Effectiveness of corrosion inhibitor films for the conservation of bronzes and gilded bronzes

Corrosion inhibitors, associated or not with protective coatings, may be a good solution for planned conservation activities in the case of bronze and gilded bronze artworks. In this work, alternatives to BTA for the inhibition of bronzes and gilded bronze are investigated. The experimentation includes a screening of many organic substances as film-forming corrosion inhibitors for a copper alloy reproducing the composition and the microstructure of a Renaissance leaded bronze. The results, obtained after exposure to 3.5 wt.% NaCl solution or concentrated artificial rain, show that, if proper curing conditions are adopted, excellent protective properties are offered by 3-mercaptopropyltrimetoxysilane.