Correcting past electrolytic reduction

I have been working on 3 foot tall, 16th century Islamic gilded
copper candlestick. It appears that it was cleaned with electrolytic
reduction, which went wrong. The surface, the gold in particular, is
covered in a salmon-pink redeposited copper layer. I have had
limited success in removing the deposit with ethanolamine and
polishing compound. I have tried dilute acids (nitric and formic),
EDTA (ethylenediaminetetraacetic acid), ammonium carbonate, and
Rochelle salts. Does anyone have any other methods to remove or
reduce this deposit?

Kathryn Etre
Andrew W. Mellon Fellow - Objects
Detroit Institute of Arts
5200 Woodward Ave.
Detroit, MI 48202
313-833-1728


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                  Conservation DistList Instance 22:44
                 Distributed: Sunday, February 8, 2009
                       Message Id: cdl-22-44-012
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