Annealing Copper Gaskets

Annealing Copper Head Gaskets and Sealing Washers:

Purchasing a new head gasket is not always necessary. In many cases the old head gasket can be reused by annealing. There is a limit to this 2 or 3 uses is about all you will get. Most of our gaskets are supplied pre-annealed.

What is annealing?

Annealing is a metallurgical process of heating metal and cooling it to soften its atomic structure. In this case we are focusing on copper. Soft copper washers and gaskets seal much better than one that is untreated.

In the case of copper we can visually see a color change in the material:

Left is a annealed. Note the color changes

Right is untreated

Here is a simple method for annealing a head gasket:

Just put the copper gasket or washer on an electric or gas stove burner, turn it up to high, and when the gasket turns red, turn the burner off and have a cup of coffee. Quenching of copper is not required.
Clean surface gently with Scotchbrite pad and install.

We don’t recommend using map or acetylene gas torches. These tend to overheat and scorch the copper.