ARCENCPostings

Wednesday, January 20, 2016

Initial treatment of the wooden boat model | In the Artifact Lab


http://www.penn.museum/sites/artifactlab/2016/01/18/initial-treatment-of-the-wooden-boat-model/

Alexis North is the Project Conservator for the Egyptian Storage Move Project, Penn Museum.

Since my first post, I have been working steadily on stabilizing the painted wooden boat model. For a bit more background, this boat model was excavated from Sedment, a cemetery site about 100km south of Cairo.

Map of Egypt showing the location of Sedment and other cities. Source: Google Maps

A number of First Intermediate Period (2250 – 2061 BCE) tombs were uncovered, including that of Khentkhety, a middle-aged man who was buried in a shaft tomb with a separate burial chamber that was bricked up after interment. Sir Flinders Petrie, the archaeologist who excavated at Sedment, described Khentkhety’s tomb as “the finest burial that we found,” (Petrie and Brunton 1924, 11) even though it had been robbed in antiquity. His mummy was placed in a rectangular wooden coffin, similar in style to the coffin of Ahanahkt. According to Petrie, the wood of the coffin was so damaged by termites that it could not be moved. A detailed colored drawing was made as a record of the interior decoration, which was elaborate:

Colored drawing of the interior of Khentkhety’s coffin, depicting offerings to the deceased. Source: Petrie and Brunton 1924

Several wooden models were also removed from Khentkhety’s tomb, including two boats, a granary, and several human figures. The boat model I am currently treating, which represents a sailing boat, was found on the ground outside the burial chamber, where it had been either moved or dropped by the tomb robbers.

To return to the present day, the first and most obvious issue which needed to be addressed for this model was the actively lifting and flaking paint. In order to determine the best materials and procedure to follow, I and some of my fellow conservators performed spot tests with water, solvents, and adhesives. This involves applying a very small amount of each material to an inconspicuous area of the object to be treated, and watching for any reaction, like darkening or staining. Luckily, the surface of the boat model did not react negatively to any of the materials tested, and I was able to move on to treatment.

I began by consolidating the paint on the exterior sides of the boat. I wanted to stabilize the sides first because it was very difficult to handle or move the boat at all when so much of the exterior paint was so fragile. For each lifted area, I started by applying a drop of ethanol, which cuts the surface tension and allows the consolidant to flow more easily underneath the lifting paint. Then I used a very small brush to apply 1% Methylcellulose in deionized water. The water in the adhesive helped to relax the lifted paint, and after a few minutes I could gently push the area down until it made contact with the wood underneath. It is a bit difficult to see in photographs, but the consolidation has worked really well so far in relaxing and readhering the paint:

Before (top) and after (bottom) consolidating the areas of lifting paint.

I am also keeping a detailed record of where I am applying the consolidant. Documentation is an important part of conservation treatment, so future examiners know what is original and what has been added to the object over time. These records can also alert a conservator to any additional changes in the object’s condition.

An annotated image showing all the spots I consolidated, what material I used, and where I performed spot tests.

In working closely on the exterior surface, I have seen several areas where it appears a resin or surface coating was applied. I do not know right now whether this is ancient or modern material, but that is something we may be able to find out in the future using different analytical techniques. What I can see now is that these areas show preferential damage, where the applied material has shrunk and become brittle, pulling the paint away from the wood beneath it.

Image of the bottom of the back of the boat. The green areas indicate where the applied resin has run down the bottom, and there is now preferential loss to the paint in those areas.

If the material is modern, I may decide to try and remove it before it can cause further paint loss. If it is an ancient application, however, we want to preserve it as part of the object’s construction. The areas will be documented carefully, and monitored for future changes.

I have now finished the sides of the boat, and am moving on to the top, where some of the most significant flaking is. I will be back with another post soon to show the progress!

 

Sources:

Horne, Lee. Introduction to the Collections of the University Museum. Philadelphia: University Museum, University of Pennsylvania, 1985.

Petrie, W.M.F. and Brunton, G. Sedment. British School of Archaeology in Egypt Publications, v.34/35, 1924.

http://www.ucl.ac.uk/museums-static/digitalegypt//sedment/index.html