Propane fueled, 2" barrel.

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.
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Tater Salad
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Thu Jan 25, 2007 4:39 pm

This is my 4th gun and i wanted to go big so my friend and i put together $60 to make this.
It has
interchangable barrels,
rear- loading
8ft 2" barrel, 7ft 2.5" barrel, and 10ft golfball barrel
chamber 4"x4'
chamber fan
injected (not metered) propane
stun gun ignition with spark strip.

Image

I'm getting rid of the blue tape and painting it soon, but since this picture was taken there have been some other minor improvements.
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medievalman
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Thu Jan 25, 2007 4:47 pm

The gun looks like it would be pretty powerful. and im sure it will look nice when you paint it!
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Tater Salad
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Thu Jan 25, 2007 4:56 pm

Actually I can get damage pics easily, I have a painted target which is 26 gauge sheet metal screwed onto 3/4 inch plywood, most rocks and things I shot from 20 yards go right through. I'll get those up ASAP.
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Pete Zaria
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Thu Jan 25, 2007 5:31 pm

May I ask how reliable it is without a meter system? Do you open the torch valve just a crack and count for xx seconds or something? How do you get a reasonably consistent fuel/air mixture, given tank pressure fluctuation and temperature and things...?

Just wondering.

Nice design. Huge chamber. It will look great with a paint job and hose clamps / zip ties instead of blue tape :wink: Can't wait to see it. Great job considering the $60 budget. Most of my guns end up over $100, and some aren't as nice as this.

Peace,
Pete Zaria.
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Tater Salad
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Fri Jan 26, 2007 8:19 pm

actually a few tests and we determined that about 45 seconds is best at full blast. take off 5-10 seconds for extra warm temps and add 5-10 for colder.
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Insomniac
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Fri Jan 26, 2007 8:25 pm

Are those DWV parts???
I wonder how much deeper the ocean would be without sponges.
Right now I'm having amnesia and deja vu at the same time. I think I've forgotten this before.

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Tater Salad
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Fri Jan 26, 2007 8:41 pm

yes, they are DWV which accounts for the low cost and me not caring whether or not i die.

edit: I might mention that I am forced to wear ear protection while shooting this, the recoil is powerful and its extremely loud.
Last edited by Tater Salad on Fri Jan 26, 2007 8:44 pm, edited 1 time in total.
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medievalman
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Fri Jan 26, 2007 8:44 pm

well, dwv should be fine on a combustion, but anything more powerful is pretty dangerous!
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frankrede
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Fri Jan 26, 2007 8:46 pm

Insomniac wrote:Are those DWV parts???
And there is nothing wrong with that. Unless its thinwall. How long do you leave the fan to vent? I imagine it would take ages.
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Tater Salad
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Fri Jan 26, 2007 8:49 pm

the fan vents for however long it takes to load the next potato, around a minute, and i use it to mix the fuel too for about 10 seconds once it's finished injecting.
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