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Old pickle - [Digest]


#1

G’day Sandra; When sterling is heated copper in the alloy
becomes oxidises to copper oxide and copper sulphide. The
sulphate ION in the pickle (sparex is sodium hydrogen sulphate)
dissolves the copper compounds leaving a thin surface layer or pure
silver. The copper becomes copper sulphate, (and you’ll have
noticed that old pickle is pale blue) But if a piece of iron - no
matter how small - is introduced, a tiny electric current flows and
the silver becomes copper plated, but the film is generally very
thin. You can get rid of it easily by first making up some fresh
pickle in a clean jar, then heat the silver briefly to just below
soldering temperature, which will oxidise the thin copper film.
Put it in the clean, uncontaminated pickle and in a few minutes the
job will have regained it’s silvery-white look. Remove it from the
pickle with brass, copper, or preferably plastic forceps, wash it
thoroughly in sodium carbonate solution to neutralise the acid and
’Bob’s yr uncle!’ But don’t heat too strongly or for too
long, and you shouldn’t get the dreaded fire stain. Iron or
steel tools will always precipitate copper from a used pickle
solution. I made my forceps from a 3/4 inch strip of rigid plastic
(Perspex to us; Lucite to you folk) I’ve had 'em for years.From: AStick7910 AStick7910@aol.com

You must have picked your piece up with some steel tweezers- it
makes an electrical plating effect, and coats your piece with
copper from the pickle. You have to buff the copper off, or sand it
, or whatever. sometimes this can be useful, you might want to
copper plate something (like gold), so you could oxidize it with
liver of sulpher, which won’t normally color gold. then you buff
the copper off the high spots. anne

From: MetalWerks MetalWerks@aol.com

Sandra, Somehow you must have gotten a piece of iron or steel into
your pickle. When steel or iron is placed into your picke solution
it changed the pickling solution into a plating solution and what
you did when you placed your piece of silver into your pickle was
to plate it with the copper that is slowly removed each time you
pickle a silver piece. The only way to get rid of the copper is to
buff it off or strip it off with a plating unit. Michael

From: Deewo Deewo@aol.com

The pickle was contaminated. I"ve seen it happen even to fresh
batches of pickle when some-one tossed in something that
interacted with the sparex,or used non-copper tongs, or left iron
binding wire on a piece. Step 1 is to get rid of the old stuff,
clean out the pot and mix a fresh batch. Sometimes re- pickling
will clean it up, but maybe someone else knows the magic answer
to clearing up the pink. Donna–on Long Island where the blossoms
are exploding

From: Ed Colbeth wander_r@rocketmail.com

Sandra, Your pickle turned into copper plating solution. If your
going to use sparex type pickle you have to change it when it
starts to change color or all of those little copper ions will
start to deposit themselves on your work. Just anneal the piece
and put it in some fresh, hot, pickle. I use nitric acid(10:1
water to acid)for my silver pickle it lasts a very long time.
Always add the acid into the water, otherwise it may
splatter…bad…!

Eddie

From: Brian Minnear MR@hagley.school.nz

I suggest that you may have had some iron deposits in your old
pickle. This happened to a student of mine when she immersed her
recently soldered stirling ring whilst it was still bound with
iron wire! Cheers from Christchurch N.Z. [ where the Autumn leaves
are just beginning to turn.]

From: Elizabeth Wilkinson wilkinso@chem.umn.edu

Hi, The piece turned pink because copper ions in the pickle plated
out onto the sterling piece. This usually happens when you put
the silver in and there is some iron comtaminant, like iron binding
wire, yellow ochre, or iron tweezers. The iron reduces the copper
ions which then plate out as copper metal, and some iron goes into
solution as iron ions. If your pickle is really green, maybe it is
loaded up with copper and you need a new batch. In any case, you
should be able to heat the piece with a torch until the copper
turns to black copper oxide, and then quench it in pickle and this
should get rid of the copper coating. Hope this helps. Cheers,
Elizabeth

