Powder coating is a great way to protect metal and other materials, even MDF for example,

wheel150x150Powder coating is a type of coating that is applied as a free-flowing, dry powder. The coating is typically applied electrostatically whilst hanging from a metal frame and earthed to the powder coating machine, and is then cured under heat (in the ovens) to allow it to flow and form a "skin". The powder may be a thermoplastic or a thermoset polymer. It is usually used to create a hard finish that is tougher than conventional paint.

Powder coating is mainly used for coating of metals, such as alloy and steel wheels (pic is of a wheel we did), household appliances, aluminium extrusions, drum hardware, and automobile and bicycle parts. Newer technologies allow other materials, such as MDF (medium-density fibreboard), to be powder coated using different methods.