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If a printed circuit board (PCB) is being used in a damp environment, such as outside or in a fridge, it is important to protect it. Lacquer is a thin polymer film that is sprayed or painted onto the PCB and components and this protects it against moisture as well as dust, chemicals and temperature fluctuations.

Many mechanical systems work by moving parts together - this creates friction that, over time, wears the product out. Lubricant is added to allow parts to slide past each other without causing friction and this slows down wear. For example, oil is used as a lubricant for bicycle chains to improve the performance of the bicycle.

Outer casings of electronic and mechanical products can have surface treatments added:

• anodising metal gives a coloured protective surface to a metal and is most successfully used on aluminium
• paint can be sprayed on or dip coated to give a protective and aesthetic covering
• flat surfaces can be screen printed with pictures and patterns that decorate and protect products

Powder coating is a method of attracting paint in a powder form towards an electrically charged object:

1. paint that is in powder form is sprayed from a paint gun
2. the paint is attracted to the electrically charged object
3. a fine and even coat of powdered paint covers the surface of the product and, once heated, the powder melts and produces a ‘run free’ paint finish

Dip coating is a popular finish for the handles of many tools and coat hooks. It is a straightforward process:

1. a piece of metal is heated up to around 250°C
2. once hot, it is then dipped into a polythene in powder form
3. this has air blown through it so an even coating of the powder is dusted onto the hot metal, resulting in a smooth and shiny coating on the dipped metal

Polythene is available in many colours and can help improve grip when applied to tool handles.