Samantha Alderson, Soraya Alcala, Judith Levinson, and Madeleine Neiman
A group of 19th-Century monumental painted wooden carvings was cleaned in connection with the recent major renovation of the historic Northwest Coast Hall at The American Museum of Natural History by a team that included conservators trained in both objects and paintings, working in consultation with additional conservators, scientists, and descendent community members. The project included a set of four poles and a figure from the Tsimshian nation of northern British Columbia and Alaska and one Nuxalk house entry pole from the Bella Coola valley of British Columbia.
The carvings, ranging from 6’–15’ in height, had been on continuous open display in the museum for 100 years or more, and their polychromy had become significantly obscured by multiple layers of aged museum-applied coatings and heavy soiling. Previous testing had not found a satisfactory method for cleaning without damage to the fragile paint below and many questions remained about the nature of the paint and coatings and their relationship to each other.
The surfaces were complex and varied, thus no one cleaning methodology could be effectively employed. Based on testing the team implemented a combination of different materials and techniques, modifying protocols depending on the demands of the surface. Most of the cleaning was accomplished using macroemulsions containing pH-buffered water, a chelator, a water-immiscible solvent, and xanthan gum whose components could be adjusted as needed. In addition, Nanorestore® cleaning fluids and hydrogels, and the non-woven micro-filament textile Evolon were utilized to address specific areas.
In the end, the team was able to successfully reduce the coating and grime layers on all six poles, greatly improving their appearance and legibility. In addition, research conducted in collaboration with conservation scientists at partner institutions aided in the understanding of coatings and underlying paint, and their relationship to each other.