First, dont laugh... I made gaskets from an old tractor tire tube. They are about 1/16" thick rubber and have worked fine so far. I would like to improve my materials a bit in the future so I am looking for a better gasket material/supplier. My plates are roughly 8"x8" SS. When I started this project I did look for gaskets at auto shops, but I did not have any luck finding the size/shape needed. So, how/where are you finding gasket to fit this size plates? When I looked at the auto shops I found a lot of round gaskets but none that were close to 8x8 square. Any ideas?