- What Is Jewelry Pickle? Jewelry pickle is an acid solution used by jewelers to remove oxides formed on metals like silver, copper, and low karat gold during heating processes such as soldering.
- Common Types of Jewelry Pickle: The most common commercial pickle is Sparex No. 2, but alternatives include pH Down for pools, vinegar and salt, and citric acid.
- How to Use Jewelry Pickle: The typical process involves heating the metal piece, allowing it to cool, then placing it in the pickle solution until the oxides are removed.
For the beginning silversmith, a whole new world of terminology needs to be memorized. It can often seem a bit overwhelming, especially when it comes to things like pickle. It’s a familiar term bandied about in an unfamiliar way after all.
So, what is a jewelry pickle? What does it do? How do you use it?
Well, read on and we’ll enlighten you across the board on your questions!
What is Jewelry Pickle?
Pickle is an acid used by jewelers in-between stages of construction that involved heating. The most common commercial formulation is a dry powder that turns water into a dilute sulfuric acid solution.
When silver, copper, and low karat gold are heated they’ll form oxides on the surface of the metal. This is known as fire scale (not to be confused with fire stain) and it’s rather unsightly. While you can just abrade away the material, that involves turning some of your precious metal into dust and will require you to refinish the piece.
Pickle will remove this fire scale.
The term has an interesting etymology. The original solution used was created by adding a substance called alum to water, the same alum that’s used to pickle vegetables. Alum is slow-reacting, however, and has largely been replaced except for expedient work when other acids are unavailable.
The most common jeweler’s pickle these days is Sparex No. 2 Pickling Compound. It’s a powdered blend of sodium bisulfite that turns water into a relatively stable acid solution at a good concentration for both safety and handling the job.
Other common solutions include:
- pH Down for pools
- Vinegar and salt
- Citric acid
You don’t necessarily need to buy pickle if you’re silversmithing. There are quite a few DIY recipes out there that work just as well.
Read More: How To Make Your Own Jewelry Pickle
How Does Pickle Work?
All pickles work the same way, regardless of it’s a DIY mix or a professional one.
Noble metals, such as gold and silver, are quite resistant to acids. Gold, for instance, won’t even dissolve in concentrated nitric acid! Fortunately, the oxides on them do dissolve in the acidic solution.
This has the effect of removing oxidzed material from the surface of the metal and leaving behind just the metal. Often, pickle will also remove copper from the surface of the alloy, leaving behind a white finish. That’s due to the fact that copper is more readily soluble than silver or gold.
The finish left behind is called depletion gilding, although some teachers erroneously refer to the process as “raising the silver.”
Essentially the acid dissolves the oxides and copper but not silver or gold. Pickle is also used with copper jewelry, where it dissolves the oxidized surface of copper more quickly than the pure copper molecules underneath.
How Do I Use Jewelry Pickle?
Use of pickle seems like it’s simple.
And honestly, it’s not worth it to overthink it too much. Everyone develops their own timing, methods, and determines their own acceptable safety risk.
Most of the time, pickle is used as part of the soldering process:
- Fire piece and make sure solder runs
- Air cool or quench the metal
- Place it in pickle
- Wait until oxides are gone
This is the safest and best way to do things. Your pickle pot should always be closed unless you’re popping it open to put in jewelry.
I learned about jewelry pickle from an old-school bench jeweler. His method is one of the very hotly contested ones: he quenches in the pickle to speed up the process. He’s done it for hundreds of thousands of operations over the course of his career and doesn’t have any horror stories about pickle to tell.
That said, when you do that you’re putting acid fumes into the air and you may splatter some pickle on your workbench. Neither of those is desirable.
Likewise, the acid could theoretically get into the pores of the metal and continue the process there. In silver, this could eventually lead to a brittle joint that breaks somewhere down the line. While I’ve seen this possibility discussed… I’ve never seen any proof of it happening.
Theory and reality don’t always mesh.
That said, I advise quenching in water then pickling. If you’re using a weaker DIY solution just make sure that it’s hot so you’re not waiting too long for the acid to do it’s work.
Avoiding Copper Plating
Unfortunately, pickle has a tendency to create copper plating anywhere that you touch a piece with steel or iron.
For that reason, you need to be aware of what metal is in the pot (even the springs in clasps can create a problem). Anything that touches iron in your pickle is going to end up being plated with a layer of copper that’s a few atoms thick.
Essentially your acid will electroplate anything that gets touched with iron. Copper or wooden tongs are usually used to remove material from the pickle.
You can actually use this to your advantage in some cases. For instance, I despise copper solder and frequently use silver solder on pieces made of copper. The silver seam that’s left after the soldering operation and filing can be plated by running steel over it, removing the silver color.
Long story short: just use copper or wooden tongs to remove stuff from the pickle and save yourself a headache.
Picking a Pickling Container
Pickle is an acid, so you can’t just throw it in any container and hope it works out. Even the safer options are notorious for eating metal, especially when the evaporated fumes do their thing over time.
Glass or ceramic are your only real options, especially since you want to be able to heat the solution.
Crock pots are an ideal container for your pickle. They’re made to hold low heat for a long time, the inserts are ceramic, and they usually have a glass lid. Those add up to an excellent pickling container.
If you’re using a cold pickle then a mason jar or other closeable glass container will work. An ideal top would have no metal exposed to the acidic fumes inside, but I’ve safely kept homemade pickle in a regular mason jar for months without any failures.
Cheap crock pots usually have a metal trim on the exterior of their lids. This will rust rather quickly, especially if you have a habit of leaving the pot on.
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