Surface finishes

Question 1

What are the two types of paint called?

Answer 1

Undercoat and top coats

Question 2

What is the undercoat?

Answer 2

The first layer of apint

Question 3

Pros of a undercoat?

Answer 3

.covers up previous colours
.cheaper than applying extra layers
.helps layers of paint to stick.

Question 4

What are the 2 types of top coats?

Answer 4

.gloss paints
.polyurethane paints

Question 5

What is a gloss paint ( key words.)

Answer 5

.hardwearing
.waterproof
.lots of colours
.apply the in the direction of the grain
.glossy
.used in interior designs

Question 6

What is a polyurethane paint? ( key words.)

Answer 6

. tougher
. childrens toys
. sprayed on for smooth finish.

Question 7

Why would you use varnish?

Answer 7

If you have an attractive grain, because it is clear.

Question 8

Name 2 types of varnish?

Answer 8

.Yacht varnish-waterproof and flexible.
.Polyurethane varnish-interior uses and hard wearing.

Question 9

What is the process called when treating wood with wood preservatives?

Answer 9

Tanalising- helps to prevent insect attacks an decay off wood.

Question 10

Name the key steps of tanalising?

Answer 10

1) timber is placed in treatment tank.
2) air is removed from tank creating a vacuum
3) tank is flooded with preservatives
4) pressure is supplied which forces the preservative deep into the wood.
5) excess preservative is removed and timber is left to dry.

Question 11

What is tanalised wood used for?

Answer 11

Out door furniture and fences.

Question 12

How do you prepare metals before adding a finish?

Answer 12

. smoothed first by filing.
. removing grease with a paraffin or degreaser.

Question 13

What is dip coating?

Answer 13

. metal is evenly heated then plunged into a fluidised powder.
. placed in oven
. smooth finish

Question 14

What can dip coating be used for?

Answer 14

.tool handels

Question 15

What is powder coating?

Answer 15

. plastic powder is sprayed using an electrostatic gun.
.spray gun gives powder an electric charge
. particles repell others due to the same charges so you get an even coat.
. heated in oven

Question 16

What is galvanising?

Answer 16

coating iron with a more reactive metal, so the more reactive metal will react with the oxygen or water instead.

Question 17

Why dont plastics need surface finishes?

Answer 17

because they are resistant to corrossion and decay.

Question 18

How can you remove scratches from plastics?

Answer 18

wet and dry paper polishing.