Patination of copper and its alloys

patyna miedzPatination of copper and its alloys. The easiest, but requiring quite a long time, the method consists in placing objects wetted with acetic acid in an atmosphere of carbon dioxide and water vapor.
At the bottom of the tub or plate, a layer of wet sawdust or wet sand should be poured on a wire rack, hang the items to be dyed. Place a steamer under or next to them, filled to 1/3 by volume of sodium carbonate. Pour over the contents of the evaporator with acetic acid (ok. 50 cm3 of 10% vinegar and immediately cover it with a jar of the right size. Co 2…3 days to change the contents of the evaporator, adding a new batch of vinegar each time. Repeat the treatment at least three times. After rinsing the items with water, dry them in a stream of air.
• Zanurzać przedmioty w jednym z podanych niżej roztworów, at room temperature, containing in 1000 cm3 of water:
a) 330 g of copper nitrate i 330 g of zinc chloride,
b) 1000 g of copper nitrate i 350 g of calcium chloride,
c) 80 g of copper sulfate i 20 g of ammonium chloride,
d) 500 cm3 of concentrated ammonia water, 3 g ammonium chloride i 3 g of copper sulfate, e) 30 g of copper nitrate i 10 g of ammonium chloride – this solution should be rubbed on the metal surface with a cotton wool or cloth. When the desired color is achieved, rinse the items with water and dry.