Evaluation of the protectiveness of an organosilane coating on patinated Cu-Si-Mn bronze for contemporary art

•Protectiveness of organosilane coating (PropS-SH) on patinated bronze was assessed.•Patina of cuprous oxide and sulphide does not protect the bronze against corrosion.•Both sprayed PropS-SH and Incralac® offer a good protection to patinated bronze.•PropS-SH shows excellent performance under UV light and simulated outdoor exposure.•Higher wettability of PropS-SH favours its penetration in porous patina structure.