The practical use of lasers in removing deteriorated Incralac coatings from large bronze monuments

The bronze monument (approximately 83Cu: 10Sn:4Zn;3Pb) had been vandalized repeatedly and suffered decades of corrosion and lack of maintenance when the monument was first treated in 1997. The protective Incralac coating-applied in the 1997 treatment-had begun to fail in 2003. The surface was chemically cleaned of failed coating using solvent based poultices and steam, then repatinated with a mixture of ferric nitrate and potassium permanganate to approximate the original color. It was retreated with BTA and coated with Incralac.