Here's my experience so far.....
The copper metal clay is similar to the bronze in workability.....which makes sense since bronze is an alloy of copper and tin. To start I always take a hunk of it with a little spritz of water and knead it in saran wrap. Let it sit for about 10 minutes and it's ready to go.
To make slip I use olive oil for all three types of clay. I know some people use lavender oil for bronze but I don't have any in the house and I do have olive oil. It works well and the slip seems to last a while when I keep it in an air tight container. Some people recommend making new slip each time you work with the bronze and I would assume the same with copper. I don't, but you decide. I've had some of the faux rivets in the bronze come off after firing. Maybe it was due to old slip or maybe it was due to not using enough slip. I suppose I should try using new slip every time to see if I continue having this problem :)) DUH.
If I'm in a hurry I dry the wet clay on a cup warmer. If you don't want it to warp, put it on the cup warmer and press down on it very lightly with something flat. Flip it over and do the same on the other side....like searing a piece of meat. This will keep the warping down to a minimum. Unless you want your piece to warp. I like the warp factor....at least in bronze and copper. It gives it an aged, beat-up look.
You fire the copper as you do the bronze...buried in carbon in a stainless steel container. On Bill's recommendation I have been firing in the coconut shell based carbon. I use a full ramp up to 1650 and held for 3.5 hours. It comes out of the kiln a matt pink/peach color.....like a very new penny. I have been using a 3-sided nail buffer to shine up the high spots on the bronze and copper. I know some people prefer to throw the pieces in a tumbler for a high shine....just depends on what look you want.
Since the coconut shell based carbon doesn't give colors, I use a torch to heat patina the copper. You can get varying colors by heating the copper and then pulling it away from the flame and exposing it to the air. It's really cool to pull the copper away from the flame and see color flash across the surface.
That's about it for now. I'll be working with the copper some more tomorrow. I've got some ideas for some new shapes based on old tools. Everything old is new again.