Materials - woods

Question 1

What are the general properties of hardwoods?

Answer 1

-deciduous
-slow growing
-harder and stronger than softwoods
-close grain structure
-generally more expensive

Question 2

What are the general properties of softwoods?

Answer 2

-coniferous
-generally quicker growing
-needle like leaves
-not as durable

Question 3

Why are softwoods considered more sustainable?

Answer 3

Because of their fast growth rate.

Question 4

Is oak softwood or hardwood?

Answer 4

Hardwood

Question 5

Is mahogany softwood or hardwood?

Answer 5

Hardwood

Question 6

Is beech softwood or hardwood?

Answer 6

Hardwood

Question 7

Is balsa hardwood or softwood?

Answer 7

Hardwood

Question 8

Is teak hardwood or softwood?

Answer 8

Hardwood

Question 9

Is pine hardwood or softwood?

Answer 9

Softwood

Question 10

Is cedar softwood or hardwood?

Answer 10

Softwood

Question 11

Is redwood a hardwood or softwood?

Answer 11

Softwood

Question 12

What are the advantages of oak?

Answer 12

Quite strong
Tough
Attractive grain pattern
Hard
Large supply

Question 13

What are the disadvantages of oak?

Answer 13

Blights easily
Very heavy
Difficult to work with powertools

Question 14

Uses of oak

Answer 14

Indoor and outdoor furniture
Structural timber for buildings
Flooring

Question 15

Advantages of beech

Answer 15

Very hard
Water resistant
Non toxic
Durable
Straight even close grain

Question 16

Disadvantages of beech

Answer 16

The colour changes over time
Heavy
Loses its durability
Very hard and heavy

Question 17

Uses of beech

Answer 17

Furniture
Toys
Tool handles

Question 18

Advantages of mahogany

Answer 18

Hard
Rot resistant
Straight grain
Strong
Tough

Question 19

Disadvantages of mahogany

Answer 19

Poor workability
Dark colour shows dirt
Expensive
Very slow growing
Unstable

Question 20

Uses of mahogany

Answer 20

Veneers, furniture, floorboards

Question 21

Advantages of balsa

Answer 21

Lightweight
Buoyant
Natural insulator
Great strength to weight ratio

Question 22

Disadvantages of balsa

Answer 22

Highly flammable
Not waterproof
Weak
High import costs
Not resistant to moisture or attack

Question 23

Uses of balsa

Answer 23

Model bridge tests and buildings
Model aircraft

Question 24

Advantages of teak

Answer 24

Strong
Ease of workability
Attractive grain
Very durable
Resists warping

Question 25

Disadvantages of teak

Answer 25

Heavy, does not float in water Oily nature makes it difficult to glue well.

Question 26

Uses of teak

Answer 26

Outdoor furniture Boat building Exterior construction

Question 27

Advantages of redwood

Answer 27

Lightweight Good strength to weight ratio Resistant to shrinking Easy to cut and shape due to softness

Question 28

Disadvantages of redwood

Answer 28

Rots if not treated Warps if gets wet Coarse texture It needs a lot of maintenance Prone to denting due to softness Has knots

Question 29

Uses of redwood

Answer 29

Furniture Constructional members Veneers Good for decking due to straight grain

Question 30

Advantages of cedar

Answer 30

Hard Durable Resistant to rot Low density High quality finish Straight grain

Question 31

Disadvantages of cedar

Answer 31

Susceptible to insect attack Easily damaged

Question 32

Uses of cedar

Answer 32

Roof tiles Cladding Ship building Outdoor carving

Question 33

Advantages of pine

Answer 33

Relatively straight grain Easy to work Quite high strength to weight ratio

Question 34

Disadvantages of pine

Answer 34

Very knotty which makes it difficult to work Not durable without treatments

Question 35

Uses of pine

Answer 35

Construction Roof joists Floorboards and furniture

Question 36

What are the two ways of drying timber?

Answer 36

Air drying Kiln drying

Question 37

What is air drying?

Answer 37

The planks are stacked outside with wooden spacers between them to allow air flow around the timber Moisture is evaporated and the timber is dried out.

Question 38

Disadvantages of air drying.

Answer 38

It is a very slow method - 1 inch thickness of timber takes around a year Moisture content cannot be controlled as circulating air varies on time of year and weather

Question 39

What is kiln drying?

Answer 39

The timber is mounted on a trolley and wheeled into a fully enclosed kiln with steam being fed into it. Steam drives out the moisture

Question 40

Advantages of kiln drying.

Answer 40

Atmosphere and temperature can be controlled Moisture can be reduced to around 8% - suitable for furniture Quick process

Question 41

Disadvantages of kiln drying

Answer 41

Less environmentally friendly as is powered by fossil fuels. Quite expensive

Question 42

What is shrinkage?

Answer 42

If not seasoned correctly, newly felled timber will dry out in and uncontrolled way and then warp, twist and cup/bow.

Question 43

What are the two main methods of converting timber?

Answer 43

Through and through sawn Quarter sawn

Question 44

Disadvantages of quarter sawn over through and through sawn.

Answer 44

More expensive More wastage

Question 45

Advantages of quarter sawn over through and through sawn.

Answer 45

More decorative Less prone to cup or distort.