Choose what color finishing is best for the brass you want to dye -- for example a golden yellow, granulated green or a bright finish. Call the Occupational Safety and Health Act, OSHA, at (202) 693-1999; teletypewriter (TTY) number: (877) 889-5627 to inquire about getting a handling license, safety handling equipment and guidelines.
Purchase Hydrofluoric acid, Nitric acid, Muriatic acid, Sal ammoniac and distilled water from a hobby shop or call Sur-Fin Chemical Corporation at (213) 262-8108. Chemicals for mixing your own patinas; Bryant Laboratory (800) 367-3141 Supplier of Brass, Copper, sheet, plate, bar; Metal Supply Company Philadelphia, (800) 638-2521.
Clean the brass surface thoroughly from any metal pieces or grease by scrubbing with a scoring pad and powdered soap, then rinse it and leave to dry. Brush it using a fine wire brush to remove any traces of soap. Take a plastic container with lid and vanish the inner surfaces with sapolin.
Add carefully 1 1/2 pints of Muriatic acid to 5 pints of water in a large plastic container with a lid. Cover and slowly turn the container to swirl the liquid inside then let it settle. Add 1 pint of Nitric acid in small drops until its all finished then complete the mixture by adding 2 pints of hydrofluoric acid ensuring you do this at intervals.
Tie a length of copper wire to the brass as a handle and slowly lower it in the solution. Leave it there for about two hours then lift it up and let it drain all the solution completely for 90 seconds. Spray it with a solution of Sal ammoniac dissolved in water periodically for 12 days to achieve a green color, known as patina. Drip banana oil on it and polish the surface with a cotton cloth.