Hello!
I’m doing mokume rings made of sterling and nickel silver. As
the color contrast is not very expressive and any patina wears
off quickly, I would like to acid etch them in order to give
these rings a little more structure. So my question is how to
etch the nickel silver? Which acids? Concentration?
Thanks,
Sabine
sabineas virtual gallery:
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Sabine,
Try some experimentation, as different acids will do different
things. I’d suggest making up a simple test plate with a number
of small pieces of your material to try with differing acids.
Nitric acid will definately attack both metals, but may do so at
different rates. Try a fairly dilute solution first, I’d guess.
Etching both metals like this would be to give a slight texture
to the silver parts, and a different texture perhaps, as well as
(hopefully) some definition of depth between the layers, to the
nickle silver.
Hydrochloric won’t actually etch the silver, but will turn it a
sort of smutty off white color (a layer of silver chloride forms,
which is insoluable, and stops further attack by the acid) The
nickle will be etched a bit. Again, I’d try it first with a
pretty dilute solution. Easier to add a bit of acid to increase
the concentration if it doesn’t seem to be doing enough.
Sulphuric will slightly attack sterling if it’s hot, but cold
more dilute solutions won’t touch it much. However, it will
easily attack the copper based nickle silver. This is my guess
for a bright sterling/deeply etched nickle sort of look. As
before, start with dilute solutions (I’d guess 5-10%) and try
it.
For a very slow steady etch on the nickle silver, give some
ferric chloride a try. I don’t know if it will actually work,
but it won’t touch sterling, and on copper it etches smoothly and
evenly. Since nickle silver is mostly copper, I’d expect it to
have some effect.
All the above is based only on general basic knowledge and what
I would expect to happen. I haven’t actually tried etching
nickle silver before. So this is a guess. But I hope it’s of
use.
Peter Rowe
Sabine -
Nickel silver is a copper alloy (percentage of copper:nickel is
not at my fingertips at the moment) and can be etched just like
copper or brass with ferric chloride. You can buy the liquid form
from Tandy/Radio shack; a pint costs about $3.50; or you can mix
your own from the ferric chloride salt available from a chemical
supply house such as Bryant Lab in Berkeley, CA. The salt will
cost you about $16 per pound. For years I used the salt, mixing
it in a ratio of about 12 oz per quart of water. This was the
formula I read in a jewelry book, and it seemed to give OK
results. I thought it would be much “stronger” (work better,
last longer, cheaper) than what Radio Shack sells already mixed.
About a year ago I ran out, and used some Radio Shack stuff in a
pinch, and got the same results for 20 percent of the cost and 1
percent of the hassle. So now I just buy the stuff already mixed.
Use full strength.
Just in case you’re not familiar with etching in general, ferric
chloride will hold up to a number of different resists:
asphaltum varnish, Sharpie markers, PnP blue paper, fingernail
polish, rosin, and printmaking grounds available at a place like
Daniel Smith. Immerse your piece with the area to be etched
upside down. This keeps the sediment from accumulating in your
etched areas. You will see some bite in about 30 minutes.
Depending on the strength of your resist, a very deep bite will
take up to 5 hours. Nickel silver takes a little longer to etch
than copper or brass. After etching and rinsing your object with
water, you must neutralize it in ammonia for at least 10 or 15
minutes.
BTW, you can get an especially beautiful gray green patina on
nickel silver by rinsing the ferric chloride off thoroughly in
water, but not neutralizing in ammonia. Instead, just dry your
piece and leave it overnight and the next day you will see your
greens. If you need to remove your resist with mineral spirits, a
soak in the spirits for awhile seems to enhance this patina and
sometimes will bring out some salmon pinks as well. You’ll need
to seal the surface with a lacquer or wax or the patinaed surface
may continue to develop. If you don’t want to do this because of
the silver, just rinse and scrub and rinse and scrub very very
thoroughly. Since you are putting the patina on the etched
surface, it shouldn’t wear off like it would on a smooth
surface.
Hope this helps with your questions.
Rene
Ca North coast
Nickel silver is a copper alloy (percentage of copper:nickel is
not at my fingertips at the moment) and can be etched just like
copper or brass with ferric chloride. You can buy the liquid form
from Tandy/Radio shack; a pint costs about $3.50;
A few years ago I did a lot of brass and copper etching with
FerricChloride. I found the best place to buy it was a real
electronics parts store. The price was about $10 US for a
gallon. Much cheaper than Radio Shack unless you just want to do
one or two pieces. Also, I found that it gives a better etch
when warm (about 80-90 deg F), The upside down method did not
produce an even etch. I left it right side up and would lift out
of the solution and tilt the piece every 5 or 10 min.
In a World Without Walls and Fences, Who Needs Windows and Gates?
Bobert
Carmel,CA
Peter, Please correct me if I’m wrong, but I have always thought
that “nickel silver” was just a marketing term for elemental
nickel. If so ,would it have any more than a small percentage of
copper? (if any) Would not the question then be “what mordant
works on nickel?” MTR
Pure Nickle is marketed as nickel… by itself… Nickle silver
is the name given to a nickle/copper/ zinc alloy, of which there
are several.
From Oppi Untract: Some nickel alloys:
Nickle silver= 65 Cu, 18 Ni, 17 Zn
German silver= 65 Cu, 23 Zn, 12 Ni
Monel= 67 Ni, 28 Cu, 5 Fe
Nichrome 80 Ni, 20 Cr
Hope this helps.
Peter Rowe
For a very slow steady etch on the nickle silver, give some ferric chloride a try. I don't know if it will actually work, but it won't touch sterling, and on copper it etches smoothly and evenly. Since nickle silver is mostly copper, I'd expect it to have some effect.
It works great! I’ve tried to etch my sterling and nickel silver
mokume rings in a solution of 20 g ferric chloride in 100 ml of
lukewarm water for a short time (about 10 minutes) and they came
out very nicely textured.
Sabine
sabineas virtual gallery
metal-design, jewelry & silverwork