Fragmentary painted coffin from Abydos

If you are a member of the museum, you may have already seen some information about these painted coffin board fragments in the most recent issue of Expedition magazine:

E12505_2These fragments, which date to the Middle Kingdom (ca. 2000-1700 BCE), were excavated from the North Cemetery of Abydos in 1901 by John Garstang. The museum supported Garstang’s work through the Egypt Exploration Fund.

Despite the severe insect damage, the preservation of the painted details on these fragments is remarkable.

This fragment features 3 usekh collars, which were often reserved for nobility. Beside each collar is a mankhet, or counterpoise. The hieroglyphs above are the names of each of the collars, which are slightly different.

This fragment features 3 usekh collars, which were often reserved for nobility. Beside each collar is a mankhet, or counterpoise. The hieroglyphs above are the names of each of the collars, which are slightly different.

A detail of the usekh en nebti, the collar of the two mistresses that incorporates the uraeus and the vulture

A detail of the usekh en nebti, the collar of the two mistresses that incorporates the uraeus
and the vulture (7.5x magnification)

These coffin board fragments have never been exhibited, and our renewed interest in them is due to the fact that we are currently excavating tombs from the same time period in South Abydos, including the funerary complex of Senwosret III. You can read a lot more about this project in the recent Expedition issue and on the museum blog by following this link.

In order to exhibit the coffin fragments, they need some extensive conservation treatment. Their surfaces are dirty, the paint is cracked, cupped and lifting from the wood support, and is very fragile, and some of the boards are structurally unstable due to the extensive insect damage.

We are currently working on these boards in the lab, and we have made some good progress. We are cleaning the painted surfaces with a kneaded rubber eraser. The eraser can be shaped to a fine point, and working under the binocular microscope, it is possible to remove the dirt from most of the painted surface without disturbing the fragile paint.

We are using kneaded erasers (left) to clean the delicate painted surface of these coffin boards (right)

We are using kneaded erasers (left) to clean the delicate painted surface of these coffin boards (right)

Some areas of paint need to be stabilized before they can be cleaned. After testing a variety of adhesive solutions, I settled on my old friend methyl cellulose, a 2% solution of methyl cellulose in water to be exact, to consolidate fragile areas.

Paint consolidation is being carried out under the microscope with a fine brush

Paint consolidation is being carried out under the microscope with a fine brush

I am now working on testing some fill materials, both to stabilize the edges of lifting paint and also to stabilize the fragile wood. I will post an update as soon as I make some decisions and proceed with this part of the treatment!

 

Consolidating and reconstructing glass objects

* A new post from former Artifact Lab graduate intern Laura Galicier, contributing from a distance in Paris!

Reconstruction of a fish-shaped vessel from ancient Afghanistan (picture from a video of the British Museum, that can be viewed at https://www.britishmuseum.org/channel/exhibitions/2011/afghanistan/video_glass_blowing.aspx

Reconstruction of a fish-shaped vessel from ancient Afghanistan
- picture from a video on the British Museum website, that can be viewed by  following this link

Two glass objects from Cyprus were previously introduced to you. After an initial examination, several treatment steps were decided.

First, the surface showed evidence of delamination and was slightly flaking. We chose to consolidate the surface because if this destructive process went on it could lead to the complete loss of the object. An acrylic resin (Paraloid B72, that you’re now pretty familiar with) in acetone was chosen to do this light stabilization.

Then, we tried to see if the pieces from each object could be built up. We found that while the jug (n.63-1-196) would be able to reconstructed, the fragments of the bowl (n.63-200) didn’t fit together.

On the right: the glass jug    On the left: the glass bowl

The glass jug                                                                         The glass bowl

So the building work for the jug began! We had to find where every fragment was supposed to go. If you read our blogpost about the Egyptian Demotic jar, you’ll realize that building up a glass object is very different. Of course, the size of these glass fragments is considerably smaller than the jar fragments. Besides, the edges of a ceramic are irregular, which can help with reassembly, whereas the edges of glass are smooth.

Glass fragments glued together

Glass fragments glued together

In terms of thickness, a glass object can be very irregular, especially after deterioration, such as delamination of the surface. Generally, you hope that two fragments of similar thickness belong to the same area of the object, but with glass, delamination makes it possible for two fragments of very different thickness to fit together. Moreover, compared to ceramic, glass fragments have a very different way to adjust to each other.

Despite these differences, the methodology to reconstruct glass and ceramic has some similarities: it is necessary to map out the joins so as to know precisely where each fragment goes.

