John,

I'd exhaust all of your other options first. Then, if I struck out, I'd
try molding my own part:

a) I'd get a piece of hardwood...something with a nice tight grain.

b) I'd take a router, and route the pattern I wanted into the wood. This
is the mold.

c) I'd oil the wood...mineral oil, maybe? This should act as a mold release.

d) I'd get a cartridge of silicone RTV, put it in my caulking gun, and
lay down a nice heavy bead in the mold.

In your case, you might consider using one of the automotive
RTVs...black or red types...those are used in more chemically hostile
environments so they may have stabilizing compounds that might work to
your benefit in the chlorine-rich environment of the pool pump.

You can get RTV rubber in sheets, IIRC. Another possibility would be to
lay out a pattern on the sheet, and then carefully cut it out with
scissors and/or a sharp knife.

I don't know if any of this would work, but hey...It might be worth trying.

Pete
www.hpfriedrichs.com




John Keiser wrote:
I know this is off-topic but you folks are very clever and may have a
solution.

My swimming pool sand filter is 30 years old. Parts no longer available.
The valve has begun to leak from a "spider" gasket - basically an 8 inch "O"
ring and a "1 inch "O" ring connected by 3 radials [which separate
rinse/filter/backwash chambers]. The gasket must allow the valve body to
rotate to the three positions so I doubt anything as simple as silicone
caulk would work.
No comparable part available AFAIK.
Replacing the sand filter would not only be pricey, but labor intensive.
Does any one have experience making [or piecing together] such a gasket? Or
a link that might help?
Thanks for any wisdom.