ConNext-2021

76 The Conservation Treatment of the Clock Case of an Organ Clock produced by Charles Clay KEYWORDS: Charles Clay, conservation, restoration, organ clock, Georg Friedrich Händel. In 2016 Museum Speelklok (Utrecht) acquired a prestigious organ clock which was produced in the late 1730s by Charles Clay in London. The oak carcass of the clock case is veneered with mahogany and ebony. It is ornamented with gilt bronze decorations and brass mouldings. The arches of the dome are framed by gilt bronze ajour screens. The clock dial is incorporated into a large copper plate elaborately decorated with sculpted silver elements in relief and an oil painting. The musical mechanism consists of an organ that plays a variety of airs by Georg Friedrich Händel (1685-1759). The movement of the clock and its organ mechanism have been restored by the conservators of Museum Speelklok. This paper focuses on the treatment of the clock case. The mahogany veneer of the case was loose, with some lacunae. The carcass wood of the panels and the plinthwas cracked, and the veneer in these zones was blistering. The metal decorations were dirty and corroded. The surface of the painting was dirty, and there were small lacunae in the paint layer. The high gloss and reddish hue of the transparent varnish on the clock case were considered very disturbing. Inspection with ultraviolet light in combination with py-GC/MS analysis revealed that the glossy finish was shellac that had been applied after the removal of the original finish. Museum Speelklok collaborated with the Rijksmuseum (Amsterdam) to assure that the case would be restored in such a manner that its original appearance could be appreciated and the high quality of materials and craftsmanship be apparent. The non- original high gloss finish on the pedestal was removed with solvents. Cracks and lacunae in the veneer and solid wood were filled, and loose parts were consolidated. Beeswax was chosen as a finishing layer to enhance the rich figurative pattern of the mahogany. The metal decorations were cleaned and polished to a soft gloss. Dirt was removed from the surface of the painting, and the lacunae were retouched. The result is a successful example of an interdisciplinary treatment. t.mol[at] rijksmuseum.nl