ect. ) it shouldn't go back up. so air again is the cheapest way to do it. mabey it is a lill unsafer but barely. many throwers (home made that is) us air.
Modderxtrordanare wrote:Would using Denaturated Alcohol as a fuel be a bad idea? I hear gasoline will eat through PVC tanks, but I don't know about using the alcohol.
don't quote me on this but detured alchohol shoudl't eat through the pvc, and it works pretty well as a fuel, i don't think that is would but do a test, get a peice of pvc, weigh it to the nearest 100th of a gram and the set it in the alcohol for a day or two then leave it to dry. after it is fully dry weigh it again and see if the alcohol ate at it or not.

Posted: Mon Apr 02, 2007 9:43 pm
by Killjoy
Modderxtrordanare,
I use denatured alcohol which works great and has no effect on the pvc what so ever. I would use gasloline because someone on spudtech showed it has no effect on pvc, but im not taking that risk.
I also use a check valve to prevent back flash (or what ever its called), but the chance of it exploding would be extremely slim because the flame would have almost no chance of making it through the fuel line into the main fuel tank.

Posted: Mon Apr 02, 2007 11:23 pm
by Modderxtrordanare
Did you just use fuel line from the bottoms of the tanks to the gun?

Could I just run the hose coming from the tanks into a small diameter section of metal pipe and on the other end of that pipe put a nozzle. That would essentially form the gun part, correct?

I would of course spruce it up and add a handle and some valves to control the flow and whatso.

Posted: Tue Apr 03, 2007 12:00 am
by Killjoy
if i understand what you are saying, then yes you are correct.

Posted: Tue Apr 03, 2007 9:00 am
by zeigs spud
Modderxtrordanare wrote:Did you just use fuel line from the bottoms of the tanks to the gun?

Could I just run the hose coming from the tanks into a small diameter section of metal pipe and on the other end of that pipe put a nozzle. That would essentially form the gun part, correct?

I would of course spruce it up and add a handle and some valves to control the flow and whatso.
yea you can, i sugest on the handle put a propane torch for your piolet light.