Copper does not rust, but it stains easily and water
makes black spots on it. Soot in moist air reacts with the metal to
produce a green deposit called 'verdigris'. Clean off verdigris and
dirt by rubbing hard with a paste of powdered chalk and methylated
spirits on a soft cloth. Use a fine steel wool on stubborn areas, but
beware not to scratch your antique piece in the process. The final
stage of polishing is to use a metal polish - a soft cloth buffing
wheel on a power tool gives a deep shine, but over large surfaces,
polishing by hand with a soft cloth achieves a finer finish.
Clean
a brass antique by washing it in detergent, then rubbing it with a
solution of 1-heaped tablespoon of salt and 2 tablespoons of vinegar to
a pint of water. Clean the old polish and dirt out of engraved brass
with a solution of ammonia on a toothbrush, then with detergent and
finally with clean water. Immerse badly corroded brass in a strong warm
solution of washing soda for a hour, then wipe or brush the antique
piece. If all the corrosion does not come off, repeat the process.
Brush the stained parts with a glass brush, obtainable from a
jewellers' supplier. Rub off spots of corrosion with scouring powder on
a cloth or, if they are bad, with fine steel wool. Here, also, one
should be very careful not to damage the antique with excessive
rubbing. If scratches cannot be prevented then polish with a paste of
whiting - a finely ground chalk obtainable at DIY shops. Dirty brass
handles and fittings on antique furniture should, if possible, be
removed before being cleaned. Otherwise, cleaning with polishes and
lacquers will surely damage the wood.
Metal polish, a soft cloth
and hard rubbing produce the best results on both metals and of course,
the likelihood of damaging your valuable antique this way will be
significantly reduced. Delicate engravings might be rubbed away using
metal polishes so in this case, vegetable oil on a cloth and some extra
rubbing will be a better option to bring it to a shine. On deeply
engraved antique pieces, use a medium-soft toothbrush to get metal
polish into all parts, then with a soft brush inside a duster to get it
out. Finish with a soft cloth.
There is no substitute for the
sheen obtained on copper and brass antiques by regular polishing, but
clear lacquer, obtained from DIY and art shops, saves much of the work.
Because lacquer goes cloudy in cold weather and picks up dust in the
atmosphere, it should be applied in a warm dust-free room. Spray or
brush the lacquer on to the metal and, if it eventually starts to crack
or break up - acetone will remove it. If an antique has been mended
with soft solder, paint on a coloured lacquer to match or approximate
to the true colour of the metal. Do not apply lacquer to a mended spot
if the antique is 'raw', this will make a brighter patch that may not
match the original sheen.
Dents in copper and brass antique
pieces are best removed by pressing the metal against a short length of
wood, shaped at one end to fit the curve of the damaged article. Press
and rub against the shaped end until the dent is removed. Hammering is
not advisable, although hammering with a 'planishing' hammer from the
inside against a leather cushion is a professional method. Fractures in
brass and copper antiques can be mended by soft soldering but cast
brass is heavy and hard soldering or brazing makes a much better job of
such joins.
