Our brass Coat Discs are coated with a clear cellulose lacquer to help protect it against oxidation. However, because brass is a compound of natural materials, we suggest you polish it every few months with a dry polishing cloth to keep its shine. If desired, you can also apply another coat of cellulose lacquer after polishing. Powder-coated surfaces should be cleaned with aqueous solutions made from pH-neutral (pH 5-8) detergents or cleaning products and soft, non-abrasive cloths, rags or industrial cotton batting. Always clean metal surfaces gently and without scrubbing so that the surface is not scratched. Never use cleaners containing granular substances, acetic acid or citric acid.