We performed conservation treatment on the Thomas Jefferson statue in front of the Columbia University School of Journalism. Sculpted by William Ordway Partridge and erected in 1914 the bronze elements and limestone base required cleaning and conservation treatment.
The bronze elements had experienced weathering resulting in protective wax failure, green and black corrosion. Once these elements were cleaned of failed wax and loose corrosion the bronze was spot-patinated with dilute solutions of sulfurated potash (liver of sulfur) and ammonium sulfide to create a consistent, historically accurate patina. New coatings of sacrificial wax were applied and polished. The failed joint between the bronze figure and stone base was packed with lead.
The limestone base exhibited general soiling, graffiti, areas of copper staining, and gypsum crust accumulation. The base was cleaned of soiling with a non-ionic detergent and clean water. Graffiti was removed with paint strippers. Chemical poulticing helped to reduce the copper staining and the gypsum crust was manually removed. A written plan for continued maintenance was created to help reduce future deterioration and to increase the longevity of the conservation treatment, thereby reducing future costly conservation treatments.