Pickle and Pickling

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Nancy LT Hamilton

Last updated:  9/9/21, 7/26/17

My pickle is dark green/blue and my silver is looking funky.  What do I do? A Conversation.

Question

Me:  Usually, the color has nothing to do with the strength of the pickle.  I use a  studio-dedicated Melita and matching Melita coffee filters to strain my pickle (see Maintaining Your Pickle, on my site).  Strain it into a plastic container like a gallon water or milk jug – cut the neck off a bit to hold your Melita safely, if necessary. You might want to do this over a plastic tub or in a non-metallic sink.  Absolutely wear eye protection that is rated for chemicals.  I turn on my ventilation although, it is probably not necessary if the pickle is cold. If you spill the pickle soak a rag in a baking soda/water solution.  You’ll see the acid bubble as you wipe the surface.  Wash again with clean water.  Rinse the rag before putting it in the laundry.

Me:  What do you mean by “my silver is looking funky”?  Can you describe its appearance?

Her:  My silver is looking dingy, not pink like copper – darker, not clean.

Me:  Sometimes, little bits of steel fall to the bottom of the pickle pot and can contaminate the surface of the metal.  If this is happening, straining out those particles should help.  Sodium Bisulfate pickle (the chemical most often used in pickles), lasts a very long time.  I add water when the level gets low, add a touch more pickle if the pickle seems slow, and filter it every couple of months (the frequency of filtering depends on how much metal you process a day/week/month).

You also want to be sure that you aren’t introducing other chemicals into your pickle.  Sometimes, when etching or finishing our work, it doesn’t get rinsed properly and these other acids, bases or other chemicals can get mixed into the pickle.  The acid doesn’t really get weak or tired, it just gets contaminated.

Be sure to quench and even brass brush (especially after etching or using pitch), BEFORE you put your metal in the pickle!

Ensure that your tongs are rinsed in plain water before putting them back into the pickle pot.  I’ve seen dozens of people take their piece out of the pickle with tongs, then place the tongs into the baking soda bath and then use them – without rinsing – to place another piece into the pickle.  The pickle then bubbles because you’ve just added a base to an acid – effectively neutralizing your pickle, bit by bit.

How to know if your pickle is contaminated or not

Me:  Normal discolorations after pickling:

  •   Sterling silver has a whitish cast.  This is not a contaminant.  This is simply a very fine layer of pure silver that has formed because the copper, in that layer,  has been leached out due to the torch’s heat and the acid in the pickle.  Simply brass brush the surface and it will disappear or ignore it until you are at the finishing end of production. Tumbling will also remove it.
  •   A pinkish, copper cast to brass, bronze, or sterling.  This is also NOT a contaminant!  This pink cast occurs when soldering.  You may not see it until it has been pickled.  This often happens with brass, bronze, and sterling silver because they all contain copper.  The pink is simply copper (from the alloys) appearing on the surface.  To remove it, create a batch of Super Pickle.  This is basically, 50% hot sodium bisulfate pickle ( Sparex is one brand – you can also use a spa ph reducer – read the labels to be sure it is pure sodium bisulfate) and 50% hydrogen peroxide.  Mix together in a plastic or glass container, gently lower your piece, and wait a minute or two.  (Use copper, wood, bamboo, or plastic tongs to remove).  The pink will disappear.  Leave the Super Pickle out overnight (protect children and pets by putting it somewhere that they can’t access).  The hydrogen peroxide will alter and become plain water while the pickle will still be pickle.  Pour the pickle back into your pickle pot.
    • Don’t leave your metal in the super pickle too long as the solution will etch your metal, creating a matte finish.  I often intentionally leave my metal in too long to create this matte surface on my metal.
    • You can also get a pink color to your metal if it is in close contact with steel.  Often,  when using binding wire, small pieces or even large, get introduced into the pickle.  There is a reaction that occurs between steel, your metal, and the solution that literally plates your metal with the free-floating copper ions in your pickle.  This can be used in your favor if granulating gold and silver – if you need copper plating – for whatever reason.  This can also be removed with Super Pickle!

Her:  Oh, I’ve been stapling my little, plastic pickle bags closed.

Me:  That will cause issues!  You should stop doing that!  I use a very small, plastic measuring cup that I have drilled holes into.  You can also drill holes in a pill bottle or film canister too.

Plastic measuring cup to hold small items in pickle.

