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Pickle and polishing problems


#1

Hi all,

I am just an amateur working out of the garage on weekends. I have a
few questions I was hoping you could help with. Since this all applies
to one pair of “simple” earrings, I will tell the story that way.

I had decided to make these simple sterling earrings, sort of sail
shaped, with cutouts and three 18K gold balls placed strategically on
the sail. I soldered the earwire to the point of one of the sails. The
earrings are to be slightly bowed backwards, suggesting a full sail,
if you get what I mean.

I cut out everything and prepolished up to about 600 grit sand paper,
then punched little divits for the gold balls to sit in, then soldered
on the ear wires, hammered the wind into the sail, then soldered on
the gold balls. Everything was fine til I put them in the pickle for
the last time.

I fished them out and ewwwwwwwww what is this horrid gray stain? I
rinsed them in baking soda and water and then had to scrub off the
hideous gray stuff with a brass brush. There goes my "prepolishing!"
Anyone know what the gray stuff is? It is the usual Sparex #2, in a
canning jar set into an old crock pot filled with water - on “low.” It
is a pretty well-used batch of pickle - is it bad? I even tried to
leach out some of the copper with a piece of brass and binding wire.
This did not help at all.

As for polishing, I wanted shiny surfaces… instead I have a
scratched ugly silver base with gold balls on it- how do I polish it?
Alternately I wouldn’t mind a nice matte surface to contrast with the
gold balls, but how do I make that with no lines without a bead
blaster? I am never satified with the finish. If I use my foredom
tool, even a super slow speeds, it ends up leaving little bumps that
scream “overpolishing!” Worse I end up flattening my perfect little
gold balls. What are your suggestions?

So much for a simple weekend project! Thanks for your help.

Mary Barker
Member of Technical Staff
HPEFCU
@mary_barker
TN or 650-857-7372


#2
It is a pretty well-used batch of pickle - is it bad? I even tried
to leach out some of the copper with a piece of brass and binding
wire.

Hi Mary,

You could have contaminated your pickle with iron from the binding
wire. The iron went into solution then when a nice piece of silver
came along it precipitated on it. If not consider that if there is a
large amount of copper ions in solution then they too might also
precipitate.

Sailors worry about this only in reverse (electrolysis).

A question in general to you all. Are “formally” trained metalsmiths
and jewellers given exposure to a formal coarse in chemistry and
physics at the college level? Why do I ask, because they are working
with elements all the time.

For very different reasons I had the opportunity to take first year
chemistry and physics, a long time ago and both have served me
well all these years. I still have a CRC handbook on Chemistry and
Physics and recommend to all they should they find one, buy it. It’s
encyclopaedic.


#3

One possibility is that your pickle is old enough that the can it is
in has rusted. Iron gets into the pickle and deposits out on the
piece. If that’s the case, just toss the pickel and get new stuff.
But I don’t know how to save the piece. When it happened to me, I was
lucky enough to be making a spoon, and I could just buff til it was all
gone.


#4

Sounds like the gray “stain” is firescale…(the bane of my
existence)! There are plenty of previous threads here on Orchid that
can go over the ins and outs of firescale… As for polishing for a
high shine, I use tripoli as a pre-polish then rouge for a final
polish, this after I have used sand paper starting at 200 working my
way up to 600. If you don’t want to put that much work into it and
would like a matte finish, use steel wool in a circular motion. This
will give you a matte finish. But any deep lines (or scratches) must
still be removed or they will show thru the steel wool finish. Hope
this helps!

Laney


Laney Clark Kinetic Jewelry Designs


#5

Dear Mary: Others may disagree but it sounds like firescale to me.
This topic was covered a few months ago and I urge you to refer to the
archives on the subject if others come to the same conclusion in their
advice to you. As to how to get the matte surface, Rio Grande has
some 3M wheels for the flex shaft (and big ones for the regular
polishing machines) that yield a wonderful satin look. The coarse
version for the flex shaft is 338-125, and there are medium and fine
ones as well. Sometimes I use the coarse one to sand the piece and
remove the firescale when I have been too heavy on the torch. Hope this
helps.

Shael
dakotahdog@msn.com


#6

Is your grey stain fire scale? Do you know what that is? Did you
coat your silver with boric to protect the metal?


#7

Ok here is my 2 cents… You’re not going to want to put binding
wire in your pickle. It’s going to contaminate it! When your pickle
turns blueish from use, or when contaminated with iron it must be
changed, you don’t want to damage things you put in the pickle…
for example, if the pickle is contaminated you will get copper on
your silver, it will turn pink, and you then have a lot of clean up
to do… thanks AW


#8
Iron gets into the pickle and deposits out on the piece. If that's
the case, just toss the pickel and get new stuff. But I don't know
how to save the piece.  

G’day; the answer’s simple. Throw out the used pickle and refill the
pot. Then heat your copper plated item until it goes black - the
thin copper film will have been oxidised to copper oxide from oxygen
in the atmosphere. No need to heat really strongly. When it has
cooled put it in the fresh pickle and leave for 10 minutes or so. Have
a nice beer or a sherry. Copper gone! Neutralise, wash and dry it,
And that’s it!

John Burgess; @John_Burgess2 of Mapua Nelson NZ


#9

By al means ,you do not just toss it down the drain!!! Neutralize it
first with washing soda and then it go’s down the drain.please,think
about our planet.Two kilo’s of that sodium cost maybe 1 “ONE” dollar,
and last for a very long time.Howmuch do you pay for One liter of
drinking water ???

Regards Pedro
Palonso@t-online.de


#10
You're not going to want to put binding wire in your pickle.   

2 + 2 = 4 cents why not use stainless wire Rio sells it that way you
can pickle before removing wire just in case you have to re-due

BillyBob
Made By Hand
Leesburg, Florida


#11
   if the pickle is contaminated you will get copper on your
silver, it will turn pink, and you then have a lot of clean up to
do 

Easiest way to take care of that problem is to make a new batch of
pickle and add some hydrogen peroxide. That will remove the copper
coating on the silver. Louise @lgillin1


#12

Dip out some of the pickle, add peroxide to it and immerse the piece
in this solution to remove the copper flashing.