I have some basic questions about coin dipping. Just stuff I never learned. 1. I have heard in certain places, mostly coin forums, that dipping copper coins is unacceptable and will ruin the coin. Is this true to any extent? Or maybe only for RB copper? 2. Several times I have overheard my LCS dealer state that "cross-dipping" coins of different metals will mess them up. i.e. Dipping platinum coins in silver dip and vice versa. Is this true? Any answers/responses are appreciated, thanks.