Liquid Fuel

Boom! The classic potato gun harnesses the combustion of flammable vapor. Show us your combustion spud gun and discuss fuels, ratios, safety, ignition systems, tools, and more.
spudzinger
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Wed May 09, 2007 6:18 pm

Only problem with alcohol is that if you spray it it doesnt measure accurately, and heating it up takes a lot of time. I'd say just use spray stuff like axe and the like. Good luck otherwise Spud
cork9
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Wed May 09, 2007 6:30 pm

i use isobutain for my fual i get it from this science magazine its good stuf.
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pyromaniac
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Wed May 09, 2007 6:32 pm

Would pvc cement work? It does say highly flamable.
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spudzinger
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Wed May 09, 2007 6:51 pm

how would you measure or clean out the remnants of the pie cement? Besides, that stuff is nasty and would give off some really nasty crap.
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BC Pneumatics
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Thu May 10, 2007 5:02 pm

Has anyone tried MEK? Just curious.
pyrogeek
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Thu May 10, 2007 5:29 pm

MEK would dissolve the PVC.
If you are using an alchohol, I would suggest trying methanol. Heet gas line treatment stuff is anhydrous methanol, and is pretty cheap.
I don't have any scientific evidence, but I have compared it and isopropanol, and methanol burns better.

Butane is a good fuel, and it would vaporize a hell of a lot easier than alchohol or other liquids. It would even be easier than propane, and it's also pretty cheap.
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BC Pneumatics
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Thu May 10, 2007 7:03 pm

I doubt that an injection of MEK would do serious damage to the PVC oven anything but a very prolonged time frame.

It is far from the most practical fuel, but there is very possibly someone out there who has tried it 'just for kicks'.
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meatballs
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Thu May 10, 2007 9:38 pm

PVC cement is not a good idea, because it contains solvents to dissolve the PVC (which is how it glues the pipe together) so dont use it, it will soften and dissolve your chamber.

Methanol should indeed work better than isopropanol. isopropanol is a three-carbon molecule, and methanol is a one carbon molecule. that means that the methanol has a little less energy, but will evaporate faster and burn faster, and adding more methanol than you would with isopropanol will compensate for the energy difference. i'll have to try that out.
cork9
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Thu May 10, 2007 9:42 pm

If u could find a way to seperate just the fumes of the pvc cement then maybe its possible.
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jimmy101
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Sat May 12, 2007 3:24 pm

Using MEK (methyl ehtyl ketone) in a PVC gun would be really stupid. It is one of the solvents in PVC cleaner and glue.

I don't think it would be a good idea even though it would only take a couple drops of MEK to fuel a standard sized combustion gun. The MEK would be absorbed into the PVC fairly quickly, potentially forming a weak spot (at least until it evaporated back out of the PVC).

If you want to use a liquid fuel then you really should just use any of the very large number of flammable liquids that are compatable with PVC. Gasoline, ether or alchohol for example.
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Sat May 12, 2007 7:44 pm

You guys do realize there are many non-plastic cannons out there, right?
I would love to see the folks with metal chambers test some of these unconventional fuels.
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frankrede
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Sat May 12, 2007 9:07 pm

cork9 wrote:If u could find a way to seperate just the fumes of the pvc cement then maybe its possible.
Wow. How hard would that be?not hard at all/
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