need help with coaxial!!

[hawktalk]

i cant get the piston to seal when i charge the gun up. I have to put a bit of rubber of the end on the barrel and wait till it reaches 100psi the it will kinda seal. any suggestions.
I put a rubber sealing face on the piston its almost tight in the barrel. how much travel should the piston have?
would making the piston heavier or lighter make a difference?

[jrrdw]

Sounds like the end of the barrel isn't smooth or straight enough. Try wetting it, some times that helps. If you need to re-surface your sealing face you can cut a piece of 600 grit sand paper and put it on your piston face and spin your piston to get the proper angle to re-surface the barrel end.

[hawktalk]

I've got it working now kind of. the rubber i bought is very smooth and its shinny after rubbing it with some sand paper it seals i have to help it to start but it does seal. now its working I'm going to superglue most of the compression joints because I'm loosing pressure very slowly through them somewhere. thanks for the reply.

[jrrdw]

Superglue??? Don't you solvent weld?

[hawktalk]

thanks for the reply Why not? for leaks in compression joints its works great and with a sharp opening force it will break easily and crumbles off. all my joints I've used Teflon tape and works great but for one bodged joint i think there is a slight gap between epoxy and thread supper glue will get in there because of its low viscosity. picture below

[jrrdw]

When you said "compression joints" I was thinking you was using slip joint adapters. If you would have said the blow gun was leaking I would have known right where you was talking about, that's a common leak no matter what it's hooked up to.

[hawktalk]

how would you fix it?

[jrrdw]

how would you fix it?

Teflon tape.