Environmental factors such as heat and moisture (resulting from changing temperatures) can cause metal objects to corrode. It is important that metals are displayed and stored in an environment that is well ventilated and has a stable temperature. Salts and oils from hands can cause long-term damage to metals, so handle objects wearing nitrile or vinyl gloves.
Different metals react in different ways, so it is always useful to know which kind of metal you are dealing with. In storage, it is generally best to keep metal objects together and away from wood objects or furniture because these can give off acidic vapours.
Wash metals with warm water and a soft cloth. A soft non-wire brush or soft toothbrush may help to get into corners and remove dirt. A small amount of of liquid detergent can be used but it is important to rinse the thoroughly.
Do not use chemicals, cleaning solutions or tarnish removers, or any other unknown substances to clean the surface of an unknown metal.
For metal objects that are permanently outside, avoid exposure to chemicals such as fertiliser sprays, chlorine, pesticides, bug sprays, window washing products, ammonia or other household products.
Never use a cleaner that is abrasive, contains copper or iron, minerals, chlorine or window cleaning solutions. Also, do not use abrasive cleaning pads, steel wool or sandpaper on metals.