Coolness vs. cuteness

Update – this post contains outdated language. We no longer use the term “mummy” and instead use “mummified human individuals” to refer to Ancient Egyptian people whose bodies were preserved for the afterlife. To read more about this decision, follow this link.   

We have been carrying out our work in front of the public here in the Artifact Lab for nearly 4 years now. Despite the fact that visitors can peer in from various points around the room and watch us working for as long as they have the patience for it, it’s not always clear what we are doing, especially when the work is very detailed and only requires us to make the smallest of movements for hours on end (several of us have overheard museum visitors quietly whispering “is she real?”).

So even though we are “demystifying” our work by bringing it out in full public view, we sometimes have to rely on labels, signs, a slideshow we have running here in the lab, and, hey! this blog, to describe what it is we are doing.

For example, I have been working on this Ptolemaic pectoral cartonnage piece, and most recently started backing and filling losses and tears in the linen support. Most of what I’ve done so far is really difficult to see or appreciate, even though I’m working right by one of the lab windows.

Detail image before (left) and after (right) filling a loss

Detail image before (left) and after (right) filling a loss

These images above show a detail of an area that I backed and filled. There is nothing elaborate or dramatic about this work. As you can see, the fills are small and subtle, mimicking the surrounding areas of paint loss. These repairs were made by backing the losses with Japanese tissue paper and filling with a mixture of Klucel G, alpha cellulose powder, glass microballoons, and powdered pigments.

There are a few areas that I could not access from the front, so I decided to flip the piece over to continue the treatment. In order to protect some fragile areas while the piece is turned over, I temporarily faced them with small pieces of Japanese tissue impregnated with Paraloid B-72.

A detail of the upper half of the pectoral showing facing in progress

Below, you can see what the piece looks like from the reverse. Unfortunately, this means that for the time being, visitors will not be able to see the beautiful painted decoration.

Reverse of E352

Reverse of E352

But have no fear! We have other interesting things on view, and to keep us company as we do this detailed, subtle work. We have our mummy Hapi-Men, who is front-and-center in the middle of the lab, and for those visitors who may not see the “coolness factor” of the mummies, there is this little guy who is currently sitting right by one of the lab’s windows:

E11474: Ptolemaic cartonnage cat head from Abydos

E11474: Ptolemaic cartonnage cat head from Abydos

Because who can resist a cute kitten? We sure can’t, which is why we figure that if this adorable kitty is in the window, even if our work doesn’t appear particularly exciting at the moment, there will be something interesting for everyone to see (and the cat head actually does need treatment and a new storage support, so he is up here for a real reason too!).

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!

 

Ungluing, re-gluing and filling the jar.

Statuette of an egyptian potter at work (beginning of  the 2nd mill. B.C).

Statuette of an egyptian potter at work (beginning of the 2nd mill. B.C).

The next step for the Egyptian jar was un-gluing all the fragments …to glue them together again.

We had two different cases: fragments that remained adhered together and fragments that were already separated, bearing remains of an old adhesive on their edges. The old adhesive had to be removed since it had many negative issues. First, it prevented the fragments from being joined back together by creating an unnecessary thickness at their junction. Moreover, when reconstructing the ceramic, the old adhesive prevents the fragments from fitting together well.

This old adhesive had a light brown color and after a few tests, it was found to swell when warm water was applied on it.

Here is what it looked like:

Detail of the break edge of one of the fragments, after applying water steam.

Detail of the break edge of one of the fragments, after applying water steam.

To remove the adhesive from the break edges, we used a Preservation Pencil, a tool looking like a pen and emitting water steam. Once softened, the adhesive was very easily removed with a scalpel or a brush.

And here is the result :

The same fragment edge after the removal of the old adhesive.

The same fragment edge after the removal of the old adhesive.

For the fragments still adhered together, it was a little more difficult since the water had to penetrate inside the jar but not too much because of the water-soluble ink on the surface. Compresses, or poultices, of water were applied on the interior of the ceramic, to cover the breaks. Most of the fragments fell apart quite quickly contrary to areas where the jar was very thick.

Now the building could begin ! … well almost since it was necessary to plan precisely how to proceed and in which order to arrange the fragments. First, we had to find where each of them was going, to estimate the losses. For that purpose every fragment was given a number and they were located on a map so as to keep track of their location.

The map; the numbers were indicated on the fragments with blue scotch tape.

The map; the numbers were indicated on the fragments with blue scotch tape.

Then the gluing really began, using the conservator’s favorite adhesive: Paraloid B72, diluted in acetone.

First steps of the gluing.

First steps of the gluing.

The more the jar grew, the more it needed a support, first on the outside, since its bottom is rounded….

A good support was provided by this bucket filled with glass balloons, heavy enough to stabilize the jar.

A good support was provided by this bucket filled with glass balloons, heavy enough to stabilize the jar.

…then on the inside to prevent it from collapsing on itself because of some particularly heavy fragments.

The jar was growing and needed internal support; the white material inside is a plastic bag filled with polyethylene fiber.

The jar was growing and needed internal support; the white material inside is a plastic bag filled with polyethylene fiber.

Losses in the ceramic had to be filled at the same time as the gluing to provide structural support to the jar and prevent it from collapsing.  Moreover those areas to fill would have been difficult to reach once the gluing was complete.

There was one large loss that definitely needed to be filled since one of the surrounding fragments was holding by only a few millimeters to another one.

Filling this area was a bit tricky. The fill material needed a support to be applied on the jar. Japanese tissue paper was glued inside of it and strengthened by applying several layers of Paraloid B72. It also needed to be shaped according to the curve of the jar.

On the left: The area to be filled.                        On the right: Japanese tissue paper used as a support to hold the fill material.

On the left: The area to be filled.  On the right: Japanese tissue paper used as a  support to hold the fill material.

On the left: The inside of the jar with the "tricky fragment" held in place by the japanese tissue paper.   On the right: Applying the fill material.

On the left: The inside of the jar with the “tricky fragment” held in place by the japanese tissue paper. On the right: Applying the fill material.

The fill material used is a mixture of Paraloid B72 and glass micro-balloons, looking like a very light white powder; plaster is also traditionally used to fill losses, but glass micro-balloons are lighter and don’t bring any salts to the ceramic. That kind of fill is also reversible and completely neutral towards the ceramic.

Here’s the fill once finished and polished with a heat spatula, ready to be painted.

The fill almost finished: the building can go on.

The fill almost finished: the building can go on.

More fills and building to come in a next post !