How-To: Make a pneumatic cannon with a 2" piston valve.

Cannons powered by pneumatic pressure (compressed gas) using a valve or other release.
omgimonfrie2
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When did you already answer that? And were using up to 80 psi. We already put super gule in it though :(
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MrCrowley
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Well if you want to get hurt that is the way to go. I can't actually believe you used super glue, that is pretty darn stupid.
omgimonfrie2 wrote:Well it is possilbe that I am not using SDR 21, and I'll start looking for my own answers.

EDIT: I looked and did not find. Is super glue an okay solvent for brass piping? I just bought parts for a marshmellow sniper.
I meant I gave you the answer to the SDR-21 gholfball question.
omgimonfrie2
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Well I just checked and I was wrong: I have SRD-40

I had no clue that super glue will not work. What would you say the max psi should be?
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MrCrowley
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0PSI.

Learn how to build a spudgun before you actually build one.
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SpudUke5
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LOL........... :D
But dont be all frustrated we were all at one point stupid enough where we thought super glue could work.
omgimonfrie2
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Well I just had it at 130 and it dosen't leak or anything. What SHOULD I use? And my apolgies for drwaing this topic so off track from 2" piston valves.
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MrCrowley
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PVC welding solvent(aka PVC cement) and PVC primer.

I don't see how super glue holds together copper at 130psi unless it's an epoxy.
omgimonfrie2
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I leaks like crazy and I'm considering building a wooden box to put it in, then pumping it until it blows. I'lll have to do this for every joint, and then I'll use the pvc cement.
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MrCrowley
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What are you using as your building material? Copper, PVC, ABS?
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ShowNoMercy
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Why not put it all in a garbage can, save yourself the trip to the hospital and start over? Do it right and you will enjoy it a lot more, especially since you wont be doubting the structural integrity of your cannon.
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omgimonfrie2
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Copper. I'm having a hard time even thinking of throwing it out. I already paid for it.
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octane89
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edit- You can scrap copper, just take it to a scrap yard and see how much you can get back. Or you can try to take everything apart from the glue.

I would just forget the project, or never go over 1psi. I'm using pressure rated piece, pvc cement, your basic supplies and Im still hesitant to launch sometimes. But super glue is a bad idea, and think you may of rushed a bit.
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MrCrowley
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Octane are you using primer as well?

omgimonfrie2... Either try and pull it apart or scrap it, I don't see how you can even think that superglue would hold copper together at even low pressures.

If you get it apart, you need to clean all the joints and buy some copper bond epoxy from HD or solder it together.
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octane89
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Yea-I don't want to run at 100psi and not be 110% Im doing anything right. The primer is much needed.
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ShowNoMercy
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If its copper and super glue, can you try using a butane torch to heat it up and pull it apart? Just do it outside and or use a gas mask.
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