Abstract: A method for treating a metal surface involves contacting the metal surface with an aqueous silicate solution, contacting the silicate-coated metal surface with an aqueous organo-functional silane solution, and then contacting the silane-coated metal surface with a chrome-free pretreatment. Preferably, the bath containing the aqueous silicate solution also includes a cleaning agent for cleaning the metal surface. Alternatively, the metal surface may be cleaned in a separate step before the metal surface is contacted with the aqueous silicate solution and, optionally, the metal surface is rinsed with water after the metal surface is cleaned and before the metal surface is contacted with the aqueous silicate solution. The silicate-coated metal surface may be rinsed with water before it is contacted with an aqueous organo-functional silane solution. In addition, the silane-coated metal surface may be rinsed with water before it is contacted with a chrome-free pretreatment.

Abstract: A method and composition for indicating the presence of a chrome-free pretreatment for improving the paint adhesion and corrosion resistance of a metal surface. The presence of the pretreatment is indicated by adding a compound to the chrome-free pretreatment which causes the pretreatment to fluoresce under an ultraviolet light. The additive which causes the pretreatment to fluoresce under an ultraviolet light is an ultraviolet tracer, such as a stilbene or a coumarin derivative, and the method according to this invention includes exposing the coated metal to ultraviolet light.

Abstract: A cleaning and etching solution and method for metal surface is disclosed which is an alkaline formulation which includes a surfactant combination of a low foaming ethylene oxide - propylene oxide block copolymer surfactant and a defoaming reverse ethylene oxide - propylene oxide block copolymer. The preferred cleaner includes an alkali metal hydroxide, an alkali metal salt of gluconic acid and preferably an alkali tripolyphosphate and the surfactant combination.