Done a search of the archives but couldn’t see the answer to this
problem. I accidently place several bracelet blanks that I was
annealing into a sparex pickle, and guess what! They ended up copper
plated. So I have a couple of questions.
1; Can I easily remove the plating without resorting to abrasives (
they have been textured)? I was thinking of Hydrocloric acid?
2; As I work with both copper, brass/bronze and silver, is there a
pickle that won’t copper plate. I have tried using seperate
containers but eventually the brass one will copper plate.
I use Sparex and my pieces never copper plate. Of course I never
introduce steel into the solution. Don’t blame your pickle for
actions of your jeweler.
Yep - there’s an easy way to do it. Place the items that are plated
into a bath of 50% pickle and 50% Hydrogen Peroxide (the regular
drug-store strength). Doesn’t need to be heated. It will react with
the copper plating and turn it a brownish color that easily
brass-brushes off without messing up surface textures.
Any acid bath will plate. The key is to understanding WHY and
avoiding it. What’s happening is that in the presence of a ferrous
metal (steel, iron), the free copper ions in the used pickle bond
with the copper in the sterling or brass alloy. The more “blue” your
pickle appears, the more copper is in it.
Keeping your pickle fresh will help reduce plating. Being rigorous
about using ONLY copper tongs and plastic utensils in or near the
pickle will also help. But it seems that every once in a while, some
little something (a hinge pin in a purchased clasp, for example) will
sneak in. In those cases, no matter how clean and fresh your pickle
is, some plating may occur (from copper leached from old piping in
your plumbing, from surface areas of the piece, your copper tongs,
etc.).
If your bracelet blanks were the only “contaminant” in the pickle
(i.e., you didn’t use steel tweezers to put them in and nothing else
was in there), then I’d be a bit suspect as to what the blanks are
actually made of. Do you know that they are really sterling? Do they
have findings that could be problematic?
Of course, there is also the case when you WANT to plate something.
For example, when you’ve used silver solder to construct a copper
piece and want to copper plate the silver solder seams. In this case,
you can deliberately control this reaction, use well-saturated old
pickle and a pair of old cross-lock steel tweezers, and leave it in
the solution for quite a while. You’ll get a nice plating action from
that.
This happens because there was likely a bit of iron or steel in the
pickle at the same time. It can be as small as the spring from a tiny
clasp. I believe even the nickel underplate from a rhodiumed silver
piece will start the reaction.
Short of acids try polishing with a soft white brush on the
flexshaft. The bristles go around detail rather than ‘smear’ it.
Ferric chloride (Radio Shack?? for etching copper circuit boards)
will etch copper but not silver. Hydrochloric won’t touch copper,
nitric will but it’ll eat your silver and brass, but not quite as
fast as the copper ;-( You might try annealing to burn off the copper
flash (no flux or other coating) and re-pickle.
Steel contacting anything in any pickle will plate out the
copper, basic electro motive chemistry not a question of which acid
is employed. Just keep steel out of the pickle
Brass will look like is is being copper plated by most any
pickle… in reality it is the depletion of zinc from the surface.
There are usually no magic fixes, learn the processes and
sometimes you can even exploit what normally is a bad side effect.
I learned this from my professor in Art school who got it from
Charles Lewton Brain: It works like magic- Simply heat up some FRESH
Hyrdrogen Peroxide in the microwave in a dish of some sort for about
15 or 20 seconds. The next step varies.If you had just discovered
you did this,leave the parts in the pickle for now. (The amount of
water,sparex on them as yopu remove them is usually enough
fluid))Then when you are ready with the H2O2 take the parts right
from the warm pickle into the warm peroxide. Instantly the piece
will bubble.If it doesnt,I just use a small plastic spoon or lid or
whatever you can find to get a little of your pickle liquid into the
H2O2-slowly dribble until it starts to bubble and fizz. Good
ventilation is always nice,even just a couple open windows. Keep an
eye on the progress,it only takes seconds.Ive gone too long and the
copper plating turns a little black-so watch out. I have done this
for years,shown many people and everyone thinks its magic. Never
polish off copper plating again! Also works for 10k,14k and 18k.
Note: Dont dump this mixture in your pickle either,things will become
black.Also make sure to neutralize the mixture with baking soda
before dumping the spent stuff down the drain.
Dip it into nitric acid for a few seconds - until it stops
fizzing. When you take it out the copper is gone. Be careful with
nitric acid; even the fumes are dangerous. Read the MSDS.
Copper that is dissolved in pickle will be plated onto immersed
silver or gold if there is any iron present. Iron binding wire, or
steel tweezers can trigger the process.
