By Rebekah Engelland, Maryland Archaeological Conservation Laboratory Intern
During my summer internship with the Maryland Archaeological Conservation Laboratory (MAC Lab), I learned much about the conservation of archeological materials. As a pre-program conservation intern looking at graduate schools, I knew very little about conservation practices. I first focused on the treatment of iron, spending time in the air abrasive unit (essentially a microscopic sand blaster), practicing on non-archeological iron that had corroded. Once I felt comfortable with the air abrasive unit, I moved on to iron from archeological sites that required conservation. The next step in treating iron is to remove the chlorides, one of the critical components to rust. Every week I had to check the amount of chlorides in six different containers as the salts were extracted from the artifacts and drawn into a caustic solution.
Following iron, I learned how to clean copper alloy artifacts, which involved using a scalpel under a microscope to remove soil and corrosion until I came down on a stable patina layer. I also cleaned white metal artifacts (tin, aluminum and lead) and applied a protective coating once no more soil or corrosion remained. For silver-plated items, I learned to use electrolytic reduction, an electrochemical technique, to help take off the outer layer of tarnish and limit the amount of polishing before I applied a protective coating of wax. Lead required a different approach, and I used electrolytic consolidation to reduce the corrosion on the surface of the lead artifacts.
Throughout the summer, I also had the opportunity to go out into the field and help on projects. MAC Lab Conservator Heather Rardin and I had the chance to see a laser cleaning demonstration at the Fifth Regiment Armory’s World War I Memorial in Baltimore, where the Conservation of Sculpture and Objects Studio, Inc. removed previous paint layers and dirt from both bronze and stone with a laser custom-built for conservation. One of the assistants let me try out the laser to clean a few feathers on one of the bronze eagles.
At the Alexandria, Virginia waterfront, MAC Lab Head Conservator Nichole Doub and I helped Alexandria Archaeology’s team with on-site conservation as they deconstructed a ship’s hull before an underground parking garage was built. The ship, along with two others, was deliberately sunk to be part of a late 18th century wharf. By the time I joined the project, the team was removing the ship’s timbers using a crane. Nichole guided the deconstruction process, making sure the team did as little damage as possible to the remains of the ship. We returned a couple days later and helped the team remove the ship’s keel, which I helped strap to the crane. It was incredible playing a small role in saving a part of Alexandria’s history.
On another excursion, Heather and I went to the Prince Frederick courthouse and helped Howard Wellman Conservation LLC treat three statues. The marble and limestone bases were treated with a biocide and then scrubbed down. To coat the bronze statue, we used a blow torch to heat up the metal. Then we applied a protective layer of wax with the brush, heating it up more with the blow torch to remove the brush strokes. These treatments would protect the statues against both corrosion and biological growths, though they would need to be repeated every few years.
Over the summer I received an extensive education on archeological and object conservation from the amazing staff at the MAC Lab. This experience makes me feel much more prepared to apply to graduate conservation programs. I want to thank everyone at the MAC Lab for taking the time to teach me and making this a truly incredible internship.