The bronze sprues and vents are removed and the casting remains. If more than one piece is involved in the sculpture, the parts are welded together and the resulting seams removed with careful grinding and sanding. After a final sandblasting or glass beading, the bronze is ready for the final finish, a patina. Patinas are created by applying liquid chemicals to the surface of the bronze after it is heated with a blow torch. Under heat these chemicals react with the copper content of the bronze alloy to give a controlled oxidation.
Colors can vary according to the intensity of the heat and the chemicals used.
Usually many coats are applied until the desired color is obtained. This final step is the application of several coats of wax or sealer to enrich the color and protect the bronze.