Alloys are mixtures of metals, blended together in varying proportions for economy, strength or beauty.
Bronze is the oldest alloy used by man. Essentially it is composed of copper and tin, though other metals have been - and still are - added in small proportions. Brass and pewter are other common alloys.
The process by which a thin coating of one metal is placed on another is known as plating. Examples are Sheffield plate (silver on copper), EPNS (electro-plated nickel silver) and Britannia metal, which is silver on an alloy of copper, antimony and tin.
Nearly all forms of tarnish and corrosion are caused by oxidization - oxygen in the air reacting with the metal - coupled with the action of impurities such as smoke, petrol
fumes or salt from sea air.
Moisture is another enemy of metal, and discolouration can be caused by some timbers, such as oak (coin collectors should not store coins in an oak cabinet).
Corrosion is a serious form of deterioration, caused, for instance, by acidic fruit juice left in a metal dish.
Clean pieces with care, for while most materials deteriorate if neglected, over-cleaning or careless cleaning can ruin a piece; never disturb the patina of an antique metal piece.
And remember that each time an item is cleaned, a minute fraction of the surface is removed. If in doubt, ask for professional advice.
There are many excellent products on the market for cleaning metal. Paint stripper or cellulose thinners will remove old lacquer finish.
Rust removers will remove corrosion on brass as well as rust from iron, and car cleaning abrasive will not scratch the surface. Do not use household cleaners or coarse sandpapers.
Wear rubber gloves while using rust remover and cotton gloves when handling a cleaned piece that is to be lacquered; fingerprints can prevent lacquer from adhering.
Unlacquered metals, kept in a city atmosphere, need routine cleaning every two weeks, but lacquered metal will keep their shine for up to a year.
Lacquering has no effect on the value of the items. Buy a good quality proprietary brand for the best results.
As an alternative to lacquering, if the metal will not be handled too much: give it a protective coating of wax furniture polish. This is a suitable form of protection for metals such as pewter, iron and steel.