Flame Thrower > Real One

Meaningful discussion outside of the potato gun realm. Projects, theories, current events. Non-productive discussion will be locked.
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zeigs spud
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Mon Mar 19, 2007 1:57 pm

yeah that is hella for a wiper.
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Benster
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Tue Mar 20, 2007 11:33 am

A just a quick note on the discussion of whether or or not it is safe to use propane to pressurize your fuel tanks, When I worked as a propane heater tech a year ago, one of the few interesting things that I learned is why flame doesn't travel back through the piping that brings the propane to the heater, its because there isn't enough of a oxygen to propane ratio (25:1 being optimum, as us metered guys know :D) to create even an incomplete burn, (where you burn so much more propane then oxygen that the propane doesn't fully ignite, burning real slow, and releasing a LOT of carbon). to go off kinda on a tangent to educate those of you who may not know, the way a propane tank works, is that the propane is compressed so much so as to turn it to liquid, it is then pumped into a container suited to contain its pressure, leaving about 15-20% of the container empty, in this area, some of the liquid boils into a gas at the top of the tank, and this is what is released when you open the valve. Now that we know that, back to the question, isn't the propane gas likely to explode when it mixes with the small amount of air at the top of the fuel tank it is pressurizing. No, be cause to properly pressurize the tank you usually run a straight, unregulated line from the propane tank to the fuel tank with only a shut off valve in between, so as the gas rushes into the fuel tank, the liquid propane is boiling as it expands creating a higher level of gas that fill the previously empty area. the creates such a ridiculously lopsided fuel to oxygen ratio that is completely unable to burn at all due to the lack of of adequate oxygen. You are more like to have a pressure related explosion due to using a fuel tank that cant handle the 175+ lbs of pressure propane gas han reach on a hot day then an explosion from you propane and fuel ignitiing in you fuel tank.


p.s. sorry for the novel :)
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imjustpk
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Tue Mar 20, 2007 11:52 am

Good point Benster. I remember my physical science teacher taught us that oxygen is needed for fire by taking one of the gas lines in the lab, cranking it up and lighting a match to it. He said their was no chance of an explosion because there was no air in the supply line, the end result was a 4 foot flame shooting across the classroom. Later that month he taught us how to make moonshine… I miss that man.
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zeigs spud
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Tue Mar 20, 2007 1:51 pm

lol yep thats what i alreay said, just long and deep into detail thanks :D
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imablackskater
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Tue Mar 20, 2007 4:41 pm

I found this awesome site that teaches you how to make a flame thrower with some pipe and a blow torch

*Link removed, unsafe construction/instructions*
Image
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zeigs spud
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Tue Mar 20, 2007 4:50 pm

DANG!!!! that is a great site! i gota make myself one of those lol. thanks for takin the time to look for somthing like that!! :P
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joannaardway
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Wed Mar 21, 2007 4:37 am

I saw that ages ago, and was wondering when it would be linked to.
Novacastrian: How about use whatever the heck you can get your hands on?
frankrede: Well then I guess it won't matter when you decide to drink bleach because your out of kool-aid.
...I'm sorry, but that made my year.
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zeigs spud
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Wed Mar 21, 2007 5:32 pm

i failed to mention with a lil research that the first flame thrower video, the flame thrower IS a PVC thrower. it doesn't look like it but you can see i you pause it when he takes it outa the truck that it is pvc.

idk why i didn't see that earleyer, real ones have a rounded tank end. hmmm yea just throwin that out there. :D
luke
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Fri Mar 23, 2007 9:06 pm

imjustpk wrote:LGM
"Edit: what about alcohol as a liquid fuel, a several yard long blue flame would be neat."

I've actually seen this, instead of using metal tanks and gasoline as a fuel some people use pvc for their tank and use denatured alcohol for fuel.

This may be a dumb question, but is there a list of materials that gasoline will corrode? Because I was thinking of a flamethrower and possibly using a 2 liter soda bottle, but I don't know if it would be eaten away by gasoline or not.
That guy said soda bottles are made of HDPE so i googled some things and came up with you do not want to put gasoline in an HDPE bottle.

http://www.diffusion-polymers.com/messages/833.html

It says at normal conditions it will be considerably.

I was researching flame thrower making and came across your thread and forum here and decided to join because its also a potato gun forum nd im interested in potato guns. I have only made a pneumatic one so far. And your 10 KB limit on upload avatar is pretty small i cant upload my avatar thats like 20 something.

Why not try using an actual gas can for your tank :) you might even find some nicely shaped ones. Probably wouldn't be to hard to tap with a small pipe for pressurizing with your gas of choice.
Kenny_McCormic
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Sat Mar 24, 2007 9:22 am

luke wrote:
Why not try using an actual gas can for your tank :) you might even find some nicely shaped ones. Probably wouldn't be to hard to tap with a small pipe for pressurizing with your gas of choice.
um no a gas tank is not made for any pressure they are made of soft plastic or very very >1mm thin metal. like 20 psi would probably blow one up
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zeigs spud
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Sat Mar 24, 2007 11:01 pm

lol if u buy pure alcohal as a fuel go ahead, but anything 78% and down for what i know is a horrible fuel.
DeathBlade
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Thu Mar 29, 2007 8:24 pm

I just though if anyone wants to know I'm going to have a flamethrower shoot this weekend, list something you want me to roast with the flamethrower and I'll get a video.
Please vote in my weekly poll for the project of the week!

www.deathblog.co.nr
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zeigs spud
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Fri Mar 30, 2007 10:30 pm

teddy bear, melon, barbie, cardboard cut out of somone.
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subterranean
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Fri Mar 30, 2007 10:43 pm

Deathblade you should post a link to your plans for your wiper pump flamethrower.
Last edited by subterranean on Sat Mar 31, 2007 5:08 pm, edited 1 time in total.
Killjoy
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Sat Mar 31, 2007 12:39 am

Don't know if anyones interested, but i finnally put my flamethrower up on spudfiles.
http://www.spudfiles.com/forums/viewtop ... 694&#71694
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