After a bit of work the fragments were put in the order to be joined.

The fragments arranged in the right order

The fragments arranged in the right order

Then, the fragments were temporarily reconstructed using scotch tape. Taping the joins clarifies where each fragment goes and exactly in which order to build them up. This order isn’t always the most obvious but if it isn’t respected, a fragment could prevent another one to fit.

The fragments were built together with scotch tape.

The fragments were built together with scotch tape.

Then, the scotch tape was removed and the fragments were glued with an adhesive (Paraloid B72). Three groups of fragments were reconstructed: fragments of the top, fragments of the bottom and a few fragments that should be placed in-between. The in-between fragments couldn’t be glued to the top or to the bottom because there’s a wide gap between them and the other fragments. This is why it was necessary to make fills so as to support these before going any further.

The three groups of fragments reconstructed and glued together.

The three groups of fragments reconstructed and glued together.

The fills will be explained in a post to come!

 

A sticky issue: choosing a consolidant for our painted coffin

In a previous post, I described some of the issues we’re facing in the treatment of our painted coffin of Tawahibre.

The top of the coffin before treatment – note the large losses and areas where the paint and gesso are just barely hanging on by a (plant fiber) thread

We’ve managed to clean much of the painted surface, but there are many areas of the paint and gesso that are so fragile, you get the feeling that a deep exhale – not to mention a sneeze – would send fragments flying. (And when I say gesso, I’m referring to the calcium carbonate preparatory layer/ground, which has plant fiber inclusions, that I’d like to investigate further).

Such areas require consolidation. We use this word, consolidation, a lot in conservation, and many of our treatments involve this process. Consolidation is essentially the reunification/reinforcement of a weak or powdery substance through the application of a material that we refer to as a consolidant. Consolidants often consist of dilute adhesive solutions, and they may be applied directly to artifacts with a brush or syringe, by spraying onto the surface, and in some instances, it may be appropriate to immerse an artifact in a consolidant solution. Ideally, a good consolidant must be stable (good aging properties), reversible (can be removed if necessary), and should not change the appearance of the artifact.

We have mixed up a variety of consolidant solutions to have on hand in the Artifact Lab – here are a few, along with some brushes, a plastic pipette, and syringes

Choosing an appropriate consolidant requires testing ahead of time. To start, it is important to test a variety of solvents (such as water, acetone, ethanol) – knowing which solvents can be used safely on a particular artifact will likely narrow down the range of adhesives that can be used (due to the fact that many adhesives are only soluble in a select number of solvents). In the case of our painted coffin, this involved testing all of the colors of the painted surface as well as the gesso substrate. Testing was carried out by rolling a swab dampened with each solvent over a discreet area and then observing the area for changes.

Solvent testing on an area of blue paint

After carrying out these tests, I did some research into what other conservators have used successfully for similar treatments on similar artifacts. In our field, we are fortunate to have a good body of published literature, and there is increasingly more information that can be found on the web as well. The sources I referred to included articles in the Journal of the American Institute for Conservation (JAIC), and a variety of books that have been published on the subject of conservation of Egyptian collections. Websites/blogs that I have found really useful include Inside the Conservator’s ArtA behind-the-scenes look at conserving Egyptian artifacts at the Phoebe A. Hearst Museum of Anthropology, conservator’s entries on the Brooklyn Museum blog, and the British Museum’s online collections database, which has many records with detailed conservation treatment information. There are actually lots of great blogs and websites out there, and I am grateful to my colleagues for actively sharing information in this way.

After this work, I selected several consolidants, and conducted another round of testing. During my testing I discovered that water was the key to getting the paint and the gesso to relax. Unfortunately, the painted surface is sensitive to water, but I found that a 50:50 mixture of water and ethanol is acceptable for use, especially when applied in a solution behind the lifting paint. In the end, we’ve chosen to consolidate the very fragile paint with a solution of methyl cellulose (a water-soluble cellulose ether) in a 50:50 water/ethanol mixture. To re-adhere larger flakes and chunks of gesso, we are experimenting using higher concentrations of methyl cellulose alone, and in combination with other adhesives, including Lascaux, a water-based acrylic resin.

An area near the foot of the coffin, before (left) and after (right) readhering detached gesso and consolidating paint

As I’ve stated before, this will be an ongoing project in the Artifact Lab – we will continue to report on our treatment progress, and any interesting discoveries made along the way (which is inevitable!).