Everything Old Is New Again: Revisiting a Historical Symposium on Zinc Oxide Paint Films

Abstract

On June 6, 1949, members of the Victorian Branch of the Oil and Colour Chemists’ Association gathered in Melbourne, Australia, to share their concerns regarding a sudden increase in problems associated with zinc oxide oil paints, problems which Association members posited were tied to industry-wide changes in processing methods for the zinc oxide pigment. The issues raised during this meeting inform and parallel current studies regarding metal soap behavior. This paper reviews the topics discussed at the 1949 symposium, distilling the historical research and its relationship to modern conservation and scientific inquiry. Topics include existing research literature, pigment processing methods and observed relationships between particle morphology and paint film behavior, and zinc oxide paint film failure patterns. Related metal soap research from the period is also discussed, including investigations of zinc oxide soap formation, the effect of environment on soap formation and film failure in zinc oxide oil paints, and the impact of zinc oxide-specific failure mechanisms on single- and composite-paint systems.