Hi folks. I have had quite a few requests for the ferric nitrate
Credit must be given to Anne Hollerbach for telling me about it in
the first place. I have fine tuned a few of the procedures.
My source for Ferric Nitrate is:
Bryant Laboratory Inc. 1101 Fifth St. Berkeley, CA 94710 800 367 3141 510 526 3141
Ferric Nitrate for Etching Silver
This protocol is for etching silver and to be used as a safer
alternative than nitric acid.
As with any procedure, please use gloves when handling and dispose of
properly. I use the Hazardous Waste Day in my local neighborhood. It
will keep well closed in a plastic container. You will get about 3
etches out of this. Be sure to wash your hands well afterwards.
Ferric Nitrate stains!
Best for small jewelry scale items.
Transfer your design onto the silver using the method of your
Back the metal with duct tape or some kind of resist.
Mix a batch of distilled water (heated to warm) in a 3 pts water
to 1 pt ferric nitrate. Use a small plastic container with a snap on
lid. You might want to adjust your ratio adding more ferric nitrate.
Find some styrofoam. The height must be at least 1/2 inch. Hot
glue the styrofoam plus a handle to the back of your piece.
Ferric nitrate unlike nitric acid, requires that the piece be turned
down with the image facing the bottom. As the etching proceeds, the
residue will fall to the bottom. The styrofoam acts as little pontoons
and floats the metal just below the surface.
Now for the part that makes this really work. Go to your local pet
supply company and get a cheap aquarium pump. These will cost about 8
dollars. Lay the small container on top of the pump and wrap the whole
thing in duct tape.
The vibrating action of the pump keeps the ferric nitrate moving and
the etch speeds up quite a bit. I use this for my ferric chloride
The aquarium pump is used to being plugged in and can be left for a
few hours. The etching takes about 2-3 hours. Depending on your
transfer medium, PnP Blue or the 3M PPM 2500 (my personal favorite),
you should get a good, clean etch.