Making It Stick: Challenges with the Recoating of Miró’s Outdoor Bronze Sculpture Entitled Personnage

Jessica Chasen, Arlen Heginbotham, Herant Khanjian, and Julie Wolfe

Abstract

The J. Paul Getty Museum has carried out a technical study and treatment of Joan Miró’s outdoor bronze sculpture entitled Personnage (designed 1976, cast 1985). The sculpture was brought into the conservation lab to address issues with surface efflorescence of core material and to replace aged protective coatings. Examination of the Getty sculpture, thought to be cast at Fonderia Bonvicini in Verona, revealed significant visual differences from other casts of the artist’s work and the complicated edition history was explored through dialogues with the foundry, archival research, and x-radiography. The article presents quantitative analysis of the bronze alloys with XRF and contributes reference data that can be used for comparison with other Miró bronzes. The early stages of the treatment involved the removal of aged coatings using dry ice blasting and solvent cleaning, with the aid of FTIR analysis to identify the materials removed layer by layer. A range of maintenance waxes, a previously undocumented partial Incralac coating, and underlying earlier coatings were characterized, along with their solubilities, in the course of the treatment. The porosity of the casting allowed migration of salts from the remaining core material and localized corrosion. An acrylic lacquer system called Permalac was initially chosen for recoating due to its effectiveness in other outdoor sculpture treatments as well as its selection of tinted lacquers ideal for reversibly correcting visually distracting areas of damage. Issues with adhesion of the new coating led to the development of a more extensive methodology to evaluate the adhesion and quality of a test coating using ASTM standards that were modified for use on outdoor sculpture. The process included testing of several different coating mixtures and application protocols on copper coupons and the sculpture itself. Both the analysis and the treatment reinforced the need for constant adaptation, with several cycles of scientific analysis and treatment testing informing coating removal and yielding incremental improvements in the performance and appearance of the surface coating.

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2019 | Uncasville | Volume 26