Abstract: A concrete or metal substrate which is normally subject to deterioration in the presence of corrosive substances such as strong acids, particularly sulfuric acid, is rendered corrosion resistant when covered with the improved multilayered coating of this invention. In particular, a coated article, such as a coated chimney liner or flue duct, which includes a substrate, a primer coating layer of a thermosetting polymer, one or more inner coating layers of a thermosetting polymer which includes a siliceous filler, an intermediate coating layer of a thermosetting polymer which includes a non-siliceous filler, and a fluoroelastomeric top coating layer which includes a non-siliceous filler, has improved resistance to the corrosive effects of strong acids. Chimney liners, flue ducts, scrubbers, and the like which have been coated in accordance with this invention are useful in power plants, smelters, and other industrial settings where corrosive environments are present.

Abstract: Multi-layered coating compositions which comprise one or more inner coating layers which are admixtures of polymers formed from thermosetting polymeric materials and reinforcing filler materials and an outer coating layer which is an admixture of a fluoroelastomeric material and a reinforcing filler material are useful in preventing the corrosion and/or deterioration of surfaces which are in contact with corrosive substances such as strong acids, particularly, sulfuric acid. Such coating compositions are especially useful for preventing corrosion of the surfaces of the chimney liners, flue ducts and scrubbers which are present in many power plants and smelters.