The degradation of oil painted copper surfaces

Abstract

Degradation of oil painted copper surfaces involves chemical, physical and mechanical processes that are influenced by the prevailing environment. The oil paint/copper interface formed between the lower layers of paint and its copper support determines the stability of the system. Components within the painted copper system are identified and their interactions are discussed. Decay routes are described. Ingress of water and ions to the oil paint/copper boundary through paint film defects is shown to be essential for the electrochemical reactions at the metal surface that lead to adhesion loss. Destabilisation begins with bond failure and blistering, which provides ideal conditions for the initiation of delamination. The study reveals that further work on the structure and properties of copper carboxylates of individual and mixed linseed oil fatty acids, together with models of their reaction, would further understanding in this field.