Copper patina processes (2024)

I've been obsessing over this lately, and plan on running some experiments to acieve different colored patinas like copper oxide 1 (red), and 2 (black), as well as copper carbonate (green), and copper sulphate (blue).

Here are some processes I have gathered so far.

This one is theoretical:

Create simple copper carbonate by spraying on a rust solutionuntil thick and green and then heat (boil?) to acheive oxide 1 (red), and heat higher for oxide 2 (black).

This is based on known experiments based on Benedict's test:

Mix 16 oz hydrogen peroxide and 12 oz. of white venager and a teaspoon of table salt. Spray it on and let it dry in cycles to create copper carbonate (the green patina).

Heat the copper carbonate to create copper oxide 2.

Heat some hydrochloric acid (slightly) and add the black oxide to create copper sulfate (the blue stuff).

Make a mixture of sodium carbonate, and sodium citrate, in distilled water with plenty of sugar. Add the part and bring the solution to a boil until the copper sulfate turns to copper oxide I (red).

Here's another method for the red copper oxide 1

(A)Cupric sulfate 25gm

Distilled water 1L

(B)Amonium chloride .5gm

Boil emersion A 15mins.
Boil emersion A+B 10 mins.
Boil part in cupric sulfate solution until red color well developed
Remove to hot water while amonium chloride is added to the cupric solution then emerse 10 minutes.
Rinse, dry, and finish.

Edited February 10, 2018 by Zeb Camper
added process