AIC's 46th Annual Meeting

Lead has been used for centuries as a filling agent for a wide variety of materials ranging from metals, to ceramics, and even teeth. It’s flexibility, low melting point, and ability to form alloys with a variety of common metals made it an ideal conservation material before the health hazards of lead were well known. As a result, lead fills can be found in a large number of museum artifacts. Despite the prevalence of historic lead fills in collections, there is little published information on how to contend with historic lead fills in modern object conservation treatments. Of particular interest for the authors is the interaction of more current conservation fill materials with lead repairs. This presentation will focus on the challenges encountered in working with in-situ lead fills, as demonstrated through the case study of an outdoor, cast bronze sculpture of Mercury currently on display at the Huntington Library, Art Collections and Botanical Gardens in San Marino, CA. With this object, the authors not only had to contend with damage to the bronze caused by leaching lead corrosion, but also the unforeseen complications involved in attempting to apply new, modern fill materials on top of the preserved historic fills. Health and safety concerns were also a consideration when developing the treatment plan, as the complete removal of the lead was not an option due to lack of disposal facilities and suitable protective equipment. In the end, a treatment methodology was developed through trial and error that, while using somewhat unorthodox materials for museum object conservation, resulted in a treatment that preserved the original fills, stabilized the sculpture for outdoor display, and vastly improved the aesthetic appearance of the bronze.