THE EFFECTS OF SELECTED SOLVENTS AND SOAPS ON A SIMULATED CANVAS PAINTING

AbstractA selection of solvents and reagents including soap gels was used to remove varnish from a prepared surface, comprising a paint layer and three varnish layers. Cleaning reagents were applied with a swab in a manner similar to that used by paintings conservators. Surfaces were examined before and after cleaning using scanning electron microscopy (SEM) and gas chromatography coupled with mass spectrometry (GC-MS). Solvents either swelled all three varnish layers rapidly or were not effective. Soap gel formulations worked more slowly on the varnish film without apparent swelling. Undercutting of the upper varnish layer was observed after cleaning using deoxycholic (DCA) and abietic (ABA) soap formulations, which were not specific to the uppermost layer. Gel mixtures based on anthracene-9-carboxylic acid (A9C) and 9-f1uorenone-4-carboxylic acid (9FOC) soaps were tried. The rate of action of the gelled soaps was influenced by alkalinity and the inclusion of solvent in the formulation. Residues of deoxy...