Planning and experimentation

May 13, 2010

We have spent the last few days reviewing our plans for filling the gaps and our colleagues have been experimenting with materials to do the first part of the filling.

Julie and I had identified three sorts of fills to be done: structural fills of large missing areas (yellow in photograph); small cosmetic fills along joins that had been made back in February (green); and removable cosmetic fills along the seams between the large segments that are not physically joined (red).

Annotated photograph showing the three sorts of fills planned for C 396.

The structural fills would help stabilize the relief as well as filling out its appearance.  The cosmetic fills would be done to allow the viewer’s eye to appreciate the artistry of the carving without being distracted by dark join lines.

Our colleagues from China had brought with them samples of stone and stone powder from quarries near where the stone in our reliefs would originally have come from.  By combining this material with a stable resin, we would have a sympathetic fill material for the ‘green’ fills.

Jars of acrylic resin and stone powder with test samples of various combinations in paper cups below. The stone powder is identified as coming from Shaanxi, FuPing, North Mountain.

Our approach may have been slightly different without access to this stone powder – we usually mix the resin with glass microballoons (microscopically tiny hollow glass spheres which are inert and lightweight) and then paint the resulting white fills.  Our colleagues tried various mixtures of resin, stone powder, and microballoons but preferred a recipe that included only stone powder and resin.