Statuary bronze is a term given to a range of copper alloys featuring a rich umber patina. The base material for this patina process can be performed on any copper alloy, including bronze, brass, and raw copper sheet. Copper alloys are transformational, meaning that they will continue to change over time.

Many successful patinas on brass and bronze alloys use heated copper nitrate solutions or pastes made from copper sulfate and copper acetate. The processes should be performed by professionals experienced with working with chemicals and corrosives. Because many of the treatments involve heating the metal fabrication with a torch, large objects or objects with flat, thin planes are difficult to color successfully. Cast forms and smaller fabricated shapes will color adequately if cleaning is performed correctly.

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The Ohio Holocaust Memorial is clad in prepatinated bronze

Samples should be required for approval prior to ordering any part or sheet. The architect, hardware supplier, and fabricator of the light fixture and door panel must see the same resulting finish and agree to the acceptable variations prior to having all the parts arrive at the project.

MAINTENANCE OF BRONZE FABRICATIONS

Bronze and other copper alloys should be periodically maintained. Lacquers should be removed when they show signs of yellowing and cracking. Waiting for the copper alloys to develop the blotching stains will necessitate major, often expensive, cleaning and polishing. Relacquering should be performed when the surfaces have been properly neutralized of all cleaning and polishing agents.

A periodic maintenance program should be established in order to sustain the surface appearance of quality copper alloy work. The quality of clear coating applied over a copper alloy surface will dictate the frequency of necessary maintenance. Exterior lacquer coatings should be maintained at least once every five years.

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Photo of Bowdoin College Walker Art Center, clad in prepatinated bronze

Bronze statues are not often exposed to handling or severe environments. They usually receive a conversion coating, followed by multiple coats of lacquers. These surfaces should be expected to last as long as 10 years before removal, cleaning, and repolishing.

Metals are very good at inhibiting biological infiltration. Bronze, as well as other copper alloys work especially well in preventing mold and fungus from growing. Copper is used as a surfacing material on boat hulls to resist the fouling of the surface by barnacles and algae. The alloys of copper, including brass, bronze, and others each provide this capability.

To learn more about designing a finish with statuary bronze, contact a member of the Zahner sales team.

Works featuring Statuary Bronze