|
True brass is an alloy of copper and
zinc. It tends to oxidize (tarnish) quickly when exposed to air,
which is a major reason why most brass is given a clear coating
of lacquer to prevent this condition. Additionally, most metal polishes
contain solvents and detergents to remove the tarnish, mild abrasives
to polish the metal, and oils to act as a barrier between the raw
metal and air.
Brass turns "black" when cleaning due to over-use and misuse of
polish. The biggest challenge to the upkeep of most metals, including
brass, is the removal and inhibition of tarnish. All substances,
especially metals, oxidize when exposed to air. Once tarnish is
removed, a chemical barrier should be created between the bare metal
and the air to inhibit the process from re-occurring.
|
