Flamethrower!

A place for general potato gun questions and discussions.
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Pete Zaria
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Fri Oct 27, 2006 2:21 am

I'm waiting to know from the mods if it's OK or not.

I'm hesitant to post any actually usable plans. If any of you screw up and burn down a house or torch the hell out of someone, I'd feel kind of responsible.
At the same time, if I don't post any plans, you'll probably blow yourselves up attempting to build a flamethrower anyway. So I'll let the mods decide.

BLB, Pimp, Drac, PCGuy...?

Peace,
Pete Zaria.
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Fri Oct 27, 2006 6:27 am

Nitros Oxide is not a flammable gas either, it is an oxidizer, merely aiding, by providing oxygen, to a combustion process..........

Be afraid, very afraid.........

Why not just use acetylene? I'm sure a nice 25/75 mix with O from dads torch set will speed your quest to permanently remove the neighbors cats eyebrows just fine. :-)

E
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SpudStuff
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Fri Oct 27, 2006 8:34 am

Why don't you do this through E-mail, PM, or IM.
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Spyider
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Fri Oct 27, 2006 11:15 am

what did i do what through ?

and killagorrila99 if you could find the link itd be much appreciated lol thanx

spyider
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singularity
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Fri Oct 27, 2006 11:37 am

now i might be a complete retard who has been dealing with explosives for years now but... arent flamethrowers suppose to use napalm?!?! and pressurizing the fuel tank with NO2 is just about the most retarded idea ive ever heard! keep the fuel tank a pure fuel enviornment as to prevent fire from going back into it and causing a massive explosion in the tank straped to your back (well at least if you plan to make this portable). or you could have some sort of daul chamber tank...

<img src="http://i78.photobucket.com/albums/j85/i ... /flame.jpg">

use your brains people!!!
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sgort87
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Fri Oct 27, 2006 11:46 am

Okay, let's backtrack a bit here.

First off, nobody is going to die. Flamethrowers are child's play. Don't be stupid and you are fine.

Use gasoline. It's cheaper and readily available. I don't know where you guys got the idea that denatured alcohol was cheaper because it's about $12 for 2 quarts.

Use compressed air because it's the easiest source and cheap as hell. Propane works but it is a waste and makes everything cold as fuck. That's not good. N2 is expensive. Yes, compressed air obviously has oxygen in it but if you watch your flame you are fine. All you have to do is wait for the stream of flame to turn into a roaring cloud then you shut it off and refill your tank. Keep the air input near the top and the gas output from the tank at the bottom. Flame cannot travel through pure gas and it wont.

As for plans, I would say a DESIGN would be fine, if your purpose is for us to review it and discuss. But if your purpose is to post exact plans on how to build, what to use, and where to find the things, then no. There's no need to explain in detail how to make these. If you can't figure it out then you shouldn't build it. Never build something you don't understand.
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Spyider
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Fri Oct 27, 2006 12:20 pm

i understand it i was just wondering about a "compressed gas fuel" on what to use because air + gas under pressure = a bomb lol thats not that good... the main thing was what fuel to push the gas out would be the best... if you went to that site i posted on the first page thats bassicly what i want to make.

ill repost it

http://science.howstuffworks.com/flamethrower3.htm
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Pete Zaria
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Fri Oct 27, 2006 12:24 pm

Sgort,
I must respectfully disagree on a few points.

It's true that gasoline actually is cheaper, but it's more corrosive and gasoline vapor is explosive while alcohol is just highly flammable. I really recommend using alcohol or diesel instead of gasoline. Plus, you can buy paint thinner or mineral spirits (which is mostly denatured alcohol) in quart cans for like $2.
Second, using compressed air seems suicidal to me. Pressurizing fuel and air in a sealed container is known as a bomb.

My design uses propane to pressurize the tank. You obviously know why, but for the people that don't, if there's more than about 10% propane in a gas mixture, it won't ignite. Therefore, over-saturating the chamber with propane makes it impossible for the flame to travel back up the "barrel" into the tank and ignite. Also, propane canisters are $3 and produce 90+psi, making them very convenient for pressurizing the tank with. Also, it means you don't have to haul around a compressor or bike pump.

My design (not really plans, as it doesn't include a parts list or step-by-step instructions, just a drawing) includes a ball valve at the top of the tank for pouring in the fuel, a system to pressurize the tank using propane, a safety valve, a back flash arrestor in the "gun" part to ensure that a flame (or pressure spike, for that matter) can't possibly reach the tank, and a pilot light system. I'm toying with the idea of a glass tube that would run the length of the tank (but outside the tank) so that you could see the remaining fuel level. My design also includes a 125psi pop-off valve in case of overpressure or any potential tank fire, a pressure gauge, etc...

I'm guessing total project cost will be around $75 to do it right. The tank will be made of an oval-shaped "doughnut" of PVC (two sections of 4" PVC, about two feet long, joined by two 90's at each end, with the gauge and etc... tapped where the fittings overlap the pipe).

I'll do a CAD drawing and post it tonight, if none of the mods object before then.

Peace,
Pete Zaria.
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singularity
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Fri Oct 27, 2006 12:35 pm

do you people relize how easy it is to make napalm, think for a secontd what is naplam... thickend gasoline. as to not break form rules i will give a word which obviously has absolutely nothing to do with thickening gasoline... styrofoam
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Pete Zaria
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Fri Oct 27, 2006 12:45 pm

I'm sure everyone on this forum could figure out how to make crude napalm, but it's kind of useless for a flame thrower. The military ones use an oil mixture with a more "syrupy" texture. For our purposes, a liquid fuel such as alcohol or diesel will work fine.

Peace,
Pete Zaria.
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Spyider
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Fri Oct 27, 2006 1:07 pm

yea not liike it would shoot jelly balls out lol. itb be like a big jelly gun then lol. i dont even think that napalm would work and itd be almost pointless to even make it. what are you goina really do with it ? throw it on a brick wall and watch it go sizzel ooo aaa.
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Fri Oct 27, 2006 2:07 pm

Greek fire would be great to lauch out of this
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sgort87
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Fri Oct 27, 2006 6:25 pm

I have 3 napalm "candles" sitting right next to me now actually...

I do have t agree with you about a lot of points Pete, but I insist gasoline is the most efficient way to go. I do like propane as a pressurization source but it does get cold and sometimes even gets ice buildup. Probably better anyway though.

For the sake of safety, I should be saying propane all the way, so I'll go with agreeing with you.

Funny that this topic came up. I'm working on fixing the thrower up for tomorrow's Halloween party.
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frankrede
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Fri Oct 27, 2006 6:43 pm

Hmm, I can make a crude and dangerous flamethrower using a fire extinguisher and a propane torch mounted on it.
Current project: Afghanistan deployment
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Spyider
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Fri Oct 27, 2006 8:22 pm

well if you are worried about the pvc getting cold and cracking under cold pressure dont wory because im about 95% sure ima use steel anyways just to maek it look more realistic yes i now ittle way more on the backpack mount but im willing to have that for the safty of cracking AND ittle look better when done... anyways, Pete Zaria how bout them plans ? lol
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