Reducing the thickness of each fragment
A dental drill was used to remove the excess mortar from the back of the material. This was found to be an efficient and reasonably speedy if messy technique. The respirator shown in the photograph provided a safe environment for the conservator during this process.
The fragment ready for mortar removal.
The fragment some three millimetres thick.
The fragment backed with glass tissue, P.V.A and inert filler
The fragment ready for reassembly
When the material had been reduced to a thickness of about three millimetres it was then easy to flatten distorted and fragmented assemblages. Where fragments were badly damaged it was possible to repair the backing with synthetic plaster, made with P.V.A and inert filler, as soon as this had hardened, glass tissue was cut to size and cemented with the synthetic plaster to its back.
After the passage of a day or so the consolidated and backed fragments were then stable enough to have the facing-up material removed. The fragment was turned over and a pad dampened with acetone laid on its front surface, after a few minutes the adhesive was softened enough to enable its removal without any damage to the paint layers.
The fragment reinforced with synthetic plaster
The rear surface of the fragment.