  •   Brown/black splotches.  Often, this means that oxidation on your metal has not been fully removed.  This can happen if your pickle is cold or has weakened or you haven’t left it in long enough.  The fixes are:
    • Heat up the pickle
    • Add a tablespoon (with a studio dedicated tablespoon) of pickle
    • And/or leave the piece in the pickle a bit longer.
  • Overall gray surface.  This has happened to me a few times and it’s a pain in the tush to clean up! (Can’t find a piece to photograph).  It happens sometimes if I leave my metal in the pickle too long (like overnight).  From what I could find through my research is that this gray surface is the result of the pickle etching the surface of the metal and then dirt and impurities, in the pickle, entering and becoming lodged in the metal.  I wrote to a few silver manufacturers and, obviously, searched the web AND read a few books (see the end of this post for recommended books on metal) trying to figure out what was happening.  At this point, I decided to change my pickle even though it only occurred when I left the metal in too long. That helped.
    • To clean off this gray coating, I had to torch and pickle the metal several times.
    • This is way more common if putting metal clay into the pickle pot.  I usually do that after soldering on sterling elements.  I think that is because the metal clay is more porous than sheet metal.

You can tell if your pickle is contaminated if the color is silvery, gunky or there is an oily layer on the surface – or any of the colors not listed under this heading.  At our jewelry studio at Chimera Art Space, I’ve seen it all and often find myself wondering what the hell people put into the pickle.  We have to replace our pickle often at Chimera due to these mystery elements.

End of conversation (sort of!).

Good Books on Metal

How to avoid pickle pot corrosion.

Question

I have had 3 pickle pots and all of them have corroded and rotted away.  I have learned to not use tap water, and to not let the solution boil … so I’m learning from these mistakes. I use the Rio Pickle solution. So I need to clean up the table/benchtop. The surface is covered in dried-up pickle pot liquid. How should I go about cleaning this? I am going to buy a new crockpot and now I’m going to only use distilled water and keep the setting on low. Does the crockpot need to be sitting on top of something … is that necessary? Like a drip collector cookie sheet idea of a thing except not a cookie sheet I know not to use anything metal with the pickle pot for the acid will eat away at it. What is the best crockpot to buy? A ceramic bin or plastic?

Answer

  I have my pickle pot on a cement board and have a big piece of acrylic behind it as well. The pickle always drips and splashes – which is why I wear eye protection and an apron!

The distilled water is important to not contaminate the pickle. For instance, my well has iron in it. The iron will contaminate the pickle and cause copper flashing. It probably doesn’t have much to do with the corrosion of the pickle pot but, I could be wrong.

On the clean-up: I wet a rag with my baking soda/water neutralizing solution and wipe down both the pot and the counter – once in a while. I also wash the lid in the sink. I wash the ceramic insert before I put in a new solution.  I then re-wash with a clean rag dipped in plain water.

After each pickle change, clean the ceramic insert (if applicable) well.  Scrub out all the crud in the pot and wipe down the sides and bottom as well.  Don’t reuse any sponges or brushes, used for cleaning, in any place but your studio.

Another thing to do is to pull off the control knob on your pickle pot (if possible) and clean under that with the baking soda rag and then wipe it up with the plain water rag. MAKE SURE THE POT IS UNPLUGGED FIRST.

  I recommend plugging your pickle pot into an electrical strip with an on-off switch.  Plug in a small clip light (or something similar).   With this setup, you need to turn the electrical strip on for the pickle to work AND the light.  When you are done for the day, and the light is on,  you’ll know that the pickle pot is also on.  I leave my pickle pot set to low and just use the electrical strip as a control.  When you leave for vacation or for extended periods of time, unplug the strip – just to be on the very safe side of things!

I buy all of my pickle pots at junk stores for about $5.00 to $15.00 (for $15 it has to be large, very handsome, and perfect!). Don’t buy crockpots/pickle pots that have metal around the lids or metal on/in the insert. The one I have has a screw in the lid to hold the knob.  It has corroded.   I should have sealed it with a strong acrylic sealer or a plastic product like Plasti-dip, before using the pot!

  Here’s a photo of what mine looks like. Note the corroded metal screw on the lid (the only metal present). Also, note that it’s time to clean my pickle pot!!!

Why is my brass turning pink and how to remove it?

See this answer in Q&A: Metals, too!

Question

I have a problem that’s left me perplexed even after reading almost every article on the internet about flux and pickle. I apply flux on my brass, heat it up, solder, everything is nice, I put it in the flux and the fluxed parts turn pink (I don’t use steel tweezers or anything), only the fluxed parts, and I tried super-pickle and everything, and the only way I can take it off is by sanding it (A lot!) which is not only a pain in the butt but also extremely difficult when sweat soldering (it removes all the nice details I made).

