“Recent Investigations into a Mechanical-Chemical Method for Removing Corrosion from Furniture Brass” Delivered by Delphine Elie-Lefebvre and Mark Anderson, paper by Delphine Elie-Lefebvre, Richard Wolbers, Elena Torok, Mark Anderson & Stephanie Auffret
OK, I have to admit that part way into this talk I rather regretted putting my name in to blog about it. It had a lot of information and a lot of chemistry in a short amount of time, and I couldn’t hear the speakers very well. I recommend looking into a future article I hope the authors will publish with their fascinating experiments and findings.
The talk was the story of “observation, discovery and reverse-engineering” to evaluate new methods to clean brass furniture mounts on wood substrates. Brass is often damaged from commercial products and overcleaning with abrasives. The authors came up with and tested protein glues made into peel-off gels to remove corrosion, cleaning products and grime from brass. They tested different types of glues and gelatins at different pH, applied with Japanese paper and peeled off after 20 minutes. Then vinyl erasers were used afterwards to further reduce corrosion.
Through their discussion of the analysis they carried out, which threw me back to first year of graduate school and made my heart race from nerves, they suggested that some of the components of corrosion (which were removed from the alloy at different rates) bound with the amino acid components in the protein glue. The physical removal of the glue by pulling produced an even appearance on the brass and this suggested that chemical cleaning was part of the effectiveness of the treatment. Further cleaning with the erasers was made easier by the first part of the treatment.
Copper-alloy coupons were used to test different glues at various pH along with controls. The authors hope to carry out more tests to come up with analytical results that show more definite differences between coupons. These methods, however, have a lot of potential for furniture and objects conservation. It looks like it must take some practice, and there are a lot of variables to test, but for a big cleaning project, this is one to put in your treatment repertoire.