Improved process for cleaning metals

A process of removing rust from ferriferous articles comprises treating the articles with an aqueous solution in which the rust-removing ingredients consist of at least 7% by weight of an alkali metal hydroxide and at least 3% by weight of an organic additive. The organic additive is one of the group consisting of trialkanolamines, inositols, polyhydroxy alcohols derived from tetroses, pentoses, hexoses and heptoses, and mono- and dicarboxylic acids derived from tetroses, pentoses, hexoses and heptoses and water soluble salts thereof; examples of such compounds are saccharic, gluconic, mucic, and tartaric acids or their sodium or potassium salts, mannitol, sorbital, or erythritol and their structural isomers. The solution may also contain alkali metal silicates and phosphates and surface active reagents and it is stated that such solutions will remove rust, oil, grease, and paint at the same time. It is preferred to use the solution as a dip or a spray at a temperature approaching the boiling point.