Section 5B Timber Based Materials

Question 1

Safety issues to consider when working

Answer 1

Wearing PPE in case of spillages - used to protect clothes, hands and eyes (safety goggles)

Precautions with heat to avoid burns

Question 2

Example deforming or reforming process for timbers and woods

Answer 2

Steam bending - could be used to create the backrest and seat of a chair
used to make it easier to bend the wood into a desired shape

Safety: wearing PPE in case of spillages to protect clothes, hands, eyes
Precautions with heat to avoid burns

Question 3

Turning (DT)

Answer 3

Wastage process typically done using woods or metals - material taken off is waste material
Wood lathe used
Wood is turned in a ROTATING CHUCK and the tool is stationary being moved into the path of the work piece
Speed of the work piece rotation is altered to reflect work piece diameter and the material being turned
Long pieces of work need additional support and hence are turned between centre
Lathes can produce bowls and spindles in wood, bore holes, turn threads and allow for drilling operations to be accommodated in all materials

Question 4

Benefits of well managed forests

Answer 4

Provide an environment for leisure activities

Employment

Question 5

Thinning forests

Answer 5

Managed forests contain trees of different ages
When trees are finally felled they are replaced with new seedlings
Young trees are thinned at around five years old

Question 6

Felling

Answer 6

A tree is ‘felled’ when it is cut down

Traditionally this was done using a hand axe or long saw
Modern felling is done using a chainsaw or agricultural logging machinery that can fell a tree, de-branch it and cut it into equal length logs in one action

Question 7

Timber conversion

Answer 7

Felled trees are cut into manageable lengths to be converted into timber planks and boards

Timber is supplied in two main finishes: rough sawn or planed all round (PAR)
Rough sawn timber is often used for exterior tasks like fencing
PAR is smoother and has been planed down on all sides and commonly used indoors

Question 8

Green timber

Answer 8

Newly felled unseasoned trees

very wet, with more than 50% moisture content
can be more difficult to work with for interior applications
Timber for exterior applications should have a moisture content of less than 20%
Timber for domestic furniture should have a moisture content of less than 10%

Question 9

Seasoning timber

Answer 9

reduces its moisture content
2 methods of seasoning are air or kiln drying

Question 10

Timber faults

Answer 10

Faults can occur as timber dries. These include:
Bowing
Splitting / cracking
Springing
Cupping
Twisting

Faults can make the timber unusable and increase the amount of wastage
kiln dried timber is less prone to faults than air drying
the end grain of timber planks is often covered with a special sealant

Question 11

illegal logging industry

Answer 11

Demand for more exotic timbers like teak and mahogany has created a huge illegal logging industry

Trees are felled unsustainably
Illegal logging destroys vast areas of rainforest and causes desertification, deforestation and ultimately plays role in global warming

Question 12

Timber provenance

Answer 12

Timber provenance is regulated by bodies such as:
FSC® (Forest Stewardship Council®)
PEFCTM (Programme for the Endorsement of Forest Certification)
In UK, sustainably managed forests must be FSC or PEFC accredited

Question 13

Manufactured boards

Answer 13

come in large sheets, often made from waste or recycled wood and adhesives
are usually produced using lamination or compression