Examination of the metal, corrosive products, and contaminated layers of a large number of bronze sculptures of different age and of different copper alloys under varying environmental loads shows in detail how corrosion proceeds. Three kinds of treatment are recommended for surface protection: protective lacquer; wax; monthly rinsing with water. For older sculptures which are already contaminated, cleaning methods like grinding off, polishing, and sandblasting are mentioned. See also AATA 8-1725, 10-169, 10-481, 10-921, 11-355, 12-558, and 15-1719 for related research on outdoor metal sculpture.