I tried filing the piston to make it fit in the pipe, it does but the seal still ain't flash, plus I have to manually press the piston up against the barrel every time. I think I might sleeve a bit of PVC in there, just so I can get smooth sides then make the piston in that...

I'll see what I can do tomorrw (it's dark now).

What function does the washer hold?

10m is like 30 ft

Negative
(msg to short)

The piston isn't filled at this stage.

I'll go epoxy the bolt now though

A bolt in the middle

Well, all the air escaping was my fault, but lets not go into that.

Now I've fixed that, but when I take the pressure past 20, it lets anything more out the barrel. Is this another sign of a poor seal?

I checked the face, I think the rubber might be a bit hard. What is typically used as a sealing face? I know it's neoprene, but I don't think it's what I have.

I swear to God I'm going to kill someone....

I'm going MENTAL. I can't get the barrel to seal (yes this is my first piston valve)...

I've tried a couple different pistons, as well as trying putting fabric or a disk of hot glue behind it (as in http://www.spudfiles.com/forums/files/untitled2_531 ...

Excuse my possible ignorance, but what IS a 'shock pump' not trying to thread jack ya, but I searched the forums and still didnt get a clear idea.

May have found something even better.

See image. b is 52.9mm, c is 55mm

Perfect width, and length!

http://www.hansenproducts.co.nz/product ... s/SMHT.jpg
I'd have to chop the thread off though

I may have found my piston, in a material that I could file a groove into.

Was looking through Marley (NZ pipe/fittings manufacturer) documents, and found the information below.

The ID of my pipe is just over 53mm. I figure I buy one, and cut if off at the red line on the diagram. Fill it with ...

I don't have a dremel though, and I'd rather not buy one, as I can't see myself using it often... a drill is pretty much all I have sadly.
Hmmm found this http://www.dse.co.nz/cgi-bin/dse.storefront/en/Product/T4823 might consider getting one if I can justify it.

I'm curious as to why you say ...

Thanks for all your help guys!

Now just gotta wait until Monday for the plumbing supply stores to reopen so I can get my barrel!

Will report back.

Tom.

Time for one of those 'how long is a piece of string' questions.

How tight SHOULD a piston fit?