The author describes the increasing threat to outdoor bronze sculpture. The contrast between the effects of corrosion on surfaces of archeological and modern bronzes is discussed. A history of attitudes toward surfaces and research into problems of preservation are sketched. Examples of treatments and the necessity of rewaxing treated bronzes four times a year are cited. Methods at the Center for Archaeometry (Washington University, St. Louis, Missouri) for cleaning, patination, and surface coatings including Incralac and waxes are described. See also AATA 14-584.