SINERGIA TRA DETERMINAZIONI ANALITICHE E DOCUMENTAZIONE STORICA NEL RESTAURO DELLA CATTEDRALE DI SAN DONATO, MONDOVÌ (CUNEO, ITALIA)

: In 2012-2013 some important restoration works have been conducted in San Donato Cathedral in Mondovì (Northern Italy, Cuneo Province, the last project of the famous architect Francesco Gallo (1672-1750). The edification started in 1744, but the dedication was achieved only in 1763. The building is an impressive brick-made church composed by a central nave and two aisles, with the considerable dimensions of 56 meters length and 24 meters width. A baroque style with some neoclassical additions is the main theme of this church. After the edification the internal decoration of the church was very simple, probably in a plain style of uniform bluish or grayish tinge. In the XIX century some new works of transformation took place, and developed in two separated periods. The first period at the end of the thirties of the 19th century, involved only the presbyterian area, and these works were directed by the first designer and art director for the Royal Palaces of king Carlo Alberto, Pelagio Pelagi from Bologna. Only twenty years later the cathedral was the object of some new transformations, to give the Cathedral the modern dignity of a church-cathedral including also a wide line of wall paintings. Therefore, around the 1850, new decorations were made, committing some of the most important sacred art painters of that period: Paolo Emilio Morgari, Luigi Hartmann, Andrea Vinaj, Isacco Gioacchino Levi and Francesco Gonin. One of the main goals of the Restoration Team was to obtain scientific information about the materials used by those artists and others decorators, through analytical investigations such as SEM-EDS microscopy and other techniques. The historical background immediately appeared important for the knowledge of the different phases of construction and decoration. Ancient documentation treasured in the archives of the church, in the city library and offices and in the Bishop Curia and archives, demonstrates to be very useful, and proven to be one of the primary source of information. Our working team took advantage of this big number of documents (old letters, contracts and communications) to have a clear overview of the situation. This material, concerning the agreement between the Customer (the Mondovì Curia) and the construction team, between the Bishop and the different painters, but also between different artists (some of them already in contact and collaborating), includes also other precious information. Main themes are the construction techniques and the decoration choices, following the buildings evolution not only from an artistic point of view, but also from a technical point of view (for example the preferences for different materials use, the application of specific painting techniques due to different artists and also some legal controversies about gold or silver decoration on stucco, or about delay in the delivery of paintings and frescoes). The documentation addressed us on the research of some specific building materials, and on some painting techniques involving particular pigments and binders. An accurate investigation was made on the stratigraphy of plasters and mortars, confirming an agreement between the edification phases of the church and the distribution of the strata in the samples. All the information found in the ancient letters about painters’ own techniques, seem to be confirmed by the analysis of the pigments and binders used in different areas. The scientific investigation involved optical microscopy, fluorescence analysis, image analysis, scanning electron microscopy, electron microprobe analysis and mapping, FT-IR spectroscopy, microRaman spectroscopy, X-Ray powder diffraction and microchemical essays. All these techniques allow us to achieve a deep knowledge about materials used by painters and decorators, plasters and mortars and the current state of conservation of all these hand-made artworks. Last but not least, the knowledge of historical materials and state of conservation, obtained through ancient writings and modern analytical techniques, allowed the restoration team to work in the best way to assure a complete and deep restoration of the paints, stuccoes and artworks inside the Cathedral, as well as to choose, between different products, those that can guarantee less damage and higher duration of restoration works.