Tag Archives: painted limestone

An update on Kaipure’s funerary chapel

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By Jessica Betz Abel and Julia Commander

Greeting everyone – there’s a lot to update on from our Conservation Lab Annex (CLA) but for this post, we’re going to focus on the recent progress of Kaipure’s Funerary Chapel. It has been a while since we posted about Kaipure, in fact the last time we posted was almost exactly three years ago. As a quick reminder, two of the walls (the south and east) from the chapel were most recently on display in the Lower Egyptian Galleries, but they were disassembled and deinstalled in 2015 as a precautionary measure due to nearby construction. This also allowed us to proceed with much needed treatment of the flaking limestone and paint as well as designing a new support system in anticipation the entire chapel being reassembled in the new Ancient Egypt and Nubia Galleries. The complete chapel has not been on display in over 25 years!

Here at CLA we are working on building one of the smaller walls as a proof of concept for our engineering team. The south wall is the smallest section and so that is where we decided to start. But before we could begin, we had to locate all the blocks and bring them down from the rafters. 

Julia Commander using the forklift to retrieve blocks from the south wall of Kaipure.

With all the blocks needed for the south wall, we started by erecting the bottom course of stones. Once those were in place and shored up with temporary wood and foam pegs, we laid the first stretcher course on top.

The first two courses of the Kaipure chapel south wall.

In antiquity stones would have been assembled using a mortar, however, using a mortar in an indoor gallery setting is not necessary or practical. Mortars require quite a bit of water for application and that could potentially mobilize any lingering salts in the limestone which could compromise the structural integrity of the stone. Mortar is also much less reversible than many of our other options, not to mention the mess it would create during installation. Instead, we have been investigating interfaces of various materials that would replace the need for mortar or adhesive at all. For Kaipure, we have narrowed down our options to Silicone Rubber and Sorbothane. Both materials have good viscoelastic properties, reduce point loading, distributing the weight of the stones, and providing a grippy material between each course to lock the stones together.

Comparing the working properties of Sorbothane vs. Silicone Rubber.

In addition to the interfaces, we are currently working with our project engineers to design an armature on which each wall can be assembled. The armature will provide the stability and support that many of the individual stones need. In order to not cause any further damage to the stone, we are opting to use the existing holes which were drilled into the backs and sides of the stones during a previous installation. Though we are still very much in the early stages of design we are excited by the prospect of seeing the entire chapel reunited in a few short years!

Transformation Tuesday, Stela Edition

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Sometimes the simplest treatments make the most visible impact! This Eleventh Dynasty (2081-1938 BCE) painted limestone stela from Deir el-Bahari in Egypt had a thick and yellowed coating dating from before it was installed in our Lower Egyptian around 1958. It came off easily by swabbing with acetone, followed by a simple cleaning with a xanthan gum/benzyl alcohol gel to remove any remaining dirt. Plaster from where the edges been set into the gallery wall was carefully chipped away with a chisel. Suddenly, the ibis looked much younger than its 4,000 years!

Many thanks to Tom Stanley, the museum’s Social Media guru, for making this transformational GIF:

We should note that, in conservation, cleaning is considered an “irreversible” treatment – that is, there’s no putting back what you’ve cleaned away. So we’re always careful to make sure that anything we remove is something that shouldn’t be there. This is especially important when the cleaning process is as dramatic as the one above, since you can’t change your mind once you’ve started! From the way the coating was applied over the break edges, it was clear that it had been put on after the stela was excavated. That meant that the coating could be removed and the ibis will be much nicer to look at when it’s reinstalled in the renovated Egyptian Galleries.

58-10-1 before, during and after treatment.

A typical Tuesday in Kaipure

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Anna O’Neill, Assistant Project Conservator

The Kaipure lab space in the Lower Egypt (Sphinx) Gallery lets visitors observe as conservators work on a tomb chapel wall, but we don’t often have the opportunity to explain what’s going on. So, here’s a glimpse into what we might be doing on any given day.

9:00 am: We arrive in the conservation hallway, drop off our bags and grab a quick cup of tea to warm up before our weekly department meeting.

9:15 am: Department meeting! It’s getting a bit crowded in here with so many conservators working on lots of different projects. We give our updates – “Still working on Kaipure” – and listen to everyone report their progress. Since we spend most of our time working in the Lower Egyptian Gallery, it’s fun to hear all about all the various objects being treated.

10:00 am: Céline finished up the block she was working on yesterday, so our first order of business is to put her completed block back on the red shelves along the back wall and pull out a new pallet for her to work on.

Jonathan brings Big Joe into the lab.

10:15 am: We’ve completely rearranged the lab, clearing space in the middle and in front of the shelves so that we can bring in Big Joe, our forklift (no, really – his name is written on the side). Most of the time, people tend to think of conservation as a very delicate task, but we’ve had to become experts in heavy machinery, too.

Carefully maneuvering Big Joe to pick up a pallet with a completed block.

10:30 am: We use Big Joe to move Céline’s completed block to a shelf, measuring to make sure that it fits, and then raise the tines all the way up to the top shelf. It’s the first time we’ve had to reach this high, so we’ve brought in Bob Thurlow, Special Projects Manager and resident forklift expert, to supervise while we bring down a new pallet. Fortunately, everything goes smoothly and we land the pallet on a wheeled table made specifically to hold the heavy weight of the blocks.

Left, Céline pulls a block from the top shelf – it’s eight feet off the ground, but feels much higher! Right, Making sure the pallet is centered on the rolling table.

10:45 am: It’s time to play Jenga with our workspace again as we put Big Joe back in storage and get our tables back in working position.

11:00 am: Céline begins documenting her new block, which means getting to know every inch of the object. She begins photography and condition mapping, while Jonathan and I get back to work on the pieces we already had out.

