Flaky, crumbly, and fragile: approaching the treatment of our painted coffin

Overall shot of our painted coffin, before treatment

Okay, you have heard a lot about PUM I lately, but there are other things going on in the Artifact Lab as well! Awhile ago, I wrote about the painted coffin of Tawahibre we have in the lab, that is in poor condition and is requiring significant conservation treatment.

This has been an ongoing project in the lab, as visitors may have noticed. I am not the only one working on this – treatment of this painted coffin has turned into a group project, and conservators Lynn Grant, Julia Lawson, and Nina Owczarek are also working on the coffin during their time in the lab, usually on Sundays.

Before I write a little bit about what we’ve been doing, I wanted to mention the fact that I’m referring to this object as a coffin, and not a sarcophagus. I have heard others – both museum staff and visitors – use both words when referring to it, and I have caught myself doing it too, and I thought this could be a little confusing. I am going to stick with the word coffin, because coffin typically refers to the container closest to the body, while a sarcophagus (which I read derives from the Greek for “flesh-eater”, apparently from a Hellenic belief that some stone used for body-containers actually consumed its contents!) refers to the outer case. Sarcophagi are also essentially rectangular, while coffins can be rectangular or anthropoid (meaning human-shaped) – our coffin is anthropoid.

Okay, now that we have that out of the way, I’ll start telling you what conservation treatment has been carried out on our coffin so far. I wrote in my previous post that after full documentation, we removed accumulated dust from the surface with a HEPA-filtered vacuum and a soft brush. Then, after some test-cleaning, we continued to clean the coffin using cosmetic sponges. While I was originally finding success cleaning the surface with Groomstick, it ended up being too sticky for fragile areas, and the cosmetics sponges work just as well, and especially in very small, delicate areas.

A section of the coffin before (left) and after (right) cleaning with a vacuum/brushes and cosmetic sponges

This initial cleaning has made a huge difference. There are a lot of areas on the coffin, however, that cannot be cleaned until they are stabilized. There are many areas where the paint, along with some of the gesso ground, is cupped and lifting, or completely displaced.The exposed gesso ground in these areas is very fragile and crumbly.

An area on the coffin where the paint is cupped and lifting away from the surface, revealing the gesso ground below.

In other areas, the paint and ground have completely separated from the wood substrate.

A large piece of paint and gesso that has separated from the wood below.

After a lot of testing, we have started stabilizing, or consolidating, the flaking and displaced paint and gesso with a very dilute adhesive solution. We are also re-adhering loose and detached pieces of gesso and wood. In my next post, I will describe the testing involved in choosing adhesives, the treatment methodology that we’ve developed, and some of the complexities we’re facing in treating this fragile object.