Copper gaskets can be reused if they are heat treated before reuse. New gaskets are relatively soft and pliable. When torqued and exposed to heat from the engine running, they harden and are no longer able to conform to the spark plug seat if removed like when they were new and pliable. If you take these used, hardened gasket and heat them ( I use a piece of safety wire strung through several gaskets) with a torch, you can restore its original properties. Heat them with a plumbers torch until they glow cherry red, and then douse them in a bucket of cold water. They will come out as soft as they were in the beginning. Just to be sure, take one of these re-heat treated gaskets in your hand and try to bend it. You'll find out it's quite easy. These used gaskets are ready for use. Try a little scotch brite action on them if you want them to be shiney again (for whatever reason).
Scott,
I was going to call you out on this but did my research first. I have always Annealed copper with a slow cool not a quenching with cool water. I believed that cooling slowly was the only way. I found this.
Annealing, in metallurgy and materials science, is a heat treatment that alters the physical and sometimes chemical properties of a material to increase its ductility and to make it more workable. It involves heating a material to above its critical temperature, maintaining a suitable temperature, and then cooling. Annealing can induce ductility, soften material, relieve internal stresses, refine the structure by making it homogeneous, and improve cold working properties.
In the cases of copper, steel, silver, and brass, this process is performed by heating the material (generally until glowing) for a while and then slowly letting it cool to room temperature in still air. Copper, silver[1] and brass can be cooled slowly in air, or quickly by quenching in water, unlike ferrous metals, such as steel, which must be cooled slowly to anneal. In this fashion, the metal is softened and prepared for further work—such as shaping, stamping, or forming.
http://en.wikipedia.org/wiki/Annealing_(metallurgy)
Learned something new today. Copper can be cooled fast or slow.
Sorry to doubt you Scott.