METHOD OF FORMING PORCELAIN ENAMELS

摘要

A method of forming porcelain enamels on a metal substrate comprising the steps of: (a) applying a first coating of a first slip for a first layer. (b) drying said first coating at a temperature below the softening point of the frit in said first slip at a temperature less than 350.degree.C; (c) applying a second coating of a second slip for a second layer; and (d) firing said first and second coatings in a single firing step after the application of all the slip coatings; said first slip containing a binder selected from the group consisting of an alkali silicate, colloidal silica, colloidal alumina, silicone resins, organic binder, and mixtures thereof. Sufficient bonding force is obtained between layers. In addition the substrate exhibits high corrosion resistance due to few pinholes and bubbles in the underlying ground coating.