The consolidation of silicone rubber and its challenges

Satenik Aeschi, Leonie Jansen, Gerda Kaltenbruner, Martina Pfenninger Lepage, Valentina Pintus

Institute of Conservation-Restoration, Modern and Contemporary Art, Academy of Fine Arts, Vienna, Austria

This contribution is part of a wider research project performed at the Institute of Conservation-Restoration, Academy of Fine Arts, Vienna, which includes two other studies on phenolic foams.1 This paper summarises the research carried out on an unusual material assembly consisting of silicone rubber and floral foam (also known as open cell phenolic foam). These two materials are the main constituents of an artwork titled “Modell: Zwischendeck” (1995) by the German artist Dorothee Golz.

The polygonal object, with three-dimensional mushroom-like elements, shows mainly a green-coloured mossy-like surface. The white silicone rubber being poured into a dead-mould casting made of green floral foam blocks, led to the silicon surface being almost entirely covered by a thin layer of this foam. The silicon rubber penetrated into the gaps between the foam blocks and formed mushroom-like elements. The back of the object was stabilized with glass fibre reinforced Epoxy resin and a hanging device.

The artist interview provided information about the manufacturing process and the artist’s intent. Extensive investigations, test series and material analysis (FTIR-ATR) helped to better comprehend the complex surface texture and properties of this composite material.

Mechanical damages, material inherent changes and the excess weight of the mushroom-like elements have led to deformations and tears in the silicone rubber. The work could thus no longer be mounted on the wall and shown to the public.
The presentation will focus on the performed research into the artistic materials and the stabilization of the fragile elements. Furthermore research was carried out to find an adhesive suitable for silicon rubber to ensure the long-term preservation and stability of this artwork.

Consolidating tears in silicone rubber is challenging, since there are only a few methods to adhere silicone rubber due to its anti-adhesive and rubber-elastic characteristics. In addition the properties and appearance of the phenolic foam surface has to be taken into account while choosing an adhesive. In the framework of this work different methods to adhere silicon rubber were discussed and a number of adhesives were tested on two types of silicone rubbers samples.
Simultaneously, research is focusing on the alteration of phenolic foam during the aging process to better understand the varying degrees of color changes in this material.
Furthermore, proper binding media and application methods were evaluted for the consolidation of detached foam fragments.

The challenges and the outcome of the test series will be discussed in detail hereby.