Let's start with what it is - pickling solution - used for cleaning oxidation from base metals and sterling silver. Sparex is one of the leading brands.
Back in the early 80s when I had my first real workshop area, a small room off the kitchen, I organized my tools so nicely by hanging them in a cabinet that hung on the wall above a counter top. (Now my tools are all piled up inside a cabinet!) I had my pickle pot sitting on the counter top. It was a simple, small Crock-pot with Sparex mixed with water in it. It was only turned on when I needed to use it. My children were young at the time, so I didn’t use it very often. In fact I was lucky to get to work on my jewelry once a month. Over time I noticed my tools in the cabinet were rusting. In the Dallas area this is not common, especially when they are inside a house.
As time went on the tools became rustier and the ones on the right side of the cabinet were worse than the tools on the left side The pickling solution was directly under the right side of the cabinet. That is when I learned that Sparex, when stored near steel tools, makes them rust. I cleaned my tools, moved the Sparex out to the garage near my husband’s tools, and my tools never rusted again!
Which Tweezers to Use with Sparex Pickle
There is a reason why you should only use copper tweezers to remove your metal from the Sparex pickling solution. That’s because steel tweezers causes a reaction in the Sparex solution. It can plate your work with copper!
For many years many jewelers, including myself, believed that if someone placed steel tweezers into the solution the solution was contaminated and we had to throw out the old solution and make new. Wrong! The reaction happens only when the steel tweezers are in the solution and the solution has had copper in it. As soon as the tweezers are removed, the reaction stops.
Sparex pickling solution absorbs the copper oxides from copper, sterling silver, brass, bronze, and rose gold, thus cleaning the metal. Over time, the solution takes on a blue tint. This is the copper suspended in the solution. The reaction with the steel tweezers is actually an electrical reaction. Basically, what is really happening is the electrical charge makes the suspended copper, in the solution, plate any other metal in the solution.
A Plating Trick
If you are soldering something copper and want to hide the solder seam, just place the copper item into some used Sparex pickling solution along with some steel wool or steel tweezers and the solder seam becomes plated with copper. Unfortunately, if you unintentionally plate your metal, the only way to remove it is by sanding it off.