Confronto di metodi di descialbo con diverse sorgenti laser

The main aim of this work is to present the results of an experimentation carried out by a restoration graduation thesis, at Brera Academy Fine Arts in Milan. This thesis had the purpose of verifying the possibility of performing a descialbo operation with different sources laser on plaster artifacts. Plaster model samples were designed and built with the traditional molding technique. On their surfaces, was applied a thin layer of shellac and, then, three different types of scialbo were laid out. The laser ablation tests with the two different sources - neodymium source and holmium source - were performed using different operating ways (dry and wet) in order to identify the appropriate fluence parameters for removing the scialbo layer. The effects of irradiation and the different levels of cleaning were evaluated with the aid of colorimetric analysis and with the observation of cross-sections by Optical Microscopy