Kaipure Catch Up

by Anna O’Neill

Hello again from the “Other Artifact Lab”! It’s been a while since we’ve checked in here from Kaipure’s tomb chapel and a lot has changed in Lower Egypt since the summer. Since June, we have been working to clean and stabilize the painted limestone walls of the Old Kingdom (2415-2298 BCE) mud-brick mastaba tomb chapel for a high-ranking Egyptian official named Kaipure. In the winter of 2015-2016, conservators Emily Brown and Madeleine Neiman worked to disassemble the tomb chapel wall from its wooden 1920s support and performed triage treatments (read more about that here) to keep the blocks safe from vibrations caused by construction next door. This past spring marked the start of the current phase of the project: cleaning and stabilizing the blocks so they can be moved to off-site storage in 2018.

If you’ve been through the Lower Egypt (Sphinx) gallery recently, you may notice some new and familiar faces in the lab. While Céline Wachsmuth and I (Anna O’Neill) have been working on the wall since June, in September we were joined by a third project assistant, Jonathan Stevens. 

The view from our lab space, with two of the blocks reflected in the foreground. We may be biased, but we think we’ve got the coolest lab-mate around.

Between all of us it’s been a very busy fall! We’ve continued to clean and stabilize each individual block from the wall, becoming familiar with some different techniques for cleaning, consolidation, infilling, and documentation, as well as repair methods used by the ancient Egyptians (more on these later). Dr. David Silverman, Curator-in-Charge of the Egyptian Section, stopped by to tell us a little more about the history and imagery of the chapel. We’re also improving our proficiency in fork lift handling as we move the pallets supporting the very heavy stones. Just a few weeks ago, we reached a very important milestone – we officially passed the halfway point, with more than half of the 59 blocks stabilized for their move off-site next year.

A view inside the lab. The largest blocks (up to 700 pounds!) are housed on the red shelves along the back wall; the ones covered in tissue are cleaned, consolidated, and ready to move off-site.

If you find yourself in Lower Egypt any time soon, you are welcome to come watch us work in the lab and read more about the history of Kaipure’s tomb chapel (on our new, informative signage!). While we don’t have open window sessions downstairs, we do occasionally find ourselves in the main Artifact Lab and we’ll be happy to talk about our work then. We’ve got more Kaipure blog posts planned, so keep your eyes open for updates and insights.

The Kaipure Conservation Project is funded through a generous grant from the American Research Center in Egypt (ARCE) Antiquities Endowment Fund (AEF) which was established though a grant from the United States Agency for International Development (USAID).

Cleaning – it’s complicated

by Lynn Grant

Not that long ago, a museum colleague was heard to say “I suppose cleaning counts as conservation” in a doubtful voice. We conservators found this both appalling and amusing as cleaning is a huge part of what we do. And knowing when and how to clean is a big part of our education. Using the wrong methods can permanently damage an artifact. Those of us who finished our conservation training more than ten years ago mostly relied on the rule of thumb ‘try gentlest methods first’. But there have been rumblings in the field about better ways to do things, with terms like Modular Cleaning Systems and Gel Cleaning drifting by. Clearly this was something we needed to know more about.

Richard Wolbers (in blue polo shirt) demonstrates basics of cleaning gel production to Museum conservators and interns

Fortunately for us, one of the ‘rock stars’ of gel cleaning research, teaches nearby at the Winterthur/University of Delaware Program in Art Conservation. Richard Wolbers, who describes himself as a ‘Cultural Materials Engineer’ to reflect his interest in applying new ways of thinking about conservation issues, is Associate Professor at WUDPAC and has graciously lent us his expertise on specific projects previously (one example here). But now that we have so many conservators and interns working on different projects and with a major campaign to reinstall our Egyptian Galleries after 90 years about to start, we asked Richard to give us a two-day workshop on the basics of gel cleaning. This was an abbreviated version of week-long workshops he gives around the world but we certainly squeezed a lot of learning into two jam-packed days.

The conservators and interns get into gel (and emulsion) production!

