Surface Coatings

1. © City of Glasgow College
Charity Number SC0 36198
Surface Coatings

2. 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?

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

4. Evaporation – the
water/solvent
component
evaporates
Oxidation – the
paint
reacts with oxygen in
the air
Coalescence –
binder
particles fuse
together
into a film
How does paint dry?

5. Mixing a two-pack coating
Always
• 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?

6. Surface coating defects