THE PATINA:
Below are a few pictures of the Oehmcke Commission - "Candice & Jackie" getting a traditional patina (consisting of blacks & browns). A patina takes the bronze piece which is a gold color, and changes the color by use of chemicals that are applied when the piece is cold or hot. If the piece does not get a patina it will change colors by exposure to the outdoors and air similar to copper. For “hot patinas”, a propane torch is used to heat the metal surface to the appropriate temperature to achieve the desired effect. Different chemicals (e.g. nitrates of copper, silver, iron, etc.) and application techniques (e.g. brushing, squirting, spraying, etc.) can be used to achieve a broad range of colors and effects.
The sculpture is hosed down with water and then the Liver Sulfur (base patina) is sprayed on which makes it a dark black and seeps into the crevices.
Here the piece is rubbed down with a scotchbrite pad so the original light bronze color is seen and the Liver remains for contrast. The piece begins to dry and is ready for the torch!
The sculpture is getting spun on a sculpture stand as Mike, at the Bronze Works Foundry, takes a torch working on heat consistency throughout the whole piece (220 degrees).
Once it has reached the right temperature the piece is sprayed with Ferric Nitrate and then once the desired color is reached a wax is applied to the surface while it is hot.
Once the piece is cooled a harder wax is applied and buffed.
Finished!!