Annealing Copper dead soft

Heat it until smoking hot (not a terribly precise measure) and plunge into water. It will stay fully annealed for a couple of days.

Jon

The plunging in water part is not needed. Heating to red hot is however. And it will stay annealed until it is work hardened again.

Lane

Those are the exact instructions from a '56 Triumph motorcycle manual in reference to their copper head gaskets. Heat to red hot and air cool to anneal them. I did it that way and didn't have any gasket leaks with higher than stock compression pistons.

Garrett Fulton

Yeah, but plunging into water makes it shed all those dirty oxides & it comes out bright & clean--if it's a straight-8 gasket, it's perty difficult to heat & quench all at once!

Thanks for the info. It's for a '64 Honda S90 that I'll be restoring. First step is to get it running and take it to DMV to get the salvage title process going.