Abstract: Paintable compositions for the formation of coatings on, for example, iron-based metals that, when dry, inhibit oxidation, decarburization and other similar reactions when the metal is heated to temperatures of about 2300 degrees F. (1300 degrees C.). The preferred binder portion of the composition, which in itself provides reasonable protection when dry, consists essentially of an aqueous colloidal silica solution together with an aqueous alkali hydroxide and oxides selected from the transition metals cobalt, chromium, iron, manganese, nickel, titanium, zinc and zirconium. The composition is benefitted by the addition of Sb.sub.2 O.sub.3. The preferred ranges of composition are described as well as certain additives to enhance performance under various conditions. These include the use of filler materials, as well as high expansion additives when the coating is to withstand temperatures recycling of the metal, and low expansion additives to enhance spallation following a single heating.