Examples of restoration/conservation work carried out on stoneware objects including the use of 3D printing in conservation.
Case study for the Yixing stoneware vase using 3D printing
Vase dimensions 30.6cm x 14cm.
A rare 17th century Chinese Yixing stoneware vase with loose rings handles.
The vase was missing one of its loose ring handles.
The assessment and treatment of the object should not affect the condition of the surface patina as this is an indicator of age and also an important aesthetic factor that adds to the historical, symbolic and financial importance of the object.
Research was undertaken to find a material/technique that could be used to make a new ring that would not affect the surface of the object. The only damage to the vase was the missing ring which was had a diameter of 5cm and had an incised spiral travelling around it 54 times, the option of making a model of the ring in wax and then cast would be very time consuming and expensive, The undamaged ring could not be removed from the object but could possibly be used to take a mould from. Research into moulding materials that would not affect the surface was carried out, test tiles were done but no suitable material was found. Research concluded that it would be a viable option to make a 3D print of the ring that could then be used as a master to cast the handle from in a suitable material.
Once the master had been produced the ring was made from an epoxy resin, it would appear very similar to the original ring, weigh slightly less but would not feel cool to the touch like stoneware, this would allow the owner to differentiate between the 2 rings to show an honest treatment and address the issue of forgery. A 2 part mould was made of the master so that the join travelled along the spine of a spiral, the inner edge of each mould was spliced so that it could be gently opened and painted with the bulked epoxy resin. The cast sections were then fine filled and retouched with French chalk, synthetic onyx powders, dry powder pigments and matt acrylic polymer varnish to create the right surface finish. The vase was wrapped in a protective film and the 2 cast sections were bonded in situ. Some sanding and hand retouching with acrylic emulsion and dry powder pigments was carried out.