Abstract: Disclosed herein is an alkali silicate based protective coating for metal surfaces. The coating is substantially defect free, and provides for an impedance of as high as one million ohms or more at a frequency of about 10 Hz.

Abstract: A process for forming a protective layer on a rigid surface, such as a metal or wood surface, to provide protection against abrasion, corrosion, heat and fire. The process comprises first preparing the surface of the article. On metal articles, the surface can be prepared by cleaning the surface and then exposing the surface to concentrated phosphoric acid. On wood, the surface can be prepared by thoroughly cleaning the surface with hot water and detergent only. Preferably, the surface is prepared such that a uniform, continuous layer of liquid can be formed thereon. After the surface is prepared, a 10-16% (v/v) silicate-containing solution is then applied for 20 seconds and allowed to dry completely at 305.degree. F. to form a layer of silicate material over the surface. During the drying process, at least a portion of the sodium silicate is converted into silicon dioxide. An acid is then applied to the surface to form the protective layer on the surface.