Islamic bowl reconstruction

The Islamic bowl was difficult to reconstruct. It had many issues with it: large gaps, worn or broken edges, and laminated pieces. 

Top: Front of bowl, with gray areas indicating plaster; Bottom left: Back of bowl, with grey areas indicating plaster; Bottom right: pieces after disassembly.

I started with the easy part, the rim, and worked my way inward. The rim was mainly intact, but even so, there were weak joins and unstable sections. I glued each section together, placing the sections in a box of glass beads, which acted like a sandbox, to prop the pieces up. While the Paraloid B-72 dries, you want the join to be horizontal so that gravity helps keep the pieces in place. I then mounded up tissue for a support when I put the rim sections together.

Left: sections of the rim standing in glass beads; Right: the completed rim.

I put on as many pieces as possible, but then it became hard to place the pieces exactly. I then switched to gluing the small slivers together to create larger pieces. The center is mainly intact, but there are only a few places where a sherd touched both rim and center, and none of those had good join edges. 

Small sherds grouped into larger pieces, drying against a weight.

Claudia called Stephen Koob, a ceramics conservator at the Freer who has written books and articles on ceramic reconstruction methods. He said that he has seen a Seljuk bowl with laminated pieces, though not as bad as mine. It could be as issue with a particular clay or firing. He suggested using a synthetic material called Flügger to gap fill. Flügger is like plaster, but it is more flexible and stays workable for longer. It is used more in Europe than in the States, though it started to be used fairly recently.

To cast the bowl properly, all the joins had to be perfect and the angle of the sherds correct. I decided the best way to do this was to break up the rim into six sections and fix each before putting them back together. I used acetone to dissolve the worst rim joins, then I used a hairdryer to heat up the thermoplastic adhesive on each join to manipulate the pieces back into shape. I also heated and fixed the joins on the smaller interior pieces.

I made a new support for the bowl out of carved foam, cotton, and tissue. I used a razor and scalpels to carve out the general shape of the bowl from the pieces of thick foam. I cut a large depression in the middle so that the top of the base was level with the sides of the bowl. This was padded with cotton, then a sheet of tissue was placed over top.

Carving the foam.

I nestled the pieces into the support and pinned them in place. The central section was quite stable, but it took some work to get the rest of the ceramic to fit. I left off the top pieces of laminated sherds. When they lay over a back section, I cannot put the pins in place. The first time I tried to put all the rim and back pieces in, I was left with a centimeter-wide gap which I physically could not close. I took the pieces all off, padded the support again to change the angle of the sides slightly, then tried again. This time, I was able to close the gap and get all the pieces to fit. Although it is still not exact, the pinned pieces looked good.

Top: First attempt, with a large gap in the rim on the right; Bottom: Pieces pinned into the support.