Bradley Restoration

Also called Loctite 518, among other things.  This is a red anaerobic gel, similar to Loctite, capable of forming a gasket between two flanges up to .030” thick.  Apply the stuff, bolt the parts together and wipe off the excess.  The product that remains between the parts will thicken to flexible solid.  Weird, but useful.  I know of several shops that have completely given up using paper gaskets in favor of this stuff. Not cheap, but a little goes a long way.