Pickle is a liquid compound used to remove oxidation and flux from newly soldered jewellery. It is what you put your pieces in to clean them after soldering. Metal that has been soldered produces oxidation on the outside of it.
Just like convection oven heat cooks meats and meals, a pickle pot heat is used for cleaning soldered jewellery metals.
Pickles are (usually) a mixture of an acid or an acid salt and water that removes oxides and flux residues from metal. However pickle does not remove fire scale or fire stain and generally the only way to remove the fire scale is with abrasives.
Because of the corrosive nature of acids and acid salts, the handling and use of pickle requires specific safety precautions.
The amount and degree of safety precautions vary depending on the type of pickle. There are certain pickles, like vinegar or citric acid pickle, which are much less dangerous than say, sodium bisulphate or sulfuric acid pickle. For example consider wearing a mask and keep your face away from the pickle pot where possible.
Baking Soda (Sodium Bicarbonate) is commonly used by jewellers as a neutralizer or a base. A base plus an acid equals a neutralized acid.
After pickling your metal, you need to neutralize the acid – even if your pickle is made from vinegar or citric acid – with a base. If you don’t, the acid will continue to eat away at the metal. So, once you’ve removed your piece or pieces from the pickle, dunk it in a Pyrex or other type of ovenproof bowl containing a mixture of baking soda (a small handful) and (a few cups) of water.
Other pickling advice
Always use Distilled Water to make your pickle with.
The minerals and metals in your water will react with the acid. Many people have a lot of iron in their water which can coat your brass, bronze, silver, etc. with the copper present in your pickle pot (remember the section on copper flashing, above?).
You don’t need separate pots for different metals
A common misconception is that you need separate pickle pots for silver and for base metals (brass, copper, or bronze). This is simply not true.
All pickles work best when warm – Don’t boil.
When mixing up a new batch of pickle, remember to add the dry acid to the water. Don’t put the water into the acid. This is because if you add acid to water, the solution that forms is very dilute and the small amount of heat released is not enough to vaporize and spatter it. So always add acid to water, and never the reverse.