Bronze Cast Sculpture in Varied Patinas

Bronze has been the most often used material for casting sculpture. This is because of the bronze property which could flow and fill all cavity of the mold and therefore reproduce artist’s original work. The so called bronze is actually not pure copper, instead it’s a alloy with a combination of copper and other elements. Silicone, tin and zinc are common element used for forming alloy.

Another benefit of using bronze for casting sculpture is its ability to make varied patina. Bronze can react with other chemical easily to represent varies color. The commonly used technique for patina is torching approach and immersion approach, depending on the size of the sculpture.

The Torching approach is suitable for middle or large scale sculpture.

• The first step is to clean the bronze body completely, remove any grease. This is the key step which would make a difference on the final effect. The grease remains would prevent the bronze reacting with the chemicals and leave inconsistent color on sculpture.
•  Then brush and polish the bronze surface. This purpose of this step is not only clean those tiny in and out of the sculpture but also make chemical work with bronze more easily.
• After that, heat the bronze with torch up, spraying chemical solution onto the bronze. The most used chemical are cupric sulphate, ammonia compounds, etc. The craftsman torch the bronze surface sprayed with chemical solution and make sure the chemical reaction happens. Usually the process would be done a couple of times.
•  There are multiple options for patina. Basically, there are four major color group:Brown; red, green, black. There are quite a few gradual alternatives and combinations of these colors.
• After reaching the desired patina, the craftsman would brush a thin lay of wax or apply coating onto the bronze sculpture. This could protect the bronze patina last longer.

Below are a few of bronze sculptures we patina.

If you have any technical question about patina, feel free to contact us.