Signed, Sealed, and Delivered!
I recently completed and delivered two 24 x 30 inch copper bas-relief horse heads for a commission. This was a great challenge for me!


I can tell you that I spent a whole lot more time agonizing over these than I did actually hammering on them.
Keeping scale and function in mind, I deliberately kept them much simpler than my smaller work, with the emphasis on the lines of the drawing rather than on the surface detailing.
I did a brush and ink sketch, that was only line for the design. I scanned the design into the computer, sized it up to the right size and had it printed (facing opposite directions) full size at Kinkos. I transferred the design to the back of the copper sheets with lightly punched dots. (For a small piece I'd put those dots on the front, but not for a big piece.)
I started off by working them over sandbags, from the back side, with a variety of hammers. I worked a few areas with my pneumatic chisel (and bits modified for chasing). I annealed the sheets one time and then went to the refining. I did most of the refining from the front, and just a little from the back. I couldn't figure out how to do it without pitch, so I set up a wood block with pitch on it. I did the refining over pitch in sections.

You can see the wood block with pitch in this picture, waiting on top of the anvil. I filled up the section to be worked with pitch and slowly melted it with a very very bushy flame. When it was melted enough, I plopped the wood on it and weighted it with a sandbag until the pitch firmed up enough to move the whole thing.
I didn't want to set up a huge pickle bath, so I scoured the surface with an improvised scotchbrite buff

then patinated it with Midas red to black patina solution (from riogrande.)
I burnished back the highlights with handheld 3M Scotchbrite pads and sealed the surfaces with a low gloss tung oil varnish.
For you metalsmiths, yes I do love the 3M Scotchbrite and unitized wheel products for finishing. I buy them from industrial suppliers. I always wear a respirator when I use the products. I'm not so crazy about the FX wheels or radial discs, but I prefer a more distressed surface, even on jewelry.