An ingot is any mass of cast metal, usually rod-like or rectangular. Making one is within reach of any metalsmith with a crucible, heat enough to melt metal, and a suitable mould — and it is how the bench turns a jar of scrap into usable material. When ready-made sheet or wire is not at hand, you can process pieces of metal into home-made sheet and wire, choosing the ingot mould's shape with intent because it largely determines what the metal can be processed into. As a bonus, it recycles unused bits of precious metal: cost-saving and satisfying in equal measure.
Step 1: Prepare the mould
The mould must be clean — any foreign particles become embedded in the walls of the ingot and resurface later as imperfections in the rolled sheet or drawn wire. A drop of machine oil for lubrication is advisable.
Step 2: Melt and pour
Place the clean metal in the crucible and always add a pinch of flux — boric acid powder — over it: this prevents oxygen being included into the melt. Heat until the metal is completely fluid, indicated by a shimmering layer on the surface. Then pour slowly and steadily, without stopping, into the mould. Wait for the metal to solidify before removing the ingot, and leave it to cool on the soldering block.
Why alloy at all?
Most precious metals in their purest form are too soft for durable jewellery, so they are alloyed with other metals for strength against daily wear. But purity carries intrinsic value that wearers care about — so the alloying is exercised with care: add only enough alloying metal to impart the needed strength, without compromising the majority component. Ready-made sheet and wire come pre-alloyed to commercial recipes — sterling, 925, being the most familiar silver alloy — and the same recipes can be mixed at the crucible by weight when you are making your own.
Rolling sheet
Once the ingot has cooled, it is processed into sheet or wire — simple in theory, tedious in practice: the ingot is either flattened (sheet) or funnelled and stretched in a controlled manner (wire) until the desired thickness is reached. The ability to work precious metal into extremely thin sheet and wire goes back to the ancient Egyptians; for thousands of years it meant laboriously hand-beating ingots with a hammer, until industrial equipment — and the bench-top rolling mill — arrived. Repeated rolling work-hardens the metal, so the annealing cycle from the bench repertoire runs through this whole process.
Drawing wire
For wire, the rolled rod must first be filed to a cone-shaped point at one end — that point gets fed through the draw plate. The untouched other end tells you at which hole of the plate to start. With draw tongs gripping the point, the wire is pulled through successively smaller holes, lengthening and thinning it step by step to size. Like rolling, drawing work-hardens; anneal between passes.
Ingot to sheet to finished piece is the oldest supply chain in metalwork — and doing it yourself, at any scale, is the difference between buying materials and truly making them.
Grounded in the JDMIS Metalsmithing (MS100) course materials. Learn the melt-roll-draw cycle hands-on in Foundation Metalwork Skills; see where the material ends up in Fabrication vs Lost-Wax Casting and Annealing and Pickling Silver.