Download - 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?
© Pearson Education Limited, 2008. Copying permitted for the purchasing institution only. This material is not copyright free.
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
© Pearson Education Limited, 2008. Copying permitted for the purchasing institution only. This material is not copyright free.
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?
© Pearson Education Limited, 2008. Copying permitted for the purchasing institution only. This material is not copyright free.
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?
© Pearson Education Limited, 2008. Copying permitted for the purchasing institution only. This material is not copyright free.
Painting and Decorating NVQ and Technical Certificate Level 2, 2nd Edition
Surface coating defects