3D scanning and printing as conversation tools: an innovative treatment of a vandalized bronze statue, The Thinker by Rodin

This contribution discusses the innovative treatment of a severely vandalized bronze sculpture, The Thinker by Auguste Rodin, from the Singer Museum in Laren, The Netherlands. Additional aspects of this controversial treatment such as decision making and documentation are also discussed.

In 2007 the sculpture was stolen from the sculpture garden of the Singer Museum together with six other bronzes of which only The Thinker was retrieved. The thieves attempted to cut this Rodin bronze into pieces in order to sell it for its scrap value. As a result the bronze had several saw cuts, a distorted left upper arm and the right lower leg was missing. The museum approached the University of Amsterdam to research possible treatment methods.

After much consideration, the museum opted for a novel approach involving 3D scanning and 3D printing. This paper gives a step-by-step account of the practical work undertaken to restore the sculpture and focuses on the laser scanning and printing techniques and their use as conservation tools. The treatment included the use of 3D scanning of the damaged bronze as well as the original plaster model. By digitally superimposing the scans it was possible to create exact replicas of the missing areas of the sculpture. These replicas or fills for the saw cuts were printed using the stereo lithography process in a UV-laser light curable photopolymeric acrylic resin. These were subsequently used as models for cast epoxy resin fills that exactly fitted the sculpture. For the missing lower leg, a 3D print was made in a different acrylate: one that could be burnt out during lost wax casting. The new lower leg was then cast in bronze. All epoxy resin fills and the bronze replacement leg were attached to the sculpture in a reversible manner and retouched to near invisibility.