A new comprehensive concept for the conservation of stained glass windows

Two materials, complementary to each other, were developed for the application in conservation of stained glass windows: Inorganic gels, prepared by sol-gel techniques, offer a promising new method for the consolidation of endangered paint layers. The fixation material was tailored for good adhesion to glass and long-term stability. The development and characterization were carried out on test pieces simulating loose paint on non-corrosive glass. First results of adhesion tests confirm the consolidation effect of the material. Further investigations on its efficiency on corrosion-sensitive model glasses and originals will be carried out before recommending the method for the restorer's workshops. The supplementary protective coating is based on a heteropolysiloxane (ORMOCER) in combination with inorganic fillers. The laboratory test phase of this system is considered to be completed. The two new materials can be combined to a new comprehensive conservation concept: local, irreversible fixation of endangered paint contours and reversible protection of the whole glass surface by extensive application of the ORMOCER coating.