Gah! Pickle Turned My Silver and Brass PINK…

Sample sterling chain, and the same chain with the dreaded copper flashing...

Sample sterling chain, and the same chain with the dreaded copper flashing…

Copper is awesome.  It carries electricity through our world, and it makes many things blue, like octopus blood and turquoise stones.  We’ve been making stuff out of copper for, oh, something like 10,000 years. Yep. Really.

No surprise that we magpie humans first used copper for jewelry (ooh, shiny, pretty!), and we are still using it, a lot of it, in making jewelry today. Even when metal isn’t copper colored, it can still be mostly copper, like brass, bronze, and nickel silver (which, confusingly, contains no silver).

Most of the time, copper is a tremendously pliant and forgiving player in the jewelry studio, but occasionally it “misbehaves” and ends up in places we don’t want it to be. Sometimes… we pull a piece of silver or brass out of the pickle, and it’s… gah! it’s PINK!! Do not despair, chemistry is the cause, and chemistry will come to the rescue!

So, the thing about copper flashing – the thin layer of copper on the surface of sterling silver or brass that pickling sometimes produces – is that it has two causes, and one solution (there’s a pun in “solution”… we’ll get to that shortly). The most common pickle is sodium bisulfate dissolved in water.  After you solder something, this handy acid cleans the piece by eating the crusty flux and oxides off the surface.

Sample sterling chain, and the same chain with the dreaded copper flashing...

Cause – temporary iron contamination

Cause # 1 – Iron in the Pickle:

In the case of sterling silver, copper flashing happens when iron is introduced into the pickle pot.  This causes the copper in the pickle to plate out of the solution onto whatever objects are steeping in the liquid. For this post, I wrapped the chain above in a bit of iron binding wire and a few seconds in the pickle produced this spectacular result.

CLASSIC JEWELRY MYTH: “Pickle that has been contaminated with iron/steel is ruined forever and must be thrown away.” FALSE!

FACT: This contamination is TEMPORARY. Simply remove the offending iron/steel tweezers, binding wire, etc. and the pickle will return to it’s former more benign state. The only time the pickle is ruined is if you cannot remove all the iron/steel (i.e. tiny particles of steel wool remain in the pot).  Even if the pickle has eaten through the enamel on a metal pickle pot, exposing the iron/steel underneath, you can transfer the pickle to a different pot and it will be fine. You’ll need a new pot, but not new pickle solution.

Lowther---copper-flashed-brass-sheet

Cause – zinc depletion from alloy

Cause # 2 – Zinc in the Alloy:

Copper flashing on brass happens not because copper is plating from the pickle onto the brass, but because the pickle is revealing the copper in the alloy.  Brass is actually composed mostly of copper.  The other main ingredient in the mix is zinc (a grey metal…go figure).  The pickle acid likes to pull the zinc off the brass surface, leaving the copper behind.  Sometimes the whole piece of brass will be completely pink, sometimes there will be just some areas that are pink and other areas will still be yellow brass (like the picture above).

SOLUTION – Etch the Copper Off with SUPER PICKLE:

In a small plastic container, mix equal parts of:

  • warm pickle solution (scoop a little bit out of your pickle pot*)
  • hydrogen peroxide (regular ol’ 3% stuff from the drug store)

I used about 1/8 cup of each.  A few tablespoons will do if that’s enough to cover your piece of metal. Don’t mix more than you need because the solution doesn’t keep.  It loses its efficacy within the hour.

Use PLASTIC tongs (or wood, or copper, NO iron or steel!) to drop your metal piece into the Super Pickle.

The results can be pretty dramatic…

Lowther---super-pickle-at-work-on-silver

The pictures above and below are greenish because the pickle solution is a greenish blue.  The bubbles – vigorously obscuring the view in the images above, and behaving more decorously in the images below – are indications that the Super Pickle is working, stripping the copper off the surface of the metal.

Remove your piece as soon as the copper is all gone.  Rinse it well.

Lowther---super-pickle-at-work-on-brass

Once the copper is gone from the surface of your piece, you will notice that the surface is also much less shiny and smooth than it was originally.  This is because the etching action of the Super Pickle has begun to bite into the metal under the copper flashing.  The longer the metal sits in the Super Pickle, the more the surface is etched, hence the instruction to remove the metal as soon as the Super Pickle’s work is done.

Lowther---silver-after-etching-with-super-pickle

Lowther---brass-etched-from-super-pickle

If you want the metal to be shiny again, you’ll need to polish it.

Bonus awesomeness?  After you are finished with your Super Pickle, pour it back into your pickle pot.  No muss. No waste.  The hydrogen peroxide breaks down very quickly into water and oxygen, so all you are putting back into your pickle pot is a bit of diluted pickle.  Since water evaporates from pickle pretty quickly when it’s warm, you have to add water to the pot every now and then anyway, so the spent Super Pickle helps keep the regular pickle solution at the right strength.

May the force of Super Pickle be with you,

Signature - Lowther

* For my regular pickle solution, I mix about 2oz (roughly 2 Tablespoons) of granular sodium bisulfate with about 1 quart (~1 liter) of water. Always add acid granules to water, not the other way around!  This solution is not as strong as that recommended on the Sparex can, but then I’m not trying to sell you more Sparex (I don’t follow the “repeat” part of the instructions on shampoo bottles either). My solution strength works fine.  I find if the solution is TOO strong, it doesn’t work as well.  More is not always better. I buy my sodium bisulfate at a pool and spa store that sells it as dry acid to lower the pH of hot tubs.

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16 Responses to Gah! Pickle Turned My Silver and Brass PINK…

  1. evarel says:

    I love your solutions for everything, descover your blog is like discover a new teacher, thak you so much for share all this information, I really need it

  2. Laura says:

    On this subject, I’ve been told to have a separate pickle for brass. I typically work w/silver and copper, but have recently introduced brass. What type of pickle do I use if I solder a brass cut out onto a sterling silver ring, etc.? THANKS!

    • julialowther says:

      Hi Laura, You don’t need a separate pickle for brass. You can use the same type of pickle and the same pot of pickle that you use for copper and silver. So that solves the problem of the silver ring with brass soldered onto it :). Best, Julia

  3. Hi, I have asked so many people but no one has gotten back to me, I really hope you can help. I have just finished making a number of necklaces which have stainless steel chain, and sterling silver jump rings which I have just soldered closed. The silver jumprings are firestained and I need to pickle them but how can I do this when my jumprings are attached to stainless steel chains?

    Really appreciate your help!!

    • julialowther says:

      Hi Monique,

      In theory, the stainless steel shouldn’t affect the pickle, so you should be able to pickle your chain with no trouble. This only applies to STAINLESS steel, of course, other steel in the pickle will definitely turn your silver pink.

      I would try ONE chain in the pickle and see what happens. If it goes pink, then you will need to use hot water and elbow grease to remove the flux and fire scale from your other silver jump rings. Soak the piece in hot water, then use a soft brass brush with dish soap and warm water to scrub off the flux/oxide residue.

      Hope this helps! Julia

  4. Maggie says:

    Thank you thank you thank you! saved my piece from getting ruined 🙂

  5. Shay says:

    You are a life saver!

  6. Skyler says:

    I hope this is on topic enough to get some response. My silver turns a Matt gray after being in pickle. A second pickling seems to make it worse. It’s not firescale. It does not clean off with soap and water even with a brass brush. I have to polish it off adding to my time more than if I haven’t left it in pickle it all.

    I use salt/ vinegar pickle. The pieces are cast with stones in place. The pickle was fresh. Same results with castings from two different investment types.

    Question is does anyone know what the gray stuff is or why the gray stuff is suddenly appearing when it’s never been an issue previously?

    I’ve been reading other blogs and jewelry forums and it seems to be mentioned but never defined or suggested reasons it happ no or how to avoid this..

    All Ideas or thoughts are welcome.

    • julialowther says:

      Hi Skyler,

      I’ve had this happen to me, too, but I don’t know why it happens. In my case, it was a fine silver knitted chain, and I heated the chain gently with my torch, then re-pickled it, and it was fine, nice and clean, with no need to polish off the grey. I’ve read online that others have had this problem with sterling, and they fluxed the piece well, then heated and pickled, and had the same results I had, namely, the pieces came out of the pickle clean with no grey surface. Not sure how this would work with stones cast in place, but if the piece can take the heat, I would try fluxing/heating/re-pickling and see what happens!

      Good luck and do let us know what your results are :), Julia

  7. Pierre says:

    Hi. This is a nice tip but…
    If you use alum pickle, you won’t have any problem ! No copper flashing at all, and the piece comes out really shiny, almost polished. Also, you can use it to remove broken drill bits, as it will corrode steel in no time.
    It has to be used hot to work, and takes a bit longer, but it has no other drawbacks (and it’s really cheap, you can get it everywhere arround the world, look for “shaving alum” or “alum crystals”)

    Anyways, thanks for the tip, it’s really precise and well-explained 🙂

  8. Jan says:

    Can I use superpickle for brass soldered onto copper? After pickling in sodium bisulfate, the whole piece lookes like copper instead of two metals. Thanks.

  9. Laura Jones says:

    Just got through pickling a ton of silver, copper and brass jewelry only to pull it out PINK! Of course I panicked and found this. Too late and too tired, but I’m trying this to,or row after work. Sure hope this works!!!

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