Pickling is something that metal smiths are doing all the time. We forget that there’s a lot we do in the jewelry-making process that most people know nothing about.
No, we aren’t pickling cucumbers, carrots, cabbage, etc. We use a warm solution of sodium bisulfate after we’ve soldered metal. The pickle removes oxidation. We can also use it before soldering to ensure that the metal is clean.
What is it?
A warm solution of sodium bisulfate. It’s a mild acid.
Why is it called pickle?
Before sodium bicarbonate was available, jeweler’s made their own pickle solution with alum. Alum is used to make pickles. I distinctly remember my grandma using alum for her pickles. There is another solution of citric acid and vinegar to use as pickle.
What’s it for?
When soldering metal, you can clean the metal before soldering it by letting it have a swim in the pickle pot. But it’s most common to use pickle after you solder. The pickle removes the oxidation from the metal.
Oxidation happens when heat is combined with a metal alloyed with copper and oxygen; like when soldering!
I keep my pickle solution in a wee slow cooker (that’s it in the image above). Often jewelers will pick up a Crock-pot at a thrift store and use it as their pickle pot. I may need to do this soon because I’m making larger piece and my mini pickle pot isn’t big enough!
A lot goes into the process of making jewelry. There are many steps, lots of tools and techniques as well as chemistry. There's always more to learn!