Etching bi-metal

I am looking for instructions to etch bi-metals. copper silver. I
would like the copper on the top surface, sterling silver on the
bottom. I will put a patterned resist on it, then will etch with
ferric chloride - all of the copper away, leaving st. silver
untouched. Specifically I needed to know if the silver and copper
are fused or if it can be soldered, and what metal thicknesses work
best. Anyone experimented with this?

I’ve experimented, soldered the thin copper to the sterling (nasty
surface to the silver after etching because of the solder. Then I
started fusing, better success but some air bubbles to work around. I
found it’s far better to buy the fused bimetal. Yes, you can solder
after etching. I hydraulic press and then solder. You have to solder
delicately, the copper is pretty thin (and I roll it in the mill, too
before pressing). I’ve even enameled on it. If you want to see what
one of my pieces looks like, contact me off-list.

Donna in VA

Copper/Sterling Bi-Metal can look like this:

Fold, engrave, etch and carve to reveal these contrasting surfaces
(1/8 copper by thickness). Combine with the other bimetals for great
effects. Melting point 1432 F(+/-20 ). Please order in one inch
increments. Minimum 1 x 1 inch. Maximum 3 x 12 inches.

From here:
http://www.reactivemetals.com/Pages/rmsbime.htm

Add some PNP Blue as a resist Can be from here:

At last an iron on mask that really works! Make printed designs for
anodizing and acid etching in minutes. Print your designs direct from
a laser printer or photo copier. PnP Blue has two layers of special
material. Your design is printed on the blue layer. When the image is
ironed on to the metal the blue transfers too. This adds an extra
thick coating of protection. Tests in our studio indicate that the
coating holds up well to 100 volts.

For workers in non-ferrous metals this is a resist made for you. It
works well in ferric chloride, ammonium persulfate and sodium
persulfate diluted to manufacturer’s specifications. A household
iron is all you need. After use the resist is easily removed with
lacquer thinner.

And you are in business.

Please excuse the blatant horn blowing.

Bill

Bill, Deborah & Michele
Reactive Metals Studio,
Inc928-634-3434, 800-876-3434, 928-634-6734fx