12:30 pm: Lunch time!

1:30 pm: We’re back in the lab, each working on our blocks. Céline has finished documenting her new block, so she gets started on the first phase of cleaning – dusting with a soft brush and gentle vacuum.

Jonathan is busy with solvent cleaning, painstakingly rolling tiny cotton swabs saturated with acetone or ethanol over the surface to remove soiling, staining, and other substances that may have accumulated over the nearly 100 years the wall was on display.

Everybody busy at work in the Kaipure lab.

I’ve done all the cleaning I can on my block and now I’ve moved on to stabilizing loose and lifted flakes of paint and stone. This is done by a process we call “edging”, using a syringe to apply a mixture of Paraloid B72 bulked with glass microballoons and fumed silica to fragile areas, then gently shaping it with a solvent-soaked swab so they fill any gaps between flakes and the stone surface. These tiny fills serve multiple purposes: they fill empty spaces so they won’t collapse under pressure; they protect the edges so the flakes won’t be popped off if touched; and they provide light adhesion between the flake and the stone. Once inpainted, the B72/microballoon mixture blends right into the stone, but we feel much better knowing that the surface is more stable.

5:00 pm: The guards are making their rounds in the gallery to make sure all the visitors have left for the day. That means it’s time for us to close up the Kaipure lab for the evening and head home.

All photos by Lucia Scanlan

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).

#Transformation Tuesday ft. The Big Guy

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By: Céline Wachsmuth

It’s #TransformationTuesday! And that means I get to show off a wonderful transformation that happened right in the Lower Egyptian gallery here at the Museum.

Before Treatment Shot of the Big Guy

After Treatment Shot of the Big Guy

Tah-dah! Looks great, doesn’t it? The Big Guy looks so much better. (I affectionately nick-named this block “Big Guy” because it’s the heaviest block on this side of the wall (it weighs approximately 720 pounds). If you’re in need of some context for this project, check out this Kaipure Catch Up)

Though there isn’t much visible difference between these two photos, in terms of the stability of the block’s surface, much has changed. All in all, this treatment took me about two months to complete and it was quite the journey.

I began my treatment by condition mapping the block in Photoshop and then surface cleaning with gentle vacuuming. Once the dirt immediately on the surface had been removed, I used a variety of sponges and erasers to clean the more stubborn grime. In just these first two steps I realized how fragile much of the surface was. Small flakes would break off easily and not always predictably. Swabbing with a cotton swab was no different and in some cases was more problematic. I proceeded slowly and carefully. Once the Big Guy had been safely cleaned, you could really see his brightly painted surface. The colors were more visible, but so were the fragile and lifting areas. I next faced the biggest challenge of this treatment: how to efficiently and effectively stabilize and consolidate the surface.

Photoshop Condition Mapping of the Big Guy

I began stabilizing all the lifted areas by injecting a dilute adhesive under the surface using an insulin syringe. This worked for some areas but caused some of the surrounding surface to darken. If it came in contact with the surface, the needle also had the potential to disturb it and cause a piece to break off. I then tried to apply the adhesive by brush; I saturated the brush with adhesive and gently tapped the exposed stone next to the prepared surface, wicking the adhesive underneath. This worked but had many of the same issues as the syringe. Both application methods would have taken a substantial amount of time, as almost all of the surface was in need of some consolidation. I began to explore other options for effectively consolidating the surface. In speaking with conservators in the department, we decided to try applying the adhesive via spray canister.

Preval Spray System

Before spraying the entire block, we tested it to see how even the spray application would be and if it would cause any darkening or staining. I was very happy with the tests but thoroughly discussed all the potential shortcomings of this application method with Kaipure project supervisor Molly Gleeson. Spraying the adhesive wouldn’t penetrate below the prepared layer and would only provide superficial consolidation. For those areas that were significantly lifted, I went around with a higher percentage of adhesive and used the brush method of application mentioned above. Once I was satisfied those areas had been stabilized, I sprayed a layer of adhesive on the surface, let it dry completely, and then applied a second layer in areas that were still more concerning. The Big Guy was much more stable and happier but you can’t see any evidence of this because the adhesive is clear!

(I bet if you ask him though, he’d tell you he felt much prettier!)

This figure grabbed a bunch of food to celebrate the Big Guy’s transformation! In actuality, this figure is bringing food for the REAL Big Guy, Kaipure

The Big Guy was almost complete but I had one more task to finish before he would be ready to be handled. Many areas of loss had unprotected edges at risk of being lifted off the surface. Take this area for example, there are quite a few spots with unprotected edges ready to break off with added pressure. 

Detail of unprotected edges

To solve this problem, I edged (put up a protective and supportive layer of material around the exposed edge) those spots with Modostuc. Notice the white spots now on his body?

Can you see the white areas?
Detail of area of edging on figure

I went around to the many places on the Big Guy with unprotected edges and did the same thing. Once I was satisfied all edges had been protected, I painted over all of them with watercolors, a process called “inpainting”. And, if I did my job well, you can’t see it!

Can you find the areas of edging?
Detail of inpainting

The Big Guy is now stable and ready to be moved off-site until the next phase of treatment: re-installing him in the Museum with his many brothers and sisters! This is all part of a larger picture of transformation (for more information on the museum Building Transformation Campaign, click here). It’s a transformation inside a transformation! Inception, anyone?

Two weeks ago, conservator Alexis North posted about one of her recent treatments where the before and after treatment photos are indeed worlds apart and more what you might expect from a Transformation Tuesday post (see her post here). However, don’t judge a book by its cover or an object by its treatment photos! Though you can’t always see the changes, rest assured that once an object passes through conservation it has been changed for the better. Stay tuned for more of our exciting (and perhaps surprising!) Transformation Tuesday series posts!

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).