Corrosion and conservation of cultural heritage metallic artefacts: 24. Sol-gel coatings for the preservation of metallic heritage artefacts (European Federation of Corrosion (EFC) Series)

This chapter gives general information on the production of sol-gel coatings with alkoxysilanes. Some examples of their application on outdoor bronze artefacts are reported. The protective effects of 3-mercapto-trimethoxysilyl-propane (Prop-SH) hydroalcoholic solution on polished and patinated bronzes were studied. Electrochemical tests, performed in acidic artificial rain (AAR, pH 3.1) and in 5% NaCl solution for 168h, were checked in 45d AAR Salt Cabinet and in 30d ASTM B117 Test on bronze statues. The treatment with Prop-SH showed high efficiency towards the corrosion both in AAR and in 5% NaCl.