Long-term exposure of unprotected copper alloy sculpture in an outdoor environment has resulted in the alteration of the original surface of the sculpture. The conservation treatment of outdoor copper alloy sculpture has included the repatination of degraded surfaces, either locally (spot) or overall. The chemical repatination process is an irreversible treatment that has catalyzed conservators and has fueled discussion within the profession.
This paper will present the preliminary investigation and field-testing of a reversible toning system that consists of a binder and pigment system followed by warm wax treatment. The toning system provides a diverse and reversible treatment to adjust the appearance of the degraded copper alloy surface of the sculpture. The conservator can adjust and control the toning to meet a variety of aesthetic needs. An example of the implementation of the toning system will be presented as well as the interaction with the curator, initial findings in the application, removal and adjustment of the system.