Thozet Medals, 1866-7

Designed by artist Charles Summers, manufactured by W. Calvert. Collection of CQ University, Faculty of Sciences, Engineering and Health.

Description

These bronze medals, sealed in a domed glass covered, circular cedar frame, were awarded to A. Thozet in 1866-7. The copper medals were structurally sound. The frame of one medal was broken and had a past repair, which was poorly aligned. The glass on one of the frames was broken.

The surface of the copper medals was very discoloured (dark brown and black) due to tarnishing of the metal, with some corrosion present. There were areas where finger marks had etched into the copper medals.

Treatment

The medals were dry surface cleaned to remove all superficial grime. The old repair was reversed and the break realigned and adhered with conservation-grade adhesive. The old polish residue was removed, and the copper alloy medals were polished.
The copper alloy surface was degreased and a micro-crystalline wax coating applied to form a thin film of protection on the surface from moisture and oxygen. The broken glass was replaced and the frames appropriately reassembled.

Treatment stages

Figure 1

Medal 1 - Before treatment, corrosion of copper alloy evident.

Figure 2

Medal 2 - Before treatment, corrosion of copper alloy evident.

Figure 3

Misaligned join in outer wooden frame, before treatment.

Figure 4

Medal 1 - After treatment.

Figure 5

Medal 2 - After treatment.