Experimenting with a blue/green patina

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.

cupric nitrate

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:

ring

….and here’s the ring after painting and heating it several times:

ring
ring

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!

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