How to Repair More Severe Damage to a Finish

Chips and holes in a varnished or french polished surface can be built up by applying a ‘touch-in’ of the same finish in the depression, letting it dry, and adding more until you bring it level. For huge gashes, make cellulose ‘jam’ by pouring a capful of cellulose lacquer into a tin lid, letting it evaporate to become sticky, adding a bit more and letting that dry out, and so on. This is an ideal thick filler for damage to cellulose surfaces. Use a fine artist’s brush, and make sure your previous coat is hard before you apply the next one.

A scuffed, dull surface with multiple light scratches can be brought back into condition with fine steel wool (000 or 0000) and mineral oil, rubbed in the direction of the grain. Wipe the oil off, then wax or furniture polish the surface. You can buy french polish ‘revivers’, which should be applied in the same way and buffed, first with steel wool and wax and then a soft cloth.

french polished surface

For even more severe deterioration of french polish and cellulose, reamalgamate the finishes with their respective solvents. Varnish will not respond to this treatment because it hardens by reaction rather than evaporation, as do the acid lacquers. For french polish, soak fine steel wool in meths and rub it along the grain so that both the liquid and the action fuse the surface. This needs a delicate touch; you have to dissolve the finish enough to move it around, but not so much as to create ridges or inadvertently strip it. Wipe the meths off with a rag before the finish starts to go. The same method works for cellulose using thinners. If cellulose is badly cracked, paint the thinners along the lines with a fine brush and fuse it by pushing gently with the heel of your hand before you wipe the solvent over.

A professional’s trick for reamalgamating is flashing. But with the important addition of a wiped layer of mineral oil before you apply the meths. The finish softens and moves, but is not burned off because of the protective oil. Have the surface vertical so the flame travels upward, work quickly, and take every fire precaution.