The metals jewellers work with are chosen for three qualities: they are plastic (they can be worked without rupturing), ductile (they can be elongated without breaking, as in wire drawing) and malleable (they can be deformed). What is less often explained to beginners is that these qualities are not fixed. Every hammer stroke, bend and pass through the rolling mill makes the metal a little stiffer and more brittle. Keep working it without intervention and it does not politely refuse — it cracks.
That stiffening is called work-hardening, and the intervention is annealing: heating the metal and then quenching it in water. The heat causes thermal recrystallisation that relieves the stresses built up in the metal. Annealed regularly while being deformed, a piece of silver can be worked almost indefinitely into any desired shape or form. Annealing is not an occasional rescue operation — it is a cycle you repeat again and again at the bench.
Reading the colour
Annealing is done with a gas torch, moving the flame at an even rate over the entire surface of the metal. Even heating is the whole skill: overheating must be avoided because it results in structural weakness — and past that, a melted piece.
The reliable cue is colour. Silver is usually annealed when it reaches a pinkish colour; copper needs to go to a reddish colour. The moment the metal shows its annealing colour, extinguish the flame and quench. It sounds imprecise the first time you hear it; at the torch it is unmistakable.
Pickling: cleaning after the flame
Heating metal — annealing, fusing or soldering — leaves oxides on the surface, and soldering also leaves fused flux. Pickling removes both. The traditional solution is potash alum, sold as crystals that dissolve in water when heated. Keep the mixture in a heat-resistant bowl with a lid, warmed on a hot plate — heated, but never boiling.
One ordering rule is absolute: always quench the heated piece in water first, then soak it in the pickle. Dousing hot metal straight into the solution defeats the purpose.
The one contamination rule
Ferrous metals must never come into contact with the pickle. Contact with iron or stainless steel contaminates the solution and reverses its effectiveness — a classic beginner's mistake is fishing pieces out with ordinary steel tweezers. Use copper or plastic. The vocabulary from the jewellery course makes the grouping clear:
- Ferrous metals contain iron: iron and stainless steel.
- Nonferrous metals contain none: copper, bronze, brass.
- Precious metals — gold and silver — are nonferrous, and also precious.
Why this cycle shapes everything else
Annealing and pickling sit at the start of nearly every metalsmithing sequence — rolling sheet, drawing wire, forming, setting — because every one of those operations work-hardens the metal again. Watch an experienced jeweller and you will see the rhythm: work, torch, quench, pickle, work. Learning to read the metal's colour, and to respect the pickle, is the first real bench skill; everything after it becomes possible.
Grounded in the JDMIS Metalsmithing (MS100) course materials. To practise the full thermal cycle hands-on, see Foundation Metalwork Skills and Experience and Creative Silver Modelling Techniques. Related reading: How to Become a Silversmith and Precious Metals and Hallmarks.