Expanded polystyrene is a material widely used by artists and designers that we can find nowadays worldwide in contemporary art and design museum collections. Jean Dubuffet used it for making prototypes whereas Tara Donovan, Gyan Panchal, Ronan and Erwan Bouroullec or Paul Cocksedge use it for certain of their finished artworks. Sometimes, this material is not even visible, as it is painted or covered by a resin layer as in Niki de St Phalle, Claes Oldenburg or Paul Ollagnon ’s artefacts. Nevertheless, this material hasn’t been widely studied in the conservation field.
In this cooperation project with Die Neue Sammlung – The International Design Museum Munich, several conservation issues related to this material were investigated. The initial point of this project started with the lamp Styrene designed by Paul Cocksedge in 2002-2003. The design lamp is made out of hundreds of heat-shrinked extruded expanded polystyrene coffee cups.
As two parts of the object were broken and one part was missing, this project focused mainly on finding adhesives and gap fillings suitable for the design object long-term preservation and sustainability.
The protocol includes reproducing the designer’s manufacturing process, the solvent and bonding tests made on both heated and unheated expanded polystyrene, the development of a suitable gap filling method by the combination of an expanded polystyrene inlay and a dry adhesive film, and the conservation treatment itself.
Concerning the bonding tests, a selection of adhesives has been made according to the moral code of conservation including a well long-term stability and reversibility if possible. As the adhesive shouldn’t affect the artwork original material, a wide range of different adhesives such as protein and gluten adhesive, ether cellulose, acrylate solution and dispersion, PVAc and PVB dispersions and epoxies was selected. Then, parameters such as the bonding strength, colour, gloss, physical behavior, ease of manipulation entered in account. As a result, on expanded polystyrene, starch wheat glue could be used for a weak bonding, sturgeon glue for a medium bonding and Mowital B60 HH for a strong bonding. For heated expanded polystyrene, the adhesive selected for the restoration of the lamp was starch wheat glue.
Concerning the gap filling tests, several dry films based on starch wheat glue and ether cellulose or acrylic dispersion such as Lascaux 498HV, mixed with fillers such as micro balloons or expanded polystyrene powder gave promising results.
This study is a research made in the conservation workshop of the museum.The purpose of this study is to provide more informations about expanded polystyrene material and show the state of an experiment within a workshop, with our own tools and through simple mounting tests systems. It has to be seen as a starting point for a further research on this topic in a scientific setting.