by Jasson Roser (reference: Julia Lowther Shoebox Studio)
Magic of the Amateur Jeweller
We are capable of some wonderful things by creating silver work along with stonework, cutting, polishing and “voila” a beautiful creation. Of course, there are a thousand and one tiny little things we do between the idea and the finished item. Yeah.
I have been working with metals for a very long time, originating in the blacksmith area. I am still amazed by what we can accomplish. Whether by brute force or the subtle magic of science.
Yes, science fits well into blacksmithing as well as with silverwork. Now, I always applied the simple rule of “don’t force it, get a bigger hammer”. Most metals respond well to the magic of the smith. Sometimes a big Neanderthal like individual with a great hammer and anvil, or more often in our case the smith can be of the look of the typical man, woman and, yes even child. The one thing they must all abide by is the Rules. With pretty much everything we do there are rules and silversmithing is no exception.
Not long ago at the club we had incidences of pink silver. Don’t get me wrong, it was amazing that silver when placed in a hot pickle would remove any fire scale but also turn every surface of the silver “PINK”. Fantastic magical transforming my silver, to that of clean copper. Sign me up I need some lead and Merlin’s recipe for gold, and I’ll be quite content, yeah? Woohoo.
However, science is a cruel master, lead to gold still stays a mystery. I saw one of our instructors using a copper wire brush on said Pink silver, as you can see it’s difficult to remove. If you put steel or iron-based materials into a pickle your silver turns pink.
So, I’m not exactly happy with that, so I skulked away to my hidden lair (my house) and consulted the ancient visions of truth and wisdom (the Intergoogle)
I asked said entity “show me why silver goes pink ?” Now let me tell you, you must be more specific with your questions.
So, I asked again “oh great and wise inter google please show me the magic of why silver is turned to copper when I confuse myself by using iron-based tongs in the pickle”
To my astonishment the answer was displayed on my very screen. Not only the answer but the reason was illuminated alongside.
Behold my Brethren the answer to the curse of PINK silver
Copper is awesome. It carries electricity through our world, and it makes many things blue, like octopuses’ 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 jewellery (ooh, shiny, pretty!), and we are still using it, a lot of it, in making jewellery today. Even when metal isn’t copper coloured, 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 jewellery 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 bisulphate dissolved in water. After you solder something, this handy acid cleans the piece by eating the crusty flux and oxides off the surface.
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 below 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 its 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.
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 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 dramatic…
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.
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.
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 mess. 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 quickly when it’s warm, you must 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,
Disclaimer- if you blow yourself up please let me know how so I can try too.