124 The painting „Death of St Joseph“ to remove both the salts as well as the superficial dirt in one operation. The back of the painting was cleaned first with strong bristle brushes and vacuum cleaner followed by a treatment with Wallmaster sponges. Consolidation of the paint layer Because of the unfavourable climate conditions on the island (high humidity and salty atmosphere). and negative experiences with animal glues in previous conservation projects, it was decided to use a synthetic consolidant to consolidate weak areas of preparation and paint layer. Best results were achieved using Plextol B500 in H2O and ethanol in a 1/0,5/0,5 ratio. The addition of ethanol made it possible to minimize staining on the back of the painting.81 With consolidation, the paint layer achieved acceptable stability and cupping deformations of the paint layer were significantly reduced. Removal of varnish and mismatching overpaint Solubility tests for the removal of the varnish layer were executed with the idea of removing varnish and residues of Plextol B500 at the same time. Best results were achieved with acetone in the form of gel. Acetone gel (in Klucel G 3%) was applied with a bristle brush to one side of an Evolon tissue which was then laid on the painting’s surface and covered with Me‐ linex sheet in order to prevent fast evaporation of the solvent. The gel had to stay on top of the tissue for about a minute. During that time, the area was gently rubbed by finger. The solvent dispersed through the tissue and dissolved the varnish. After the removal of the compress, the surface was Fig. 197: Before removing the varnish
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