Re-Using a Copper Head Gasket
Copper head gaskets can be re-used, but before you fit it you need to soften (anneal) it. Copper hardens with work. To soften it you heat it up. Most metals must be worked when they are hot, but copper is worked when cold. This is a job that is easily undertaken by an amateur at home with a gas blow torch.

To anneal (soften) copper, heat to a dull (cherry) red & let it cool. It does not matter whether it cools in the air or is quenched in water or oil, it comes out the same. Quenching in water will remove most of the black oxide coating and it will come out clean and bright or you can clean it up with steel wool.

A gasket is typically thin and so just letting it cool in the air will allow you to be able to work with it in about 10 minutes. 

  • Don't use Oxy acetylene....way too hot. 
  • Don't ever bead blast. 
  • Heat from the bottom up. It makes it easier to see the colour (dull red) in a darkened environment. 
  • You don't have to get the copper heated all at once. You can do a corner today , a corner tomorrow. 
  • The trick is to get the entire gasket to that colour at one time or another.
  • The acid in brown sauce (Ketchup) will clean off the oxide.