Adhesive Meshes. Implementation and bonding properties in paintings conservation with focus on textile supports.

Abstract: A painting’s canvas that lost its strength due to degradation processes or damage might need a support with an auxiliary textile. Adhesive meshes provide a new bonding system for the laminar reinforcement of fragile canvas paintings. These microstructured, self-supporting and flexible nets are produced of a series of pure and well-established conservation adhesives: methyl cellulose in two viscosity grades, sturgeon glue and butyl methacrylate. Their application involves positioning the mesh in dry state, activation with controlled supply of moisture or solvents, and pressure to generate the adhesion. Unlike the common application of these adhesives in solution at low concentration, it is not liquefied during activation, but swollen and thus discretely remains in the joint without penetrating the textile. Consequently, a regular, permeable adhesive pattern and an exceptionally precise application is enabled as well as an increased reversibility. The striking advantage towards commercial lining glues is the use of single adhesives of a more constant composition, proven ageing behaviour and the application without heat or harmful solvents. Due to their different activation and bonding specifications, the choice of the adhesive is adaptable to a painting's condition and requirements. By varying the activation parameters, adhesion can be manipulated reaching from a slight tack up to a remarkably high strength that is sufficient to perform a strip lining.
The PhD project is embedded in an ongoing research project aiming to develop a standard for the production of adhesive meshes, carried out as cooperation between the Bern University of Applied Sciences (Switzerland), the company APM Technica AG (Switzerland) and the Dresden University of Fine Arts (Germany). The main objective of the subsequent PhD assignment is to define the application spectrum of adhesive meshes for the conservation of canvas paintings as well as to establish reference values as guideline for their implementation in practice. The focus is on canvas bonding, especially for evaluating the method for re-adhering detached areas of historic linings or for strip lining. The investigation of suitable activation strategies and an in-depth examination of canvas bonds carried out with adhesive meshes will be pursued, including adhesive strength, penetration of adhesives into the canvas and long-term behaviour. Case studies will encompass the experiments to evaluate the transfer of the method into practice.