From: onyx onyx@wac.com

Sandra, I believe what happened was that somehow iron got into the
pickle. Prehaps thru a small piece of binding wire,or maybe iron
oxide( no flow?), or steel tweezers? Once introduced to the acid
bath, the iron created an electrical charge, depositing a thin
copper coating on any metal in the bath at that time.The thickness
of the copper coating is dependant on the strength of the
solution.Heating the solution (or putting an electrical charge on
the silver) will increase the plating response. By the way for
safety’s sake, you should never boil sparex because dangerous fumes
will be generated. Sparex works best at about 180 degrees F.To
remove the plating, first try mixing a new batch of pickle.If that
dosen’t work you may have to polish the silver. If the silver is a
chain, best to use baking soda and a tooth brush or rub it in with
your fingers while you gently pull the chain thru the baking soda
in your fingers.(this is a much better experience than getting a
chain caught in the buffing wheel and losing a finger) good luck
and let me know how it works out. Don Wollwage in hot and sunny
Northern CA.

From: Tim Goodwin tmn8tr@earthlink.net

Sounds to me like you dipped your piece in pickle that was
contaminated. Aside from re-polishing the piece, the easyest thing
to do is get rid of that old pickle, and make a fresh batch, and
make it a little strong. Soak it in that for awhile while it’s hot.
You can also heat your piece a bit and quench in the hot (New)
pickle, this should bring the silver back pretty fast.

Tim

From: JVPCO JVPCO@aol.com

what you did is put a silver plated ring in pickel or a some
steele got in your pickel . i would make new pickel and clean
your pickel pot good !!!

From: “St. Eligius & Co.” eligiu@mole.slip.net

your pickle has been contaminated with steel/iron. in so doing it
has literally metamorphasized to a copper plating
solution.solution: repolish the whole piece and habitually make new
solutions. good luck. kim

From: Jewlr 1 Jewlr1@aol.com

You contaminated your pickle with steel, either with tweezers or a
piece of steel you thought was sterling. You should get rid of that
pickle and mix and new. Remember no steel in the pickle!

From: “Guy Audette” gaudette@videotron.ca

Hi ElegantBee (Abeille elegante),

Normaly, when it happen, it’s because you have put steel in the
bath. Maybe you have drop the silver in the bath with a steel
tweezer or you put the piece in acid with the iron wire (binding).
The fact is that there is a lot of copper in the old bath, it comes
from the sterling but also from the copper tongs you use to put
and take out the pieces, so, steel is charging the solution (acid
bath) with electricity and when you drop pieces in the bath it is
making the same phenomenon than electroplating, all the copper
stick to the piece. Bye!

Vincent Guy Audette
gaudette@videotron.ca
Quebec, Canada

From: Dauvit Alexander dauvit@clanjamfrie.demon.co.uk

Old pickle tends to be copper-saturated (from the copper content
of sterling) and if any iron gets into it, it will actively
copper-plate your sterling at any temperature. There are two
things I would suggest for removing this plating: 1) Use emery
paper when the surface is still wet or 2) Electro-strip it. If
the pinkish copper is really light, though, it will often wipe off
with your fingers.

Hope this helps.

Yours aye,
Dauvit Alexander,
Glasgow, Scotland.

From: solk1@juno.com (Sol Krichevsky)

Sandra…Not having been there I cant be sure what happened but
I’ll take what I think is a good guess. Any iron object placed
into a pickle solution will cause copper to plate out onto the
silver. If you were using iron or steel tongs to handle the hot
silver, the tongs may have entered the pickle solution unoticed. It
only takes a second for this to happen. The other possibility, not
markedly different, is that some small iron particles ( filings
perhaps ) are in your pickle solution. I’d just dump the pickle and
start over. I"ve been thru exactly this myself, and have watched
students do it regularly. Let me know what happens.

Sol K.

From: Marion Margoshes mbm@panix.com

Beautiful, springlike New York-the dogwood trees are really
magnificent! Sounds as if the pickle was contaminated by a previos
piece. Pickle and peroxide - half and half - should help.

From: “Arnold” arno000@ibm.net

Hello Sandra, If pickle is contaminated with steel, it will begin
to plate things with copper. This is a handy trick to know, but a
mess when you don’t want it to happen. The only way to stop it is
to get rid of the pickle and start fresh. A drill bit or a broken
saw blade could be the culprit. Tom


#2

Thank you , thank you everybody for such wonderful and helpful
responses. I tried re-placing it in new pickle, but not actually
quenching it-- and it didn’t work. Heating it worked a little. So
I will try some of the other suggestions and let you all know what
finally does the trick. Sandra