-2 parts white vinegar
-1 1/2 parts non-detergent ammonia
-1/2 part non-iodized salt.
Clean your copper/remove any lacquer with steel wool and rinse thoroughly with water to remove any residue.
Mix the above ingredients together in a misting bottle.
Lightly, but thoroughly, spray the mixture onto the copper and allow it to dry 1 hour. Reapply to any areas that you may have missed. Allow to sit overnight to develop. Brush a bit to remove loose particles before sealing with clear spray lacquer. If you want a bit of the bright copper to show through, sand raised areas before sealing.
Adjusting the salt ratio in the mixture will affect the shade of the patina. More salt=more boldly green. Less salt= more greyish.
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