Saturday, July 14, 2012
Behind the Scenes of EBAP: Conservation
In order for the excavation to be successful, artifacts have to be preserved and analyzed. I had the amazing opportunity to work with our conservator Vicky and learn how to mend ceramics, store significant finds, and remove very tough concretions. One of the main skills of a conservator is to be able to join together broken pottery sherds. Piecing together pottery is one of my favourite activities that I've experienced here, but it can be very difficult. Reconstructing a ceramic vessel is like doing a puzzle without the picture and (in most cases) you're missing the majority of the pieces. After a few days of practice I found a few tricks that made the process easier. The most obvious joins are fresh, which is inevitable during the process of excavation. These are easy to tell apart because the break edges don't have any concretions on them. Shape of the break edge, curvature of the sherd, and area of the vessel (such as a rim or a base) also are ways to tell if sherds join. Any decoration such as painted bands or a motif can show if two sherds are close together or on the same area of a vessel even if they don't join. The main way to tell if sherds will join is to be patient and try fitting them together even if I didn't initially think they would. When two sherds join they "key in" and fit together perfectly so it is obvious when they do. It's very rewarding finding joins, and it is so interesting seeing how the vessel comes together. When I start I have a vague idea of how the shape of the deep bowl or stirrup jar should be but every time I finish a vessel I'm surprised with how the sherds ended up fitting together. Once the joins have been found the next step is to prep pottery sherds to be glued, and to learn how to break down glued joins with a solvent in case of a mistake. The break edges are prepped with a very diluted adhesive. Once they are dry it is time to apply the adhesive and let it set (which usually involves being a human vice). After the sherds are all glued the extra glue is taken off with a small amount of ethanol. It is extremely important to have all of the joins laid out and to start from the rim or the base. If even one piece is "locked out" and cannot fit where it should either the one join or the whole vessel has to be broken down with a solvent, which means I would have to start over again. The tools used to reconstruct pottery range from scalpels to paint brushes.Scalpels are used along with ethanol to take off concretions that could be inhibiting a join from fitting together properly or from absorbing the adhesive. Concretions can also be covering decorations that could help with finding joins. Paint brushed are invaluable as they are used to apply adhesive to joins, clean off surfaces, and prep break edges. Conservation does not only focus on pottery, but all artifacts we discover. Vicky has to be able to identify materials and know how to protect them. There are many aspects of conservation that I would love to learn more about.