19th & 20th Century Bronze Sculptures

Patination of Bronze

The final process in the creation of a bronze is the patina or finish that is applied to the surface of the bronze.  The surface patina that you see on a bronze sculpture is an applied finish and is in actuality only a forced tarnishing of the metal. This is done by heating the sculpture with a torch and applying different acids and other chemicals to the hot surface. The resulting color depends on which chemicals are applied.  The application of different chemicals in sequence will result in a multi layered effect.  The order in which the chemicals are applied can effect the color of the sculpture. Gilt bronze patina required the use of an arsenic based solution being applied to the hot metal. This resulted in shortening the life of many foundry workers and artists.  Many of the techniques for applying patina to bronze were closely guarded secrets and the ability to create them died with the artist or foundry patinator. The patina on a bronze is extremely thin and fragile.  Normal every day dusting over centuries can remove this thin layer of coloration. Finding a bronze with its original patina in perfect condition after more than 100 years is like finding a piece of period furniture in its original finish. The value of a bronze sculpture is effected greatly by the condition of its original patina.