In our first quarter class, CAEM 260: Structure, Properties, and Deterioration of Ceramic, Glass and Glazes, we were assigned a ceramic object on loan from Southwest Museum of the American Indian Collection, Autry National Center to examine, document, and treat the following quarter. I was given a low-fired, light-colored Chiriqui vessel whose largest condition issue was its fragmentary state; the vessel was in 5 large fragments with additional small pieces in an accompanying bag (Fig. 1). As I would soon learn, assembling a broken vessel is not simply putting a puzzle back together and finding which pieces go where. The stress released as a vessel is broken can result in fragments that don’t quite meet up to complete the object as it was before—and I learned exactly how frustrating it can be to achieve tight and aligned joins with stubborn objects like this!
Joining my vessel (with 40% Acryloid B-72 in acetone using a brush) went quite well in the beginning, such as with Fragments C and E (Fig. 2).
I determined the best sequence would be to join Fragments C-E-A and Fragments B-D (Fig. 3).
These two sections would then come together to complete the vessel…however this didn’t prove to be as easy as I had thought. I found that while one side of the join was well aligned and tight, the other side by comparison was like a mile-wide fissure as far as I was concerned (Fig. 4); a jolting discovery for a newbie in training! The two sections just didn’t fit, despite careful and tight joining of the fragments that comprised them.
Any ideas I had about merely adding adhesive and piecing the vessel back together were naively simple and optimistic in hindsight, but fortunately lab manager and conservator, Vanessa Muros, was able to guide me through a more complicated (and at times scary!), multi-stage aligning method involving heat and pressure. The misaligned fragments were adjusted using a hair drier (set to a low temperature) to soften the B-72, and then pressure was applied using 3M Coban self-adherent wrap and soft-grip clamps, with barriers of thin Ethafoam and Volara (Figs. 5-6); slow tightening of the Coban wrap was performed regularly using a wooden popsicle stick. This process may seem simple, but pressure was required in multiple directions and aligning one area often caused another to move and misalign; all joins had to be considered. It became a battle over control between what I wanted the fragments to do and how they naturally wanted to be, all while gauging the safety of the object and determining when enough was enough.
In the end, relatively good joins were achieved overall (Figs.7-8). The changes that occurred from the stress released upon breaking still prevented perfectly tight and aligned joins everywhere, but the best compromise was achieved and the results were more than satisfactory. I was able to learn about the unforeseeable problems that can occur during the treatment of ceramics, and I gained a greater feel for the material and how it behaves…and I’ll be ready for the next one!
by Heather White (’16)