An accomplished painter would never demand less than a beautiful frame for a magnum opus — and the same is true of a metalsmith and their jewellery. No matter how competent you are in every other aspect of the craft, a good finish is an absolute necessity to present a piece in its entirety. More than any other factor, the finish is the initial tip-off as to whether a piece has been well made.
Even the deliberately 'raw' look popular among contemporary jewellers is no excuse: it still requires an immaculate preliminary finish, because the surface must be prepared before the treatments and effects that create the desired outcome can be applied properly.
Sanding: the grit ladder
After hammering, soldering and everything else, a piece bears evidence of its formation — bumps, dents, scars, unsightly blobs. Files handle edges well, but for smoothness and consistency across wider surfaces the complementary process is sanding: wearing down inconsistencies with sandpaper until the surface is even.
The coarseness of sandpaper is its grit — lower numbers coarser, higher numbers finer. The correct method is a ladder: start with the coarsest grit necessary to remove the deepest imperfections, then move through increasingly finer grits, each one removing the impressions left by the previous. Skipping steps is visible; the scratches of a coarse grit always show through a too-fine finish.
Tools that keep sanding flat
- DIY sanding sticks — wrap and adhere sandpaper around small handheld planks and use them like files. Tightly-wrapped paper on a flat surface delivers a far more even cleanup on flat surfaces than fingers ever can, and it removes the uneven pressure your fingertips introduce.
- Split mandrels — tear sandpaper to size, insert one end into the split of the mandrel, wrap the rest, and mount it in the flex shaft. This combines sandpaper's flexibility with motorised speed. Stop periodically to inspect: over-sanding on a mandrel is easy, and it costs detail or structural thickness.
And the caution that belongs in capitals: never allow sandpaper to come into contact with a gemstone.
Polishing: the final touch
Polishing communicates a piece's beauty and desirability — eyes are drawn naturally to the sparkle of an immaculate, mirror-shine piece. Before modern machinery all polishing was done by hand; machines now take the majority, but remnants of the work still need a human touch.
Hand-polishing is rubbing a suitable textile — often leather, cotton or microfiber — coated with a polishing compound or abrasive paste over the piece until the desired effect appears. For hard-to-reach areas and inside corners there is thrumming: a mass of loose fibres, or string, charged with polishing compound, worked into interiors no finger could reach.
Buffing brings in felt discs coated with compound, attached to the flex shaft or polishing motor — speed and consistency for outside surfaces, always after the sanding ladder is truly finished. The finish is the last thing done and the first thing seen.
Grounded in the JDMIS Metalsmithing (MS100) course materials. Practise the full finishing sequence in Foundation Metalwork Skills and Experience; for the step just before it, see How to Bezel-Set a Cabochon — stones are set only after the piece is completely finished.