THE EFFECTIVENESS OF WAX IN PROTECTION OF BRONZES COVERED WITH ARTIFICIAL PATINA IN OUTDOOR EXPOSURE

Abstract

Lately there is a major concern about the preservation of artificial patina applied on art objects made of bronze. These studies are important in the restoration and conservation of bronze monuments exposed outdoors. In this context, the present work aims to study the efficiency of wax-based films (WF) on the protection of two artificial patina (brown and golden) in a solution containing Na₂SO₄ and NaHCO₃ (pH 5) simulating acid rain. The protective effect of the artificial patina with/without wax-based films was investigated by electrochemical and non-electrochemical methods. The chemical composition of the golden artificial patina/ Carnauba wax layer was determined by X - ray fluorescence analysis, and the morphology was determined by SEM - EDX cartographies. The results have shown that both artificial patinas exerted an anticorrosion protective effect on bronze and the wax improved even more the corrosion resistance. The protection conferred by the golden artificial patina was significantly improved by using Carnauba wax (Cw) and a corrosion inhibitor (2 - mercapto - 5 acetylamino - 1, 3, 4 - thiadiazole).