SpudFiles

I am going to be making a basic ball valve pneumatic cannon, and was wondering how i get the schrader valve to stay in the back of the compression chamber without it leaking? I was thinking epoxy right?

after u get the right size taped hole just wrap the valve in teflon tape or appoxy it

I'm brand new here, so I don't know the application. With that caveat in mind, can you not use an automotive valve for a tubeless tire? Just drill a hole the same size as in the rim and pull the valve through from the inside until it seats on the groove in the rubber base.

Now, to peruse the forums for my own questions!

KK

you can do that, though most people dont like those kinds of valves because they need such big holes, look around the compressor section of a hardware store for a tank valve, it has 1/8" NPT threads on one side of it (meant to screw into a port on an air tank) you'll also need a 1/8" NPT pipe tap,
if you dont know what a tap is, its a tool that you screw into a hole and it creates threads inside of the hole, in this case its the same threads as your tank valve will need, dont screw the tap all the way through, just put it in enough that you can see it on the inside of the pipe you're tapping.
once you've tapped the hole put some teflon tape around the tank valve's threads and screw it in, most likely you'll need a 7/16" wrench to screw it in enough so it doesnt leak.

make sure you drill and tap your hole where there are 2 layers of PVC plastic, where a fitting is glued over the pipe would be 2 layers. also use only fittings labeled NSF-PW DO NOT use fittings labeled NSF-DWV those fittings are not for pressure, and will not be safe. also for your pipe make sure your pipe has a pressure rating on it such as XXX-PSI avoid cellular core pipe as it will burst and is not safe at all.

you may want to go with a threaded 1" ball valve, that way you can switch to a sprinkler valve, or a modded sprinkler valve since the ball valve is about the worst valve for performance

i have a tubless valve thing and it works fine. has never leaked and didn't even need that big a hole, i just pushed it through.
---Julz

yea those pull in valves are great no waiting for the glue to dry or anything!!!

but dont they take 3/4" holes because i used to use them and thats the size hole i needed, but i did here of one person so had one and forced it through a 1/2" hole, but still a schrader valve only needs a 1/8" hole and u dont need to glue it in i just put teflon tape around mine.

you dont need a 1/8" hole, you need a 5/16" hole and then you tap it then you screw the schrader valve in

dunno how much schrad... valves are but my tubeless one was only one dollar
---Julz

the screw in valves are good. get the 1/4 NPT type and then just drill a 1/2 hole and it will fit in beatifully
EDIT:srry my bad ...i didnt even look at the ancientness of this post

Um this is an ancient thread... don't bring it up...

Anyways just buy a 1/8" NPT Schrader valve and drill an 11/32" hole and thread it in.