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Copper coating on silver in tumbler


#1

Hi folks,

I hope someone out there can give me a scientific reason why my
friend is having difficulty cleaning fine silver and sterling silver
in her tumbler. She used “super sheen” from Rio Grande and her first
batch of silver came out copper colored…thinking the cleaning
solution may be old (and it was) she tossed it and also replaced the
tumbler and the shot - - Second batch went in with a bit of dawn and
came out ok. A few weeks later she tossed another batch of newly made
fine silver bracelets in with some Sterling and when this batch came
out they were totally covered in copper AGAIN. Because the bracelets
were woven it was hard to clean out the nics and crannies of
discolored metal - finally someone told her to use the aluminum foil
and baking soda method, which worked. We are both at a loss as to why
this keeps happening?

Thank you,
Patricia White


#2

Sounds like some kind of a contamination. The only time I have had
silver turn copper is in my pickle pot if any kind of steel touches
that pickle it turns everything in it copper color that is why you
are supposed to use copper tongs to get your stuff out of the pickle
pot. However I use one of those mini crockpots from walmart for my
pickle pot & I have noticed that after a certain amount of time the
pickle solution eats away at the glaze of the ceramic pot and when it
interact with the silver sometimes that makes my silver copper color
too. The only thing I could figure out is that there is some
composition on the ceramic pot that must have something that
contaminates the pickle. Maybe there is something in your tumbler or
the type of water you are using, maybe where you are storing your
steel shot has something that is contaminating it. I know it isn’t
to terribly scientific but this could just be a clue.

Cecilia


#3

Patricia,

I’m curious, does your friend’s tumbler barrel happen to be made of
black rubber, as many are? If so, you will want to keep your
tumbling time with steel shot down to about 15 min. or less We have
found a longer tumbling time causes the black rubber to be abraded
off the barrel’s interior, and deposited onto your jewelry pieces,
causing a dark color. Is it possible this is what is happening?

…Just a guess

Jay Whaley


#4

Is it possible that some pickle found its way into the tumbler?

Chris


#5

I have a cement mixer type tumbler that I love. I use the green
barrel w/ steel shot. No problem w/ non-ferrous metal. My husband
uses the black barrel to tumble rocks w/ his rock tumbling media.
Not sure what it all is, but it is NOT steel shot. Plastic discs,
plus the abrasive he adds progressively from heavy to fine grit over
about 10 weeks! I love it so much that he never gets to use it any
more.

Happy New Year to all of you.

Kay Taylor
http://www.kaytaylor.ganoksin.com/blogs/


#6

As far as the pickle pot goes, the reason that things turn copper
colored if steal is introduced to a pickle pot is, while using the
copper tongs in the pickle solution, the solution becomes
super-saturated with copper ions suspended within the solution. When
steel touches the solution it cause a mild chemical/electric
current, causing the ion particals to bond to anything in the pot.
Here is a remedy if that happens: Mix 2 equal parts of Hydrogen
peroxide AND Sparex in a clean glass jar, then add 1 part water. Soak
the items in this solution for approx. 30 mins and check to see if
the copper color has come off. It should have but if it hasn’t soak a
bit longer. As far as the tumbler, It could be caused thermally. I’ve
had S.S. objects turn copper colored in my ultrasonic if it’s been in
too long. The steel shot could be causing enough friction to increase
the temp and cause this. I’ve seen my magnetic tumble get so hot I
can’t hardly touch it! This solution may help to get that discoloring
of the things from the tumbler also.

Good Luck! Steve Owner, Arista Designs


#7

I was interested in the comment about using a black rubber barrel
for more than 15 minutes. I have a Rio double tumbler with the black
rubber barrels. I commonly run it for 30 minutes or more, sometimes
as much as two hours, and so far - keeping my fingers crossed - have
not had a problem. I know people who run them overnight, but I have
not tried that!

I use the stainless steel shot from Rio, and Simple Green as my
liquid.

I am very careful about contamination. I was also interested in the
post mentioning the cheap slow cooker pickle pots breaking down;
that is what I use, and mine is about 5-8 years old right now… so
far no problem, but I’ll keep my eyes opened now that this has been
mentioned.

Beth Wicker
Three Cats and a Dog Design Studio
http://www.bethwicker.com


http://bethwicker.ganoksin.com/blogs/


#8

my experience with the cheap slow cooker is that they are all
different some do it & some don’t. I am sure it has to do with what
ever the ceramic pot is made from. I also don’t remember it
happening with the pots I had 10 years ago. You probably just lucked
out.

Cecilia


#9

Beth, depends on what you use for your pickle solution. Since I am
using household cooking vinegar, no problem.

John
John Atwell Rasmussen, Ph.D.
Geologist and Gemologist
http://rasmussengems.ganoksin.com/blogs/


#10

Hi,

I may have missed some things here, but I wanted to clarify
something. Any ‘pickle’ solution is acidic. It becomes heavy with
copper (even when the particles are not viewable with the naked eye).
Steel dumped in the solution causes the copper particles to adhere to
the metal in the pot much like what happens in plating processes. I
do not remember the nature of the process, but can go through my
notes to explain more.

I use ordinary vinegar as a pickle as well, and have had a situation
where the copper plated some silver and sterling I had in it because
I grabbed the wrong tongs (steel, not the copper ones). The variables
appear to be the amount of copper in the metals or in the liquid from
previous pieces, the amount and length of time steel is in contact
with the solution, and heat.

