piston valve problems

fatcat · Sun Mar 18, 2007 9:11 pm

i am trying to make a piston valve but i am having trouble getting it to seal. i used a plugged piece of 1.5 inch PVC inside of a piece of 2 inch pipe. there is about a 1/16th inch gap between the wall of the pipe and the outside of the piston. how should i seal this?

singularity · Sun Mar 18, 2007 9:37 pm

DUCT TAPE if your ghetto like me( i have duct tape on my piston and it works awesome) just put a couple of layers on and mare sure you put some lithium grease on the duct tape or you could use o-rings if you felt like taking your time

fatcat · Sun Mar 18, 2007 9:39 pm

thanks. i tried o-rings but they were too big and i don't have a lathe to turn some grooves for them.

hi · Sun Mar 18, 2007 10:12 pm

I already said this in another forum, but I'll say it again. I just molded my piston out of hot glue sticks and bolted a piece of rubber from an inter tube from my bike on it. it works well and seals every time.

deusXmachina · Sun Mar 18, 2007 10:52 pm

What do you mean by "getting it to seal" ?

If air is leaking out the barrel, then it isn't sealing at the sealing face, in which case you have to work on the sealing surface of the piston.

If air is leaking when you open the pilot, causing delayed actuation and weak firing, you're losing air around the outside of the piston, in which case O-rings or just duct tape is a good idea.