In the objects conservation lab this week: we have a beautiful, though heavily tarnished, 19th C silver bowl in the lab being treated before going on display next year. This bowl is elaborately decorated with repoussé detail. The small details can be difficult to polish, and some polishing materials can get stuck in the crevices. For this piece, polishing will start with applying a thin paste of calcium carbonate and ethanol to the surface with cotton swabs. Once the ethanol evaporates, a stiff bristle brush is used to easily remove the powdery calcium carbonate from crevices. This method will remove the bulk of the tarnish from the surface. Any residual tarnish will be buffed away with a soft polishing cloth. In the photo you can see the difference between a polished area, closest to the bottom of the photo, and an unpolished section that still retains is dark tarnish layer. Once finished, the piece will be stored in a silver storage cabinet which is lined with materials that inhibit tarnish and maintain the polished surface for display.
Bowl, 19th Century, Southeast Asian/Asia, silver, Bequest of Marjorie Schiele, 2008.150