Stone Conservation, Sculpture Conservation, Architectural Features Conservation;
In 1908 Scottish-American sculptor John Massey Rhind carved four Tennessee pink marble sculptures for the front of the Birch Bayh Federal Building and U.S. Courthouse in Indianapolis, Indiana. These four large sculptures represented Industry, Agriculture, Literature, and Justice. Over a hundred years later, McKay Lodge Conservation Laboratory is involved in the conservation of the sculptures. We have assessed, maintained and treated the marble sculptures whenever needed.
Periodic attention to these beautiful statues is necessary due to the poor quality of the original stone as well as the adverse impact of rainwater on the sculptures. Structural flaws, known as stylolites, are one major cause of deterioration of stone.
Each sculpture exhibits a large number of stylolites in the form of irregular veins running across the block of stone. The stylolites contain various insoluble minerals, including iron. Oxidation causes the iron deposit to rust which in turn stains the surface of the sculpture.
In addition, the marble in stylolite-adjacent areas is particularly friable and prone to crumbling. In the past, the sculptures exhibited numerous small-size losses of the original marble surface, as well as a large number of deep cracks and fissures. These cracks made the sculptures particularly vulnerable to water damage. Immediate attention to losses and cracks is critical in preventing serious damage.
The latest assessment was performed in June of 2018. McKay Lodge Stone Sculpture and Architectural Features Conservator Marcin Pikus found the sculptures to be in very good condition. Only minor soiling of the surface was found, some rust staining from the stylolites and a few areas of failed pointing mortar.
Pikus and conservation assistant Curtis McCartney then cleaned all four sculptures using a hot water pressure washer combined with a biocide to deter biological growth. The rust-bleeding stylolites were removed with chisels and grinders. These shallow surface losses were recreated with a special limestone restoration mortar. For the final step of the Massey Rhind conservation treatment, the areas of failed mortar were chiseled out and joints were re-pointed with color-matched mortar.
Utilizing conservation methodologies the after treatment results left the surface of the outdoor marble sculptures rejuvenated and with greater structural stability for the long term.