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how can I get a good seal on a pvc air gun? Answered

so I have been making pvc air guns and i have encountered a problem with my newest air gun. the seal between the pvc end cap and bike valve(witch is cut from bike inner tube and then hot glued in) is not the best seal. is there a way to get a guaranteed seal, with out breaking the bank. also best answer will receive one million..........pretzels. thanks for reading, and please post your advice.


You could use aqua defense.Its a paint kind of rubber you can get it at LOWES or home depot.All you do is simply paint on the the liquid like substance and then wait for it to dry.When it's dry it will be a nice kinda thick rubber coat. :)

Tech Dawg,


6 years ago

Cheap and easy plastic epoxy such as

Will weld your PVC just fine. Nevermind the bad reviews. Those users were looking for too much and/or probably didn't prep surface properly.

Industrial-grade answer: go with West Systems http://www.westsystem.com/ss/gluing-plastic-with-g-flex-epoxy/

Now I have a question for you: ever made a bank of large-diameter PVC tubes to act as a compressor reservoir (to supplement something smaller like a pancake compressor)?

The first problem is your glue. use a much stronger glue like epoxy, or my favorite, locktite (jb) weld. second, it should be glued on both the inside and outside, with plenty of leftover rubber from the tire left on the inside to give the glue more surface area to bond. this should provide an excelent seal, but if it's still not working for you, try using an auto tire valve from your local auto parts store.

Try the zoo. Ask around and make sure he came from a good stable home.

A 1/8" NPT to schrader (tire) valve fitting is not too expensive. They may not be available at every hardware store, but they are out there. I've found them for $3 or less.

You'll need to drill and tap the end cap for the NPT thread side of the fitting, and thread the fitting in place using pipe tape ("teflon tape") to ensure a good air tight seal.

I don't know if this would be breaking the bank. Its more expensive than a valve salvaged from a tire, but overall its still less than $10.

Weld a few more layers of PVC on the end, bore through them, and reglue, with a lot more bond area.