Copper is a fun metal to work with. It’s soft after heating, but can be hardened to be pretty resilient. I love hearing the sound difference between hitting soft and hard copper. Its natural color has a wonderful warmth, but the variety of finishes that come from it are amazing.
There are many ways to give copper a great patina and here I’ll show the most common: heat and sulfur. Sulfur gives copper a beautiful black finish that is especially great for bringing out detail. This is done by polishing or brushing off the surface darkness, leaving all details and crevices in the metal dark for contrast.
Here I’m starting with some leftover scale cutouts from a large chainmaille collar project I made for Metal Arts / Jewelry I. Each of the scale pieces was sawed by hand from a large sheet of copper.
The chainmaille is all stainless steel, and most of the scales are nickel silver with copper to accent. Every scale got two holes drilled in, then the copper was given a texture and patina, and all were slightly domed in a dapping block.
Here is a perfect example of why it’s always good to keep hammer faces polished and nice. That line in every hammer blow is a little scratch on my hammer. It’s hard to notice until the light hits it and I had already done most of the hammering so I kept going.
Time for some fire! Heat can give copper a huge range of beautiful colors for a finish. I’m only showing one look here, but heat finishing can vary greatly.
When heated to red-hot and let cool, a clean piece of copper will get a sweet matte red coating.
After pickling (a bath in mild acid) to clean the metal, I scrub it with a brass brush.
The brass brush gives a bright look to the copper. So clean!
Time to make a sulfur solution. The can is full of varying sized yellow mineral chunks.
When heated, the sulfur makes quick work of the aging process! Even cold it doesn’t take more than a few minutes.
The top half was scrubbed with a green scour pad and the bottom polished with a cotton wheel and mild compound. In the scale collar I used the scoured style, my favorite since it gives a rougher antique quality.
I really have fun playing with patinas and making samples. By the way, it is the copper in sterling silver that causes it to tarnish over time. This sulfur will do the same to sterling silver and I use it all the time to do so. Pure (i.e. fine) silver will not tarnish like sterling, but its softness means it needs things like copper alloyed with it for strength.
If you have any questions about the process feel free to ask!