SpudFiles

I made a Air Cannon with 3" PVC and adapted it down to 1.5 I used a clean out cap on the end and put a Tire Valve in it.. The valve works fine but the clean out cap leaks around the threads ....

How or what do I use to stop the leak????

First of all, get rid of the cleanout cap and buy something pressure rated. Why would you even need a cleanout on a pneumatic?

yeah, just cut your pvc at the begining of the female part of the clean out cap fitting, and the glue an end cap with your schrader vavle in it. My only other suggestion would be to use a lot of teflon tape and screw it in as tight as possible

You could wrap the hell out of it with PTFE tape and crank it down good.

ok, yeah, if he needs to hear it twice

I had the same problem with the cleanout cap on my piston cannon. Teflon just wouldn't do the job, so i switched to liquid pipe joint compound. The stuff i use is made by Oatey and is called Great White pipe joint compound. It works great, just follow the instructions and then screw the cap on with a large wrench until you can't anymore.
If you want it to be absolutly safe, switch to a pvc plug, or glue an end cap onto a male-thread adapter (both pressure rated) and screw that into where the cleanout cap used to be. And mount your valve in that.

Get rid of the whole clean out cap and go with a pressure rated end cap.

sorry killjoy, i thought PTFE was similar to teflon tape.

wait im confused, why are you apologizing to me? I think it was pyrogeek you corrected.
And im pretty sure teflon and PTFE tape are the exact same thing, they just have different names.

Killjoy wrote:wait im confused, why are you apologizing to me? I think it was pyrogeek you corrected.
And im pretty sure teflon and PTFE tape are the exact same thing, they just have different names.

They are.

Ok there is two options to prevent the leaking occurring on the mentioned joint. One was to add teflon/ plumbers tape to the threaded connection, as it is commonly applied to threaded connections as to prevent the leaking of the threaded connection. The other being to cut the pipe off at the end of the fitting. Then proceed to glue a slip cap onto this newly cut section. Glue was proposed to seal the threaded connection, although I would advise against it as the connection is already weak, and that the glue would have a hard time dressing all the small facets found on a threaded connection. In conclusion I would suggest that you glue the slip cap on instead of utilizing the current threaded connection.