After fabricating the kalanchoe ring, I wanted to experiment with a blue/green patina, like verdigris. But I didn’t happen to have this chemical and decided to try a couple other alternatives.
I was too impatient to wait for the ammonia/vinegar solution to re-act and thought I’d make some cupric nitrate. I read here that you can add 1 part nitric acid to 2 parts water in a glass jar. Also add copper scraps and wait until copper dissolves and the mixture turns dark blue.
I left the jar outside and waited for a few hours. When I went back to check what was going on, I was surprised to see that the copper had vanished, or dissolved to be more precise.
I added a few more scraps to see if the acid could still dissolve more copper.
Fortunately it couldn’t and this meant that it had turned into cupric nitrate.
I painted the copper flower with the solution and heated it gently with the torch to dry.
This is what it looked like after the first application:
….and here’s the ring after painting and heating it several times:
Sadly, this color doesn’t seem likely to stay for long, it wears off easily. I sprayed it with a matte varnish in an attempt to seal it but that seemed to weaken its intensity considerably.
The ring will probably end up having a dark black patina but as long as this color is still on it’s nice to look at, don’t you think?
Thanks for reading!