Training course and workshop, Zagreb, Croatian Conservation Institute, 24th-29th October and 7th-11th November 2011
A cycle of training workshops for conservators-restorers titled ”Materials and Methods for the Cleaning of Paintings and Polychrome Sculptures” was organized by the Croatian Conservation Institute and supported by the British foundation the Headley Trust.
This specialist course was held by restorers and science experts specializing in restoration research and development of new techniques and products, most familiar with substances used by restorers and their working conditions, and also familiar with solvents which would be innocuous for restorers’ health while at the same time non-destructive for artworks. The seminar was designed as a professional training course mostly targeting the Institute's staff, with a larger number of attendants at lectures and a limited number of participants for the workshop.
The course’s aim was to train restorers in using solvents which are less harmful to their health, since standard chemicals are often toxic or even carcinogenous.
The first session lasted from 24th to 29th October 2011, with instructors from the Italian institute Opificio delle Pietre Dure in Florence. During the first three days Carlo Galliano Lalli, deputy head of the Scientific Laboratory of the Opificio delle Pietre Dure, presented a theoretical overview of the subject, introducing participants to the chemistry of solvents, discussing methods for the application of liquid chemical substances and providing an overview of non-aqueous methods of cleaning paintings, followed by aqueous methods of cleaning paintings, thickeners and carriers and combined methods of cleaning for paintings and wooden polychrome sculptures.
In the following three days, Oriana Sartiani, a restorer for easel painting at the Opificio delle Pietre Dure, demonstrated the application of new methods for the removal of impurities: non-aqueous methods, including solubility testing, neutral and low-toxicity solvents, dipolar aprotic solvents, gelled solvents, the removal and rinsing of various systems, the aqueous methods, tensoactive substances, emulsions with organic solvents, artificial saliva, resin and enzyme soaps, enzymes and buffer solutions, chelates and solid gels.
The second part of the course took place from 7th to 11th November 2011, again in the restoration workshop of the Croatian Conservation Institute. The instructor was the Italian expert Paolo Cremonesi, a conservator-chemist and one of the CESMAR7 group founding members.
Topics discussed during the seminar included main groups of organic solvents, their physicochemical and toxicological properties, the method of interpreting and anticipating the strength of neutral, dipolar, aprotic and ionizing solvents, the structure, classification and mode of action of hydrolytic enzymes, amylases and proteases, gelling agents such as Wolbers' solvent-surfactant gels and the interactions of solvents and bases with paint media.
The course was in Italian with consecutive interpretation into Croatian.
It was attended by 30 staff members of the Croatian Conservation Institute from the Department for Wooden Polychrome Sculpture, Department for Easel Painting, Workshop for Paper and Leather, Natural Science Laboratory and Branch Departments.