Etching sterling silver - options for resist?

I’ve etched copper and brass before, using ferrichlorid and
sodiumpersulfate, and with these chemicals, I’ve used waterproof
markers, nailpolish and packageing tape as a resist. Now I’m about to
start experimenting with etching sterling silver, and I’m concerned
about the resists. I’ve ordered PnP-sheets, and if I understand
correctly, they should be fine, as should be packageing tape, right?
But what if I want to try to achieve a more organic look, would
markers or nailpolish work, or will they just wear out?

For the actual etching process, I have both 38% nitric acid, and
some ferric nitrate available, and I’m planning to try both - here in
Finland it’s unbelieveably hard to find a supplier for ferric
nitrate, and it was actually easier to find nitric acid.

I would appreciate any tips and hints on etching silver, too, since
this is my first time doing it. With nitric acid, I should probably
work outside, but how about ferric nitrate, I’ve seen a video on
Youtube where they etch silver indoors, but I don’t really have a
well ventilated area for that - will the fumes be awful?

Thanks for all the help!

Leena Pentti

For more organic resist - you can use asphaltum - the stuff you use
in your pitch bowl for chase and reposse.(however you spell it) You
can paint it on in random shapes or cover the piece and scratch thru
it.

Pay serious attention to the nitric acid - it is dangerous. Cover
your hands, face, eyes, arms and more. read and believe concentration
levels and how you dilute it further. High concentrations are hard on
the resist.

Judy Hoch

I also like asphaltum for a resist, especially if you are using an
intense mordant like nitric acid, or want a deep etch. It is used by
printmakers to etch their printing plates, so an art supply store
may have it. It works especially well in designs with scratched fine
lines. Invest in a good scribe, as it really sticks to the metal.
You can play around with stencils, or free-hand brushing too.

Asphaltum is a thick tar-like liquid, so you may want to carefully
dilute it a bit with naphtha (lighter fluid) and stir well. Use only
natural bristle brushes, not synthetics. I use inexpensive ‘chip
brushes’, available at hardware stores. A flat edge brush is best
for an even coat. A thick coat isn’t necessary. Let it dry until
hard. Only use metal or glass containers, as naphtha can melt some
plastics (been there, done that!). Use the naphtha on a rag to remove
it from the metal & for clean-up. You may need to use a toothbrush to
remove it from the etched lines. Use rubber or nitrile gloves & work
in a well ventilated area.

Don’t try substituting turpentine, acetone etc. for the naphtha.
Speaking from experience - they won’t work!

Happy etching!
Kim

Liquid electrical tape works well for me as a resist while
electrically etching SS in Ospho. It’s a lot like rubber cement
which I hear also works.

js

An aside to asphaltum – While in school many years ago, a friend of
mine would walk down a country blacktop road picking up pieces of the
asphalt that had flaked off the edges, He would then dissolve these
in gasoline stolen from his father’s truck, and filter out the sand
and other aggregate. When the gas evaporated, he was left with a
usable pitch for his pitch bowl and as a resist!

The very best, fast drying, resist for etching any metal is ETCHING
RESIST from Rio Grande.

Mary Ann Scherr