Composition of Enamel & Enameled Wares

Enameled ware is sheet iron or steel coated with a glazed material which protects the iron from rusting. This coating is not actually united with the iron as in the case of tinned ware, but is fused or " fired " on so that it will withstand ordinary usage. The foundations are made by the methods described in the preceding chapter. The foundations must be firm and unbending or the enamel will chip off when the article is bent and expose the iron to action of rust. In time this action will undermine the entire covering.

Composition of Enamel

The hard, smooth coating of enamel is a form of glass, and like glass is composed chiefly of silica, or sand, combined with feldspar, potash, soda, borax, and some substance to produce the required color. The proportions vary in different manufactories and are carefully guarded trade secrets.

There is, however, one very striking difference between the ingredients of glass and those of enamel. Glass often contains substances, like arsenic, which are perfectly harmless so long as the article is not subjected to heat, but which would be poisonous in cooking utensils. Such materials are not used at all in enameled ware.