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The Copper Lab

December 4th, 2009

Whitney Minger

MA Student, Program in Maritime Studies

Maybe it is the Christmas colors of red gleaming copper along with a green corrosion that made the copper lab feel festive. Maybe it was the sudden revelation of words on a copper button, a hyperlink to the past, that made the history and archaeology students in Hist 6840 excited during the copper lab. Several different things made this lab interesting and it was truly enjoyable to use a little elbow grease and a few simple ingredients to produce a stable, beautiful artifact. This was the best part for me, Whitney Minger, a graduate student in the Maritime History Department. I received a BA in Anthropology from the University of Hawaii and spent two years working as a CRM Archaeologist. Like most archaeologists, I find it extremely satisfying to remove sediment, or more recently, corrosion products and find a clue to the past and have recently discovered the satisfaction of preserving those artifacts for the future.

The first portion of the lab treatment was conducted on objects not from the archaeological or historic record. The students were to test various polishing and stripping techniques on a cheap hardware copper rod. The rods had been corroded on purpose for the experiment, through the addition of chlorides. Each student was to use Calcium Carbonate, Haggerty 100 as a polish and Citric Acid as a stripping agent on the corroded and tarnished portions of the rods. The results were varied and some students preferred Haggerty 100, while I personally preferred the Citric Acid on the tarnished portion, and Calcium Carbonate on the corroded portion.

The second portion of the lab treatment was conducted on objects recovered from the Hayes House near Tryon Palace. These artifacts were excavated during an ECU archaeology field school under the direction of Dr. Ewen. Numerous artifacts needed conservation and the basic procedure was to mechanically clean the artifact using bamboo sticks and dental picks, chemically clean sediment and corrosion product with an acetone spot treatment and finally apply coating for long term preservation of the artifact. The first coating was 3% Benzotriazole and acetone which worked as a corrosion inhibitor. The second coating was 10% Paraloid B-72 and acetone which worked as a sealant, protecting the artifact from common sources of deterioration. During this experiment, many students, including myself, realized that their plain copper buttons had designs and/or writing under the corrosion layers. It was satisfying to realize that through our efforts, we were providing additional clues to understanding the Haye’s House site.

Overall, it was wonderful to uncover the past, learn about the conservation treatment of copper and assist Dr. Ewen in preserving these artifacts which are a part of our North Carolina cultural heritage.

General Conservation

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