2025 Poster Session

This poster looks at silicone rubber as a tool for silver polishing and tarnish removal. Silicone rubbers mixed with calcium carbonate as ‘polishing erasers’ have possible applications on artworks with mixed media components or fragile sections that pose challenges to traditional polishing methods. Three types of silicone rubber were sourced from Smooth-On to test efficacy and control on tarnished silver surfaces. The three rubbers under review are Sorta-Clear 12, Mold Star 30, and Equinox 40. All three silicone rubbers are platinum-cure and can be easily mixed by volume with a 1A:1B ratio. Each rubber was chosen for its specific Shore A hardness (ASTM D-2240). Sorta-Clear 12 is 12A, Mold Star 30 is 30A, and Equinox 40 is 40A, with the higher number denoting a harder rubber. Each rubber was cast into bricks with different amounts of lab-grade calcium carbonate mixed into the rubber during its pot life. A variety of cast and cut shapes of the cured rubbers, application lubricants, and clearing solutions were tested. This poster will review the process of mixing the rubbers, the addition of calcium carbonate, and the evaluation of each mixture’s ability to safely remove tarnish. Implementations of this tool will be discussed, as well as possible advantages and disadvantages.