Looking after your bronze.
You should wax your bronze periodically to preserve its
patina and add lustre.
And avoid knocking it with hard objects or you may chip the
patina, which is a very thin layer of corroded or oxidised
metal which has been created by adding various chemicals to
the sculpture.
Different climates require re-waxing on a more or less
frequent basis.
Keep your bronze clean and free from dust, but do not ever
use any cleaning products or solvents on it.
If you should need to give it a more thorough cleaning once
in a while use warm soapy water and allow to dry thoroughly
before waxing.
Let your bronze warm up on a sunny window sill for a bit,
or use a hairdryer before painting on some paste wax (I use
Johnson's paste wax from the hardware store) with either a
paintbrush or toothbrush.
After your bronze has cooled down again (perhaps wait until
evening) and the wax has dried to a dull finish, rub it
with a soft cloth to bring out the shine.
You can do this as often as you like, but you'll need to do
it more often to outdoor bronzes than indoor ones, unless
you want your outdoor bronze to continue changing over
time, which some people prefer.