Q. I work for a jewelry company and am in charge of adding decorative effects to the jewelry. During this decorating step, we put color coatings on silver- and gold-plated items. I need a clear topcoat to give these coated decorations more durability. We use the colored paints for a base coat, but what would you recommend for a topcoat? It seems all the ones that I have looked at have arsenic in the hardener, so we can’t use them on children’s jewelry. Naturally, we would like to be able to brush on the protective clear coating. P.H.
A. When I was a scientist at Westinghouse Research Labs, we developed a coating for the inside of small aluminum beer kegs to be used in residential refrigerators. As you know, any coating that comes in contact with food has to be approved by the Food and Drug Administration. We had to list all the components of the formulation to get that approval.
I suggest you contact the FDA for a listing of its approved coatings, and choose an epoxy, polyester or polyurethane coating from that list that meets your performance requirements.