Frequently Asked Questions
How did the conservator clean the fragments?
The fragments were soaked in a plastic bowl of hot water and washing powder for 20 minutes. The bowl was lined with a soft towel to cushion the pieces. Each fragment was then brushed with a good-quality hogs-hair stencil brush to remove the dirt. The solution must not be allowed to dry on the surface. The sherds were rinsed thoroughly in clean cold water, with a final rinse of deionised water. The process was then repeated. Finally, excess water was blotted off and the sherds left dry in a warm place. The fragments must be completely dry before reconstruction begins.
Were the old restorations removed?
Most of the old restorations had broken away when the vases shattered. Some still had fragments of porcelain attached, here seen as the bright white fragments adhered to the underside of the restoration. The fill is an off-white colour.
A few old fills still needed to be removed from fragments of porcelain, especially on the rim, or they would interfere with the new joins. Old painted fills were removed with a scalpel. After testing with various solvents, any residues were removed with dichloromethane.
What sort of stains were removed with a chemical poultice? How?
Stubborn stains that resisted the washing process (such as an old discoloured hairline crack across the bottom of one of the yan yan vases and dirt on break edges) were broken down with a chemical poultice. A sausage of cotton-wool soaked in a very weak solution of a bleaching agent (hydrogen peroxide) was laid along the join and the whole area wrapped in food-grade plastic film to prevent evaporation. The poultice was left for 24 hours. Afterwards the sherds were rinsed thoroughly.
Caution! When working with chemicals the appropriate Health & Safety procedures must be followed and protective clothing worn. Observe the written COSHH procedures.
Avoid using any chemicals on porous ceramic bodies such as earthenware. Mechanical cleaning methods are preferable here.