Investigation on a low environmental impact solvent mixture applied to a wooden painted slab

Cleaning is one of the most complex and delicate step in a restoration project, often due to the manufacturing techniques of the artifacts and their advanced state of decay. Eco-friendly solvents can permit to execute the cleaning operations with a reduced health impact for the restorers and for the environment. In this work, the performance of the 1,3- dioxolane/methylal (DIOX-MET) solvent mixture is evaluated over a wooden painted slab that had been covered with a thin layer of a protective varnish, probably during a previous conservation work performed in the Sixties. Removal of this varnish has been considered on behalf of its yellowing degradation process, which caused chromatic changes over the pictorial layer. The study was performed by comparing DIOX-MET performance to that of a traditional solvent mixture. The effectiveness of the cleaning process was followed in situ by using a portable FT-IR total reflectance spectrometer.