Conservation of excavated artefacts
Depending on the country and the institution, the field of conservation can be divided into separate branches. We at the Metropolia University of Applied Sciences have different lines for art, textiles, paper, furniture, organic materials and objects. My line is objects, which covers a whole range of different materials and all sorts of items you can think of.
Inside objects conservation we don’t specialize in any particular material; that usually happens in the work life. A possibility to concentrate on archaeological material would be very useful, since that special niche is a world of its own and requires a lot of know-how about many materials and methods. So ever since we had courses on conservation of archaeological metals and waterlogged wood, I have taken every opportunity to delve deeper into this wonderous field. But enough of school, let’s go to work.
One of the first rules of conservation of archaeological objects is that they are usually in worse condition than they appear to be. I’ve had plenty of hands-on experience on this one, as many small corroded metal parts that I’ve been working on have suddenly broken apart or cracked, and showed their inner works, which might be nothing but a matrix of corrosion products. On other occasions an artifact at hand might be covered in such a hard crust (corrosion products and soil particles fused into one), that no ethically viable method of cleaning can penetrate it. In many cases these two opposites combine: A friable object whose cleaning needs more force than it can handle.
An important aspect when cleaning the artifacts is a question of how much to remove? Back in the old days when conservation ethics was unheard of, one method of cleaning a rusty metal object was to heat it red hot and quench it in oil or water. This sure did remove all of the corrosion layers, but also the original surface of the object, thus losing intrinsic information. The original surface might be nothing but corrosion products and as such can be very hard to spot, so when taking away the crust it is imperative to go about it slowly and meticulously.
The question of how much to remove also links to the significance of the object. Conservation work in general revolves a lot around meanings and historical information. What do we want to show with this object? What is its ideal state? Does the object itself hold a special importance or is only the information of what it is significant? As an example, laborious conservation of two hundred wrought iron nails from a 19th century excavation site hardly is worth the trouble. In this case, the amount and type of the nails is propably more important than the individual objects. Of course, defining this is more up to the archaeologist than the conservator. Seamless co-operation in this matter would be very important, so that conservation resources can be used efficiently.
Hanko 1941 -project has been a great opportunity for me to learn. The material finds from the excavations are numerous albeit mostly relatively simple without the need for complex conservation procedures. The fact that there are lots of buttons, hooks and discarded pieces of broken objects, has enabled me to rehearse the much needed manual skills that are vital in my field. It’s not all unimportant clutter, though. Sometimes the odd artefact pops up that gives new insights into the lives of the people we are researching about. And those are the moments when I really need to stop and think before lunging into work.
On the one hand conservation of archaeological objects is difficult and painstaking, but on the other hand very intriguing and rewarding work. Every cleaning procedure of a formless crust is a mini excavation of its own. What does it hold inside? Is it something unique? Does it have labels, stamps or other readable information? How well has the material preserved underneath all the dirt and rust? I am certain there are many stories, many suprises waiting for us beneath the surface in Hanko.
Chain to a rifle barrel cleaning kit found in war grave 6 (body 6) before and after consevation. Photo Jarno Huusko for the Hanko 1941 project.