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Flamethrower. Our plans. Help? and more.

Unread postPosted: Thu Jun 25, 2009 1:01 pm
Author: mik3v
Okay so two friends and I are making a flamethrower.


These are the plans we have edited from elsewhere and created this prototype.

Right now we are having trouble with our Blow gun assembly that is supposed to act as our trigger for releasing pressurized fuel into the gun and out the barrel. The blow gun we bought is pressure rated to 90 PSI but is leaking at only 80. When we first assembled it, it would hold back all the pressure of the tank and not release pressure until we pushed the trigger. However, now it is slowly leaking without pushing the trigger.

I have posted about our flamethrower before and have gotten great feedback as well as extra precautionary parts and things to watch for and how to be as safe as possible.

Also, many people have strongly advised that we use an inert gas to pressurize our tank so we don't explode. However, we are worried about the cost effectiveness of using anything else since we currently just use an air compressor to pressurize it now.

Some of you have even said not to use propane, which was our second choice, and to use CO2 instead. If we were to use propane, how would we get the propane into the PVC tank and pressurize it? What parts would we need?

Actually, more puzzling to us would be how we would use CO2 to pressurize it...? How would we get CO2 into the tank...?
Currently, we have a schrader / air valve that we got at an auto store and threaded and welded into the PVC tank. This was easy and we can just use an air compressor and fill it like we would a tire.

SO, we have the fuel tank assembled and the gun almost assembled but we haven't housed the whole gun in PVC yet since it is not quite ready and is leaking...

In addition, we used the proper pvc weld, pulmbers solder and weld, then in addition went over EVERYTHING with JB weld. It works miracles. haha :D

Well, thanks for looking at our project in the making, and we appreciate all constructive feedback.
Michael, Troy, and Alex

Unread postPosted: Thu Jun 25, 2009 1:10 pm
Author: twizi
use an inharit gas like co2 or somthing nonflamble

ps i would research more never compress gasoline with compressed air

get a reg at lowes to prezuries the tank with co2

Unread postPosted: Thu Jun 25, 2009 1:23 pm
Author: chenslee
Your pilot light is going to be a sooty mess since you are not mixing the propane with air.

use this and a blowtorch for the pilot light:

...and put this on the propane tank in the back:

You will also need some npt fittings and a hose or pipe between the two.

Most flammables will spontaneously ignite at some temperature and pressure. Whatever you are squirting, I'd check it's properties.

If it were me, I'd be squirting rubbing alcohol. Getting burning alcohol on you is survivable; gasoline... not so much.

Unread postPosted: Thu Jun 25, 2009 1:30 pm
Author: Carlman
I dont think so guys...

Our rules clearly state that we are not to discuss incinary projectiles, I would class this as such.

Its a spudgun forum for christs sake!

Take it to theopia.

Unread postPosted: Thu Jun 25, 2009 1:35 pm
My "constructive feedback" On this...( :lol: )

Don't build it...Maybe build a similar design that fires water,
Also, i can't enlarge on computer I'm on, but the fitting look like DWV.

-Compressed air is a big NO-NO for gas.
-On a hot day, propane will be pushing the pressure range safety for the pipe.
-For CO2 you'll need an expensive regulator, and you don't know "how to...[whatever simple thing it was even]"
Besides it's already leaking???

If you're set on it though, I suggest you build something you can sell AND save some money so when you burn your parent's house down, and go to jail for arson and pyrotechnics (maybe manslaughter(?)) until you're 21 you can buy them a new one and order necessities ,you know underwear, candies, toothpaste,soap and don't drop it either).

Oh, I also suggest you get laid before you build it so when you get all burned up wrinkly skin and can't get girls at all atleast you'll have had ONE...

BTW, I'm not a mod but, since when is flaming gas not an incendiary???
Oh, if you do build this and what I'm sure will happen happens, If your parents try to sue SpudFiles, : I will probably hunt you down... :twisted:

Unread postPosted: Thu Jun 25, 2009 1:59 pm
Author: cannon monkey
sorry about this idk if you finuged it out yet i just skimmed but my c02 tank with remote line i just push the female quick connect on the schrader valve and it fills
it all looks good
but if you use that schrader valve u can use air or c02 like i said before just need a remote line

Unread postPosted: Thu Jun 25, 2009 2:18 pm
Author: Carlman
Guys seriously, as soon as a mod sees this its gone, all your doing is making a bad rep for yourselves.

Unread postPosted: Thu Jun 25, 2009 2:18 pm
Author: mik3v
Here are some pics showin what we've done so far.

The Fuel tank: (all our PVC is pressure rated to 220 PSI, used pvc weld, and JB weld over the top)

Top of the Tank: 300 PSI guage and fill port.

Bottom of the Tank: Valve and Hose barb to connect a pressure rated tube to the bottom of the gun.

Bottom of the Gun: pressure rated to only 90 psi... the blow gun is currently letting pressure go out of the barrel..... might have to replace the blowgun...

End of the Gun/ Barrel: smallest hose barb we could find to keep the pressurized fuel to a small stream

Base of pilot light: cut and extended with copper tubing then re-welded.

End of pilot light: re-welded the propane torch tip to the copper tubing, works GREAT.

Unread postPosted: Thu Jun 25, 2009 2:38 pm
Author: Pilgor
don't go past 120 psi

Unread postPosted: Thu Jun 25, 2009 2:41 pm
Author: mik3v
Pilgor wrote:don't go past 120 psi

we havent and wont. we were planning to hypothetically use it with fuel at 110 psi to 60 psi. only in between.

thanks thought :)

Unread postPosted: Thu Jun 25, 2009 2:52 pm
Author: jeepkahn
why don't you go to the local farm store and buy a frikkin' garden sprayer and a book of matches... Not to be an @ss, but get a grip and go play on and save bandwidth that could be used for spudding...

Unread postPosted: Thu Jun 25, 2009 3:08 pm
Educational for you vid Here
That's why I suggested you get laid before you build it.
Also why I mentioned what will probably happen... :(

Unread postPosted: Thu Jun 25, 2009 7:01 pm
let me guess you wanted to make it more exciting by building it out of PVC?? :shock:

will it burst and and set me on fire or not...?? muhahahahha!!!

Unread postPosted: Fri Jun 26, 2009 1:14 pm
Author: mik3v
jeepkahn wrote:why don't you go to the local farm store and buy a frikkin' garden sprayer and a book of matches... Not to be an @ss, but get a grip and go play on and save bandwidth that could be used for spudding...

No thanks. This is called the NON SPUD RELATED discussion. ill discuss NON SPUD related stuff if i want. and some people on here have done this before.

Update: We've replaced the blow gun that we were going to use as our trigger with a more reliable and heavy duty ball valve. In addition, we just added a check valve to prevent backsuck or whatever you guys call it.
The JB weld is just about dry, hoping to pressurize up to 110 PSI and then put everything underwater and test for ANY leaks. Almost positive we've repaired them all. If all goes good, we will retest it with water again, if all goes good then.... We will house everything in the the pvc and fill it with Great Stuff that will expand in the PVC and then add the caps and plugs to the open ends that have holes drilled out for the barrel and Pilot light and help hold them in place. Then, fire :)

Thanks to those of you with positive feedback and criticism and helpful, safe knowledge.

Unread postPosted: Fri Jun 26, 2009 2:34 pm
Author: ramses
I am convinced they are dwv elbows. I'm not a mod, but you really shouldn't tell someone with nearly 1000 posts to GTFO.

also, all the discussion of nitro and the E&W forum should probably stop. That said, he would be kicked off the E&W forum in a
second.[/mod impersonating]