surface coatings

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Painting and Decorating NVQ and Technical Certificate Level 2, 2nd Edition

To protect – stops steel corroding, timber rotting

To decorate – improves appearance, special effects

To sanitise – more hygienic, easier to clean

To identify – pipework and other

items

Why apply coatings?

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Painting and Decorating NVQ and Technical Certificate Level 2, 2nd Edition

Paint is either water-based or solvent-based. It consists of three parts:• thinner• binder• pigment.

Paint

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Painting and Decorating NVQ and Technical Certificate Level 2, 2nd Edition

Evaporation – the water/solvent component evaporatesOxidation – the paint reacts with oxygen in the airCoalescence – binder particles fuse together into a film

How does paint dry?

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Painting and Decorating NVQ and Technical Certificate Level 2, 2nd Edition

Mixing a two-pack coatingAlways • follow the manufacturer’s

recommendations • use the correct ratio of base to

hardener • be aware of the mixture’s pot

life.

What does the term ‘pot life’ mean?

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Painting and Decorating NVQ and Technical Certificate Level 2, 2nd Edition

Surface coating defects