I am installing 22ga. galvanized steel plate on the walls behind my woodstove. I could not acquire ceramic spacers locally, so I purchased copper plumbing fittings about 1" long to use as spacers. I know that, in a wet setting (on a roof, for example) copper and galvanized steel should never meet. The copper and steel will react in the presence of h2o and corrode. Should I be concerned about using copper spacers which come in contact with my galvanized steel plates?