Best kind of rubber??

[spudthug]

hey guys. i was jsut wondering what the best kind of rubber was (dont be perverted...). Like material and hardness..because my sealing faces usually leak a little bit. i was going to order some off of mcmaster but first i need to know the best kind..

[MrCrowley]

Orange gasket rubber I find at hardware sotres unding the plumbing section like taps and toilets etc is usually pretty solid. It seals fine and is more then 1/8" thick.

[DYI]

Butyl rubber would be very good but it's kind of expensive ($10.49 for a 12" x 12" 1/4" thick sheet). It probably would be the best choice though. I've never used it as a sealing face on piston, but I have made gaskets to seal a union with it, and it performed very well.

[spudthug]

ok next time i go to ace ill look.. do you think they have it there?

edit: why would i order butyl rubber? all it is is an intertube...

[paaiyan]

Gasket rubber, like Crowley said, or if you can find some sort of silicone gasket that fits, get it. Silicone seals very well.

[Modderxtrordanare]

Is it hard to just experiment and play around with things on your own?

Be creative, think a little.

[dongfang]

Hi

if you use o-rings as seals and the common ones are too soft, the secret formula is called: NBR 90 Shore. These o-rings are made of a harder compound (for up to 90 degrees Celsius, I have been told).
The common o-rings are called NBR 70 Shore. A softer compound. Silicone rings are even softer.

PS: In my only piston valve design so far, the sealing surface is on the valve seat (embedded o-ring) and not on the piston. After initial assembly, it did not work ... a leak of, say, 0.3 mm somewhere on the circumference. I solved it by gluing find sandpaper on the head of my spare piston and putting a shaft on it - great honing tool. It fits down the valve body tee the same as the real piston, and I got the seal surface ground to be at an exact right angle to the piston axis, even when the valve seat was not.

Is it hard to just experiment and play around with things on your own?

Be creative, think a little.

OK, but aren't seal problems the only really boring and frustrating time-wasters in pneumatic spudding? They are for me.

Regards
Soren