Dial Silvering

Brass dials requiring re-silvering should be cleaned back to the brass with fine abrasive paper. If a 'spun' effect is required, put a nail in a piece of old board and rotate the dial around it while holding fine emery paper on the surface. Most repairers will have an old gramophone turntable dedicated to this task.

Fill numerals in etched dials with black engravers wax. If the old wax is just cracked, hold the dial over a spirit lamp to heat the wax just enough for the cracks to disappear. If the wax is missing or insufficient, add a few flakes of it to the numerals and heat gently.

Rub the surface back down again if necessary to be level with the dial. Rinse under hot water and rub silvering powder into the surface with a clean cloth or tissue. Rinse again and apply finishing powder. Rinse once more and when dry apply colourless lacquer. Only use lacquer formulated for this purpose, as many lacquers will dissolve the shellac in engravers wax spoiling the work. Only lacquer once and do it quickly and confidently. Too much friction on the wax will make it smear. Insufficient or surplus lacquer can cause 'rainbow' effects.

There are Fixative Sprays used by artists that can now be used in place of traditional lacquers but it must be one that won't dissolve the black wax.

Cleanliness is of paramount importance when silvering and almost all problems encountered are due to finger marks on the metal between cleaning and applying the powder. Silvering powder acts by chemical reaction with the metal, forming a silver amalgam and if this cannot take place evenly, an uneven colouring occurs.

If you feel the silvering powder isn't working well, experiment with a clean copper coin.

Repairing Your Own Clocks by Mervyn Passmore