Chris, I think I have said this so many times I feel like a shill
for Reactive Metals, But Bill S. did a paper on this problem. I have
tried it and it works like a charm, just add some 3% hydrogen
peroxide to some fresh Sparex type pickle (the amount does not seem
to be too critical, I use about a 25 percent H202). Use warm. The
peroxide oxidizes the copper and the acid dissolves that oxide.
Viola - no more copper flash.
We have run into the same problem on some silver pieces. We mostly
work with gold items and my assumption is that copper is being
leached out of the yellow alloyed gold. One solution has been to
manually polish the copper away, but that is laborious and doesn’t
work very well on intricate pieces or chains. However, we’ve also
found that a quick dip in Tarn-X alleviates the problem in most
cases.
I’m surprised how many folks don’t know the “magic fix” for
accidental copper plating! It was posted yesterday, but just to
make sure everybody got it (since the plating problem does happen
occasionally)-- equal parts pickle and drug store peroxide. This is
sometimes called “bright dip”, though it will etch slightly and
leave your silver dullish.
I have always used it hot-- watch it closely, it’s fast. It also
works to remove the “blush” that often happens on soldered brass.
That is reputed to be a zinc-depleted surface, not actually copper
plating, but it amounts to the same thing, and bright dip works.
The solution doesn’t keep-- mix just what you need, use it,
neutralize it, throw it away. With any luck, you won’t need it again
for a year anyway!
Hi Folks, thanks for all the replies on and offsite.
I’m pretty sure its plated and not depleted because I actually
didn’t put the bracelets in a pickle, rather I put them into my
rinse bucket. Unfortually the little pickle that got into the rinse
bucket was enough to plate (man it doesn’t take much).
I always use plastic or non ferric tongs but still have this
problem, and I can’t figure a solution for pickling brass pieces. I
might try cooling in water and then clean the firescale with
hydrocloric acid, it has worked well for me in the past. The
suggestion that the contamination could be from nickel was something
I didn’t realize. It will be something that I will be aware of in
the future.
I will also try the hydrogen peroxide solution and see how well it
works. Also last night I played with the plated pieces by lightly
sanding the tops of the texture surfaces and then tried blueing the
copper just to see what it would look like. First results are quite
promising, the plate wasn’t thick enough to get a real nice blue but
it was enough to darken the copper to make the texture really pop
out.
So this now leads to another question. I like using dixgold
(commercial bronze I believe) as its a good material and finishes
well. So how would I get rid of firescale without plating or
depleting?
I use Sparex and my pieces never copper plate. Of course I never
introduce steel into the solution. Don't blame your pickle for
actions of your jeweler.
For those of us who do it for a living, no matter how careful I am in
inspecting jewelry I repair, there are times that something will
unexpectedly cause copper plating, usually charm bracelets. Actually.
rhodium plated charms seem to cause copper plating also. If it
crosses my mind that copper plating might occur, I use citric acid to
pickle.
If I space out and end up a with copper plated piece, the hydrogen
peroxide and sparex dip saves me from having to physically remove it
by laborious polishing.
even though i can’t stand Krohn industries products personally, they
do sell sparex #1 for ferrous metals…i’m surprised more people
aren’t aware of that !
If it crosses my mind that copper plating might occur, I use
citric acid to pickle.
I use citric acid exclusively, and though I haven’t had a problem
with accidental plating, I have also had no problem plating
intentionally when I want to, as for certain fusing situations, so I
don’t think using citric will be any real help.
Just a historical note, I wrote the H2O2 Pickle paper 1979-80.
Glenice Mathews another graduate student at KU had a paper on an
industrial process using H2O2. I reverse engineered down to the
drugstore variety H2O2 and Sparex. An original copy of my paper is in
the archives somewhere. It is has been passed on many times. I am
always gratified to see the pop up and in use. I still
sell it for 50c, although the paper may be a little yellowed. Bill
Working in a studio with students things get accidentally copper
plated all the time. Start a new (ideally warm) bath of pickle,
enough to cover your piece(s), then add a few tablespoons of Hydrogen
Peroxide, which you may have around the house already. If the plating
doesn’t disappear add a little more h.p. Brass is the worse for
copper plating. It’s tough to get around once a pickle solution
reaches a certain copper rich state.
I was taught once to place a ball of wadded up aluminum foil in the
pickle to remove copper. I have used this method for years with as
far as I can tell no bad affects. The foil will almost instantly
plate with copper sometimes I will do it twice it seems to collect a
fairly large amount of copper. You have to watch, if you leave it
too long the foil will start to desolve. I think 10 or 15 minutes is
sufficient.