Abstract: A protective coating composition with early water resistance is prepared, according to principles of this invention, by combining in the presence of water and in their proper proportions: (1) zinc dust; (2) a Group IA metal silicate; (3) a colloidal silica ingredient that is modified with a Group IA metal silicate; and (4) a carbonate-containing internal hardener. Optional ingredients such as a stabilizing agent, external hardener, pigments and fillers, and other additives can be used to achieve certain coating properties depending on the final intended coating application. The Group IA metal silicate and colloidal silica ingredient that is modified with a Group IA metal silicate react, in the presence of the other ingredients, to form a silicate network having early water resistance, i.e., water insolubility, improved high-temperature resistance, improved corrosion resistance, and zero volatile organic content.

Abstract: A corrosion-inhibiting coating composition for application onto rusted steel or iron surfaces is disclosed. The coating composition comprises an organic silicate, citric acid, and a non-aqueous solvent. The organic silicate is preferably present in an amount sufficient to provide about 12% to 24% silicon dioxide in the cured coating from the composition and is preferably pre-hydrolyzed in an amount of about 70% to 90%. Citric acid is preferably present in an amount of about 0.1 to 0.2 grams per cubic centimeter of the coating composition. Dissolution and complexation of the rust by the citric acid provides a pigment which causes the organic silicate to become a film-forming binder. Zinc chloride is preferably added to the composition to increase the rate of rust dissolution and to improve binder properties.