I don’t know anything about the liquid used by the original poster,
though it might contain some sort of pickle-ing agent. If there is
steel shot, sterling silver (not argentium) or copper, and an agent
such as vinegar (or other chemicals…not noticed with lemon juice),
there is a possibility of plating (we’ve planned to and have managed
to use this when we’ve soldered copper (using sterling solder) to
plate the copper over the solder seam. (to do that we waited until
the pickle needed to be changed, after a lot of sterling and copper
pieces had been in the pickle so that the liquid was closer to
saturated, then did it, as the process isn’t always as successful
when little copper has been dissolved in the solution.

Anyone know what is in the product by Rio Grande?

Kim


#11

I avoid getting any pickle into my tumbler by dipping everything
that comes out of my pickle pot into a solution of baking soda and
water to neutralize the pickle. I then rinse the piece thoroughly
under running water.

Where I have to be extra cautious is when I want to tumble my hand
made silver beads which have been in my pickle. Before tumbling
these, I soak them for a long time, in a solution of baking powder
and water, stirring frequently to make sure that any trapped air will
be forced out and the solution can get into the beads.

Alma Rands


#12
Anyone know what is in the product by Rio Grande? 

if you look up any manufacturers MSDS it will reveal the product’s
ingredients…

rer


#13

I never knew that you could pickle with vinegar & I have been doing
this for over 25 years. I guess you always learn something new no
matter how old a dog you are. Do you use straight vinegar or do you
dilute it with water?

Cecilia


#14

I already said all of this before and here is the solution, again. :

As far as the pickle pot goes, the reason that things turn copper
colored if steal is introduced to a pickle pot is, while using the
copper tongs in the pickle solution, the solution becomes
super-saturated with copper ions suspended within the solution. When
steel touches the solution it cause a mild chemical/electric current,
causing the ion particals to bond to anything in the pot. Here is a
remedy if that happens:

Mix 2 equal parts of Hydrogen peroxide AND Sparex in a clean glass
jar, then add 1 part water.

Soak the items in this solution for approx. 30 mins and check to see
if the copper color has come off. It should have but if it hasn’t
soak a bit longer. As far as the tumbler, It could be caused
thermally. I’ve had S.S. objects turn copper colored in my
ultrasonic if it’s been in too long. The steel shot could be causing
enough friction to increase the temp and cause this. I’ve seen my
magnetic tumble get so hot I can’t hardly touch it! This solution may
help to get that discoloring of the things from the tumbler also.

Good Luck!
Steve Owner, Arista Designs


#15

Hi Kim

Anyone know what is in the product by Rio Grande? 

You can find the ingredients of many of our products on their MSDS
Sheets. which can be found on our website. Just look for the tab
that says MSDS and type in our product number. This is a free
download and available 24 hours 7 days a week.

I hope this is of some help.

Mark Nelson
Rio Grande Tech Support
1-800-545-6566
www.riogrande.com


#16
I never knew that you could pickle with vinegar 

I like citric acid instead. Works great, and the studio doesn’t
smell like salad.

Noel


#17
I already said all of this before and here is the solution, again.
: As far as the pickle pot goes, the reason that things turn copper
colored if steal is introduced to a pickle pot is, while using the
copper tongs in the pickle solution, the solution becomes
super-saturated with copper ions suspended within the solution. 

OK, you said it before and I let it pass, but… You could use
bamboo tongs and the same thing would happen. The copper is from the
sterling or other alloys you put in the pickle-- what pickle does is
dissolve (mainly) copper. Your solution is close, though. Equal parts
pickle and peroxide (the kind you can buy in the drugstore), hot,
will fix the copper blush in seconds to a minute or two at most.
Stand and watch it-- if you go off and leave it, it will get etched.

Noel


#18
I've had S.S. objects turn copper colored in my ultrasonic if it's
been in too long. The steel shot could be causing enough friction to
increase the temp and cause this. I've seen my magnetic tumble get
so hot I can't hardly touch it! This solution may help to get that
discoloring of the things from the tumbler also. 

It is not heat it is still a electrolytic reaction. If anything
breaches the chromium oxide on the stainless the iron will be
exposed and you will end up with the plating of the copper out on the
silver or gold.

James Binnion
James Binnion Metal Arts


#19
Where I have to be extra cautious is when I want to tumble my hand
made silver beads which have been in my pickle. Before tumbling
these, I soak them for a long time, in a solution of baking powder
and water, stirring frequently to make sure that any trapped air
will be forced out and the solution can get into the beads.

For my hollow silver beads, after taking them out of the pickle, I
use disposable hypodermic needles (the type used by diabetics) to
inject baking soda solution into the hollow bead, and then inject a
couple of times with clear water. Never have any problems. If you
are not putting them in a tumbler thereafter, then place them to dry
on sawdust or a gentle warming with a hair dryer to assure they are
dry internally.

K


#20
You could use bamboo tongs and the same thing would happen. The
copper is from the sterling or other alloys you put in the pickle--
what pickle does is dissolve (mainly) copper. Your solution is
close, though. Equal parts pickle and peroxide (the kind you can
buy in the drugstore), hot, will fix the copper blush in seconds to
a minute or two at most. Stand and watch it-- if you go off and
leave it, it will get etched. 

Wrong. I’ve left the items in for hours before and… NO ETCHING,
EVER, in 25 yrs! You must also mix the 1 part water. I don’t ever
use the same pot for Sterling as I do Gold. There is a product call
Black Magic Pickle that I put my Sterling in and it works great! You
can also use it for gold and chains and Steel tongs. When soldering
chains, don’t put them in regular pickle because the clasps have
steel springs in them and will contaminate your pickle. Use the Black
Magic Pickle instead.

But you can use plastic or wooden tongs, of course. My solution idea
was for those who have a problem already.