Richard has basically turned much traditional conservation ‘wisdom’ on its head: looking deeply into the complex interactions among surfaces, dirt, and cleaning materials and using his observations to develop new approaches to cleaning. Even gels aren’t the new frontier anymore; custom made emulsions may allow conservators to use water and solvents in combination when the surface is easily damaged by them when used in liquid applications. Many of the techniques and materials that Richard uses come from the cosmetics and food industries. In fact, as we listened to his explanations, I kept thinking of the Molecular Gastronomy movement. Some of our new cleaning tools have as much relation to our old way of doing things as this does to your grandma’s chicken soup:

Chicken soup spheres (http://jordancaterers.blogspot.com/2013/07/chicken-soup-spheres.html)

It’s a brave new world for conservation cleaning….

A final look at Ptah-Sokar-Osiris

Julia Commander is a third-year graduate student in the Winterthur/University of Delaware Program in Art Conservation. She is currently completing a curriculum internship at the Penn Museum.

When we last checked in with the Ptah-Sokar-Osiris figure, I was working on finding a satisfactory cleaning approach. The figure has a darkened layer over the front surface, which obscures the beautiful patterns, colors, and hieroglyphs. My goal for cleaning was to clarify designs and improve legibility, although the sensitivity of the paint layers has made this an interesting challenge.

After cross-section analysis, I looked into instrumental techniques to better understand the condition issues. One promising technique was gas-chromatography mass-spectrometry (GC-MS) since the darkened layer was potentially a coating material. I took a sample by swabbing the dark layer from the wood substrate. Since only a small amount of material can be gathered this way, I collected several swabs in a glass vial for analysis. I sent this down to Winterthur Museum’s Scientific Research and Analysis Laboratory (SRAL), which has previously collaborated on samples from the Artifact Lab. Dr. Christian Petersen, a GC-MS specialist, sent back my spectra with some interesting results. He described the mixture as “waxy dirt,” which helps to clarify what likely happened to the surface. Wax may have been applied to consolidate the badly flaking paint, and this layer could have trapped dirt over time as the figure rested face-up in storage.

Focusing on the wax component did not immediately produce better cleaning results, and I continued testing gels with variations on solutions, application method, and timing. I eventually tried an application of Pemulen TR-2 gel, a polymeric emulsifier, with a proportion of solvent added. This gel was more effective for lifting the waxy grime and did not require excessive action on the surface. Used along with a silicone solvent barrier layer, I was able to lightly clean without lifting pigments from the surface. While I had some initial ideas about cleaning, this method was something that I only found through the process of trial and error.

L-55-29 detail, cleaning test

Even though I cleaned slowly in very small sections, the actual treatment step took much less time than the research, testing, and planning phases. Take a look at the results below.

L-55-29, before cleaning (left) and after cleaning (right)

Aside from cleaning, a few other steps were taken to stabilize the statue. The headdress, which is constructed from multiple pieces of wood, had a large gap that allowed the pieces to move individually. To add support and decrease movement, removable fills were made from Volara foam and Japanese tissue. These materials were turned into small “pillows” that were then pressure-fit into place.

L-55-29 headdress, shaping and fitting Volara foam fills

The figure, headdress, and base do not fit together in a stable arrangement. Instead of intervening further with the object itself, an exterior mount will be constructed to hold the components in place. This method has worked well with a similar Ptah-Sokar-Osiris figure, which you can see displayed in the Upper Egypt Gallery!

Another Ptah-Sokar-Osiris figure on display in Upper Egypt, showing the back of the figure and the mount holding the three pieces together.

Overall, this project provided quite a few challenges and an opportunity to explore cleaning techniques. Thanks for following along on this experience with Egyptian painted surfaces!

The treatment of (half of) a yellow coffin

This week, we finally finished the treatment of the lower half of our 21st/early 22nd Dynasty yellow coffin.

A view of the interior of the coffin before (left) and after (right) conservation treatment.

A view of the interior of the coffin before (left) and after (right) conservation treatment.

The treatment mostly involved cleaning the interior surfaces to remove dust using a soft brush and HEPA-filtered vacuum, and cosmetic sponges. Here’s another view to give you a better sense of just how much grime had accumulated in the interior of the coffin:

A detail of the head of the interior of the coffin before (left) and after (right) conservation treatment.

A detail of the head of the interior of the coffin before (left) and after (right) conservation treatment.

There was also a fair amount of flaking and lifting paint, which needed to be stabilized. We used 1-2% methylcellulose in 50:50 water/ethanol to consolidate flaking paint, and Japanese tissue paper and 5% methylcellulose to fill gaps.

In the course of the treatment, I have also continued to research the significance of the holes drilled into the bottom of the coffin, which can clearly be seen in the overall images at the top of this post, but here is another look:

An overall shot of the coffin bottom, with a detail of 4 of the holes below.

An overall shot of the coffin bottom, with a detail of 4 of the holes.

I’m anxious to start working on the lid of this coffin, which will inevitably provide more information about this object and it’s history. We should be able to bring the lid from storage up to the lab sometime this summer, and I’ll post images of it as soon as it arrives. In the meantime, I have enjoyed researching these types of coffins and finding images of similar ones in other collections (like this one at the Petrie Museum, this one at the Houston Museum of Natural Science, and this “remuddled” coffin at Stanford University) which is helping me gain a better understanding of these coffins and the contexts in which they were made.

Spring cleaning?

It may be a little early for spring cleaning, but no matter what time of the year, there is not much that I find more satisfying than a good, deep clean (on a grimy artifact). Last week, Tom Stanley (the museum’s Public Relations/Social Media Coordinator) posted this image on the museum’s Facebook page, which shows some cleaning in progress on an Egyptian painted wooden coffin here in the Artifact Lab:

coffin board cleaningHe also posted this on our Instagram page.

Here is a before treatment image of the coffin board (which is in 3 separate fragments):

E12617A-C, boards from a painted wooden coffin

E12617A-C, boards from a painted wooden coffin

While Tom was in the lab taking photos, I promised him that I’d put some additional information about this project on the blog. I thought this would be a great opportunity to take another video with our binocular microscope, kind of like the video I captured of the paint consolidation on the shabti figures I worked on awhile ago.

To see the process of how we go from

————————–this————————–to————————–this————————-

corner before after

click on the link below.

Cleaning an Egyptian painted wooden coffin from Molly Gleeson on Vimeo.

In the video, you’ll see (at 7.5X magnification) that I first used a soft-bristled brush to remove loose sediment and dust from the surface, by brushing directly into the nozzle of a variable suction HEPA-filtered vacuum. Then I used a cosmetic sponge to further, gently, lift away grime from the surface. Finally, I used a kneaded rubber eraser to remove the grime that is more embedded in the painted surface.

Okay, so I’ll admit that this may not be as cool as the video of Conservator Tessa de Alarcon laser cleaning a stone table from Ur (this one is hard to top), but it’s pretty gratifying nonetheless.

I’m currently trying to learn more about this object too, by checking into our museum records. I’ll keep you posted.

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!

 

The Outer Coffin of Ahanakht – part 2

One of the boards from the inner coffin of Ahanakht, before treatment.

Previously I began to tell you about this multi-part artifact. Then, I was just starting to get acquainted with it. When conservators first look at any artifact, the first thing we think about is not where it’s from, not how old it is, not even what culture made it. The first and most important fact for conservators is what it’s made of. The material tells us what kind of problems it might have and what kind of treatments we can use or not use – it’s the starting point of everything we do.

The coffin boards are wood, with some paint applied. Four thousand year-old wood. Right away, that tells us something about what kind of wood it must be, since wood generally doesn’t survive so long in the archaeological record. Because there’s been a lot of research done on Egyptian materials, we can say with some confidence that the wood is cedar of Lebanon (Cedrus libani). Cedar is a prized wood because the trees produce chemicals that make them resistant to insect damage and various forms of rot.

A detail of the board showing construction details.


The first step of any treatment is careful examination. The coffin boards, despite being entombed thousands of years ago in the desert environment of Egypt and then brought to Philadelphia with its humid summers and desiccating winter heating seasons, appear to be in excellent condition for the most part; their most obvious problem being a thick coat of dust from uncovered storage for many decades. I documented the appearance of the board, noting its construction details, such as four wooden pegs and mitered edges. One curious feature was thin metal ribbons running in channels along the long axis of the board. I was unsure whether these were an original feature or something done in modern times to put the coffin back together. It seemed an unusually elaborate repair but the metal was in such good condition that I didn’t think it was 4000 years old. Even under a microscope, I couldn’t tell exactly what the metal was. There were slight traces of green corrosion, which usually means copper or copper alloy, but the metal was mostly dark grey and quite flexible, so it could be lead. I made a note to analyze it using our new portable X-ray fluorescence analyzer which has since happened and to do some research on Egyptian coffin technology. Dr. Joe Wegner, also an Associate Curator in the Egyptian Section, recommended a book about a similar coffin at the Boston Museum of Fine Arts (The Secrets of Tomb 10b) and there I found this information: “the sides have beveled edges fastened together by dowels and copper ribbons“. So it looks like those metal ribbons are original. Perhaps their unusually excellent condition has something to do with the cedar around them.

During treatment, showing dirt partially removed and tools used for cleaning.


Treatment was relatively straightforward. I used a HEPA-filtered vacuum with variable speed control to remove the loose dust from the surface of the board. Conservators choose their cleaning methods based on the type of dirt to be removed and the substrate from which it is to be removed. ‘Dry’ cleaning methods (those not using liquids such as water or other solvents) are generally less likely to damage the artifact and are preferred wherever possible, although care must still be taken to ensure that only the dirt is removed and not any of the original surface. By using a very small vacuum attachment at low speed and monitoring the process closely using a magnifying visor, I was able to clean the surface safely. Not very glamorous but I’ve discovered that this artifact has a pretty important role in the history of archaeological science – see my post on the Museum’s blog for information on that!

Painted wooden coffin of Tawahibre

By now, many of you may be familiar with this object from it’s appearance in our recent media coverage:

Painted wooden coffin from the Late Period

This is a painted wood coffin from the Late Period, post-558 BC. It has been fairly inaccessible in storage until coming up to the Artifact Lab. Now that it’s up here, we’re realizing that it’s going to be a complex project, in more ways than one.

First of all, it’s a bit confusing who this coffin belonged to. In our records, is listed as the coffin of Tawahibre or Teker-Wah-Eb-Re. The mummy associated with the coffin was x-rayed in 1932 and examined in the 1970s and both times determined to be a woman in mid-adult life (about 40 years old). However, in 1946, the hieroglyphic text on the coffin was translated as identifying a male court official, the son of J-se(t)-N-Ese. Our curators are going to work to translate the text to see if we can figure out who the coffin belonged to…however…

The second complication is that, unfortunately, this coffin hasn’t aged particularly gracefully, and it is now very fragile and in poor condition. And even more unfortunately, the areas that contain much of the text are in the worst condition, with major losses to the painted surface.

Detail showing major paint loss across the foot area of the coffin

So, one of the first things we’ve done to improve the condition of the coffin and aid in translation is to remove years of accumulated surface dust using a soft-bristled brush and a HEPA-filtered vacuum. This made a big difference and already allows the text to be read more easily. I am now conducting cleaning tests to see how much more surface grime can be removed. I did some dry-cleaning (meaning cleaning without the use of solvents like water or alcohol) testing today using Groomstick, a natural rubber product similar in consistency to SillyPutty, and cosmetic sponges, and I’m pretty happy with the results. Look at how much more dirt I was able to remove with these products:

Partially cleaned surface (left) and bits of Groomstick and cosmetic sponges after dirt removal (right)

Next I’ll have to start addressing how to approach the stabilization of the fragile and flaking paint and gesso and unstable wood elements.

Posted by Molly