THE CONSERVATION OF WET MEDIEVAL WINDOW GLASS: A TEST USING AN ETHANOL AND ACETONE MIXED SOLVENT SYSTEM
D. R. GRIFFITHS, & A. M. FEUERBACH
Definitive evaluation of the success of any treatment is difficult when the treatment has not been subjected to detailed scientific investigation. On the basis of present evidence, this method is considered successful for a number of reasons. The pieces that were transparent before treatment remained so after treatment, although it should be noted that they were not highly deteriorated. The pieces that were highly degraded and prone to crumbling before treatment were strong and solid after treatment. No painted decoration was obscured, and in some cases, where the glass was very deteriorated, the darkness of the glass lightened, perhaps due to filling of microscopic cracks in the glass matrix, and the decoration previously unseen became visible as darker areas on the surface. These improvements were observed immediately after treatment and still applied when the stored fragments were checked five years after their treatment. Badly deteriorated pieces that were washed and air-dried but not consolidated (as a control and as material for potential future analysis) crumbled even as they were lifted into storage bags.