Answer

You have there a piece of brass that has been heated.  This happens all the time with brass and bronze and is so much easier to fix than by sanding!  It is basically copper flashing.  See my page for more information on what is happening.  I remove the pink coloration by mixing 50% sodium bisulfate pickle (either spa ph reducer or a pickle like Sparex No. 2) with 50% over-the-counter hydrogen peroxide.  It usually takes less than a minute to work and, if you leave the liquid (minus your piece of metal) overnight, you can pour the pickle back into your pot.  I don’t know if this works with pickles that are not made from sodium bisulfate (Rio Pickle and others).  Here’s the link to my Pickle Page and also to my Removing Copper Flashing page.  I know this will help – no more sanding!

What do I think of Citric Acid Pickle?

9/26/16

Question

I was wondering if Citric Acid Pickle works just as well as the Sparex? I am just thinking of the environment.

Answer

I used the citric acid pickle for 6 months.  There are three things that I don’t like:  1.  It is nowhere near as strong so, it takes at least twice as long to clean the metal.  2. It grows mold on the surface if you don’t use it every day. 3. It doesn’t last as long as the sodium bisulfate pickle.

What I like:  Enviro friendly, easy to get rid of, no toxic fumes.
So, maybe by now, you’ve tried it.  If you have, I wonder if your opinions are the same as mine.  I’m back to my sodium bisulfate, BTW!

What type of pickle to buy and what about disposal after it is used up?

Question

I’m not sure what kind of pickle to buy.  I don’t want to go through all the bs of filtering it, calling about hazardous materials,  if I can avoid it.  Do I still buy the bisulfate (word? sp?) because wouldn’t it work faster or better than the green stuff? (Sic)
Answer

I’d just use sodium bisulfate pickle (spa ph reducer) or a jeweler’s pickle like  Sparex #2. Be sure to only use #2 for silver, gold, copper, brass, bronze, nickel.

 With getting rid of the pickle:   if you neutralize it (another outside activity) – with the pickle pot (the ceramic section only!) placed into a large plastic tub – it is safe to pour down the drain.  The issue is the soluble copper that is in it (copper sulfate).  You’ll notice it because your pickle will be green.  If you only work with fine silver, you won’t have any green pickle because there’s no copper around to generate it.  But, generally, we work with copper alloys like sterling, brass, bronze, and copper itself so, we are going to be seeing a lot of green/blue pickle.

So, what you can do – if you have a place to do this in – is to (after neutralizing) let it sit and evaporate. Then, scrape out the green/blue crystals (while wearing gloves – nitrile, safety glasses, and an appropriate mask (probably a 3M N95 would work but, check with safety pros first), bag them, and take them to the hazardous waste department.  The crystals do not take up much room and it could be years before the bag is full.  Put it into another plastic container, just in case there is some active acid still in it. Read MSDS on copper sulfate and make good choices.  I am not an expert on the effects of the chemical!  I just know what I read.
My big concern is that nothing living gets into it:  pets and humans, during the evaporation process (it could be months).  The last time I changed my pickle, I placed the neutralized pickle into an old 2.5 gallon water container and it leaked all over the counter.  Unfortunately, I didn’t notice it right away and it started eating up the base of my hydraulic press.  So, don’t use that type of container!  Maybe purchase a gallon container (the container size depends on the volume of your pickle pot) with a plastic, screw-on lid – or get a Costco-sized jar of mayonnaise and dump the mayo or eat a lot of sandwiches!  I imagine, that you could punch some holes in the container’s lid and let it evaporate over time.  Label it as to its contents, as well as marking that it is hazardous – I like to draw a big skull and crossbones.  I have had several instances where I forgot what was in a container – because I didn’t label it. Think mystery food in the freezer! Who knows what it is and who can we talk into trying it!  It could be frozen dog food for all we know!
Whatever pickle you use, you will have the copper issue.  I used the citric pickle and wasn’t that thrilled with its strength and longevity.  It still turned green so, I would have to change the pickle more often and have a bunch of evaporating pickle all over the studio!  No!!!!  I’ve had the same pickle (sodium bisulfate – Rio Pickle) for months now and plan on having it for at least a year. – probably several!  I just add water when it gets low, and as you mentioned, use a coffee filter and Melita, to remove particulates. Easier than neutralizing and evaporating!

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