Patent ID: 7264740

Claim:
A metal surface treatment to increase strength, flexibility and fatigue life of a metal, and to protect metal-to-metal bonds at the apexes of cracks, scratches and gouges on the surface of the metal, comprising the steps in the following order of: (a) cleaning the surface of the metal to remove mill scale, soils, oils, corrosion products and previous coatings; (b) removing moisture from said apexes; (c) applying a metal etch to the surface of the metal; (d) rinsing and drying said metal surface; and (e) applying a liquid corrosion preventative compound to said etched surface, whereby the strength, flexibility, and fatigue life of the metal are increased relative to a metal surface that has not been treated with steps (a) through (e), wherein said liqiuid corrosion preventative compound has a surface tension of less than 30 dynes/cm and has a composition that comprises either (i) 80-98 weight percent 1,1-dichloro-1-fluoroethane, 1-5 weight percent oxygenated hydrocarbon, and 1-5 weight percent carbon dioxide propellant, or (ii) less than 10 weight percent barium dinonylnaphthalenesulfonate, a homopolymer of 1-decene, 2-butoxy-1-ethanol, and ethyl acetate.