Mac 92 head gasket

[steve welte]

Steve the answer if you can reuse it is YES. You take the gasket and heat it with a small propane or on the gas stove burner until it is cherry red. You then quench it under cold water. That takes out all imperfections and makes it dead soft like it was when new. You do the same with the .020 copper headgasket for the 91. Same process for copper exh gaskets.

[Steve carroll]

Steve the answer if you can reuse it is YES. You take the gasket and heat it with a small propane or on the gas stove burner until it is cherry red. You then quench it under cold water. That takes out all imperfections and makes it dead soft like it was when new. You do the same with the .020 copper headgasket for the 91. Same process for copper exh gaskets.

Thanks will give that a try.

[doug tenney]

I was wondering if anyone went the extra step to anneal the copper.  I knew that copper is extremely sensitive to work-hardening, but I didn't know that it was so easy to anneal.  I looked around online a little yesterday, and Steve W's approach seems to be the norm, with one exception: quenching.

Question: what is the desired effect of the quenching (water dunk) part of the process?

It seems to me that gradual cooling would make the annealing more complete.

[Vince Rosanelli]

Copper is annealed by quenching or air cooling. When annealing copper by water quenching, it remains somewhat softer and is more malleable. This is better when using it for gaskets, as it more easily forms to take the shape of and seal the adjoining surfaces when compressed. Copper is also annealed by air cooling, but I think it gains back some of its hardness that way and makes it slightly less favorable to form as a result. I'm sure someone can correct me or elaborate more in detail.