I bit the bullet and purchased a CCOT tub. The sheet metal was zinc plated prior to assembly and is really very smooth. I have mated the sandblasted cowl and now would like to use a DTM epoxy primer but I am unsure on how to prep the zinc plated tub. I hate to media blast or even sand to much for fear of removing the zinc coating but I know a good coating of epoxy primer offers good protection. If I went with an etch primer could I just use a good wax and grease remover without breaking up the surface?