Quick Question on Combustion design...

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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gwoloshyn
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Mon Dec 03, 2007 10:22 pm

Hey octane, are you sure the first one isn't NSF-PW? I'm a little worried, and disappointed because im near done contructing the basics of my propane/mapp powered cannon and I used DWV parts. I don't shoot my cannons all that much so maybe I should be ok?
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Mon Dec 03, 2007 10:30 pm

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Last edited by SpudBlaster15 on Wed Jul 14, 2021 6:05 pm, edited 1 time in total.
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octane89
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Mon Dec 03, 2007 10:51 pm

I don't think all of it is pressure rated. I can tell the two small elbows are, but I haven't seen rated 3"x2" bushing in any stores...(only 3" pressure fittings i seen in stores were tee's actually)

What store may carry ABS? Or online store at least....I never seen any at home depot or lowes so Im gonna assume a plumbing store (maybe ace) has it.

And do I join ABS just as I would any other pvc? Primer and solvent? Seems like a dumb question but I never used it before.
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Mon Dec 03, 2007 11:11 pm

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Cras nec placerat erat. Vivamus dapibus egestas nunc, at eleifend neque. Suspendisse potenti. Sed dictum lacus eu nisl pretium vehicula. Ut faucibus hendrerit nisi. Integer ultricies orci eu ultrices malesuada. Fusce id mauris risus. Suspendisse finibus ligula et nisl rutrum efficitur. Vestibulum posuere erat pellentesque ornare venenatis. Integer commodo fermentum tortor in pharetra. Proin scelerisque consectetur posuere. Vestibulum molestie augue ac nibh feugiat scelerisque. Sed aliquet a nunc in mattis.
Last edited by SpudBlaster15 on Wed Jul 14, 2021 6:04 pm, edited 1 time in total.
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MrCrowley
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Mon Dec 03, 2007 11:19 pm

SpudBlaster15 wrote:should I have made the same mistake when building a pressure rated PVC cannon, I might not have lived to post this message).
You wouldn't die, 110psi pressure rated PVC shrapnel wasn't enough to pierce me and two other people's skin at close range (1m).

You'd have to go a lot higher then that, which a MAPP/Propane combustion can't generate.

Though you could be blinded, you wont die...
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Mon Dec 03, 2007 11:31 pm

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Cras nec placerat erat. Vivamus dapibus egestas nunc, at eleifend neque. Suspendisse potenti. Sed dictum lacus eu nisl pretium vehicula. Ut faucibus hendrerit nisi. Integer ultricies orci eu ultrices malesuada. Fusce id mauris risus. Suspendisse finibus ligula et nisl rutrum efficitur. Vestibulum posuere erat pellentesque ornare venenatis. Integer commodo fermentum tortor in pharetra. Proin scelerisque consectetur posuere. Vestibulum molestie augue ac nibh feugiat scelerisque. Sed aliquet a nunc in mattis.
Last edited by SpudBlaster15 on Wed Jul 14, 2021 6:04 pm, edited 1 time in total.
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MrCrowley
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Tue Dec 04, 2007 1:32 am

SpudBlaster15 wrote: I have used PVC as confinement for black powder, and though the pipe experiences a much greater pressure spike, the shrapnel has on occasion managed to imbed itself fairly deeply into tree trunks. It certainly has the potential to cause significant damage to human tissue.
I'm sure PVC could kill someone, but unless like you said from cutting an artery, at 110psi you're not dying any time soon. Yes there are some variables you could change to make it kill you, but sch 40/80 wont at such little pressure.

The largest piece I found that had gone somewhere was a mere 2m away, the furthest piece only travelled about 15 feet. Not enough to kill you, and the piece was about the size of the tip of my finger.
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octane89
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Tue Dec 04, 2007 10:53 am

Thanks for the input Spudblaster15, I liked your advanced cannon quite a bit.
gwoloshyn-You should be fine from what everyone says. Some prefer dwv over abs and vice cersa. Just be safe and think things thru.
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