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Piston valve cuts sealing face
Posted: Thu Apr 19, 2012 11:35 pm
by Marffy
My Gun cuts the seals up and spits them out. The piston is domed and has a screw and washer holding a 1/8" thick round piece of gasket material. It seals up against the barrel; a 1/2" copper pipe (type L? idk the thicker stuff). Whenever i air it up i can get a 1 shot then i fill it up again and the barrel just cuts the seal/gasket like a cookie cutter. Is there a way to stop it? Should i get a thicker gasket and barrel or something? what about a different stronger kind of sealing material?
Posted: Fri Apr 20, 2012 12:06 am
by pneumaticcannons
thicken up the barrel where it meets the sealing face. On my latest marker gun I used some tape wrapped around the barrel as a mold around the barrel so I could cast some epoxy in order to make that area of the barrel thicker. Don't worry if this sounds complicated, jsr will probably pitch in and give you 10 more ways to to this if he hasn't already

Posted: Fri Apr 20, 2012 12:08 am
by jackssmirkingrevenge
you could try flaring the end of the copper to give it a larger surface area and softer edge for the seal to push against.

Posted: Fri Apr 20, 2012 12:48 am
by Crna Legija
I also use a bit of copper for the seat it happens to me a lot as well so i cut a short bit of tube expanded it with pipe expanders then soldered that over the seat to double the wall thickness.
Posted: Fri Apr 20, 2012 1:09 am
by jackssmirkingrevenge
pneumaticcannons wrote:jsr will probably pitch in and give you 10 more ways to to this if he hasn't already

if you insist
have a look here:
http://www.spudfiles.com/forums/smalles ... t9893.html
You can have the sealing face on the barrel itself, allowing you to use a simple "solid" piston:

Posted: Fri Apr 20, 2012 12:04 pm
by mattyzip77
a new barrel, thicken existing barrel at sealing point, a thicker sealing face, all of these will work. I would try a better sealing face. Good luck!!
Posted: Sat Apr 21, 2012 12:46 am
by Marffy
I'm gonna keep messing with the gasket material too because it keeps blowing out. Thanks for the ideas i like the flairing idea but it looks complicated. I might try to use epoxy on the barrel or something
Posted: Sat Apr 21, 2012 12:48 am
by jackssmirkingrevenge
Marffy wrote:i like the flairing idea but it looks complicated.
All you need is a hard sphere bigger than your barrel diameter (a marble would be good in this case) and a plastic mallet.
Posted: Sat Apr 21, 2012 12:55 am
by Marffy
Oh. That seams easy enough. I forgot how malleable copper is