Well today was a day I've looked forward to for a very long time. It was a day to color (Patina) the life size cowboy piece, "Working for the Brand". Bronze is any of a broad range of copper alloys, usually with tin as the main additive, but sometimes with other elements such as phosphorus, manganese, aluminium, or silicon. It was particularly significant in antiquity, giving its name to the Bronze Age. "Bronze," in turn, is perhaps ultimately taken from the Persian word "berenj," meaning "Brass".
Heat and chemicals are used to color bronze. Once I went over the bronze and had a couple of areas smoothed or corrected, it was time to color the bronze using differing acids and chemicals. First the bronze is bathed in a potash solution that turns the metal black. Then the patina lady, Diana, using a Brillo, rubs off the black where the bronze's color will require more bronze showing. Like the face. The scarf around his neck is left black.
The video gives you an idea of the sounds in the foundry, as Diana heats up the bronze and using a spray gun, she applies acid to turn the color of the bronze.
Here are photo's showing how the hat is turning more of a brown color as Diana torches the piece and sprays on the acid.