Glass artefacts conservation: finding materials and methods for glass vessels’ reconstruction

This paper will address art glass conservation, focusing on the search for the best products and methods to be employed in glass vessels’ reconstruction, including case studies. In 2000, an archaeological site was found in Padua (Northern Italy) where the Santa Chiara in Cella Nova Monastery once stood (1325–1797), and thousands of Renaissance artefacts came to light. Thanks to a collaboration between the Soprintendenza Archeologia, Belle Arti e Paesaggio per l’Area Metropolitana di Venezia e le Province di Belluno, Padova e Treviso and the University of Bologna, a huge conservative project started. The conservative intervention on the precious glass vessels became the starting point of a research on the best products to be employed in their reconstruction. More than for other materials, an analytical approach is necessary while dealing with glass: commonly employed techniques need to be adapted to suit features of every object, and new ones must be examined. Furthermore, testing and comparing well known products to most recent ones or to ones developed for other purposes is essential. In this study, an acrylic resin and four epoxy resins were tested, the latter both pure and added with three different colouring agents. Accelerated ageing tests were run to find out the products most resistant to discolouration through time. The results were compared with practical application’s tests to select the best combination of products and techniques. Finally, the intervention on two glass vessels, coming from Santa Chiara Monastery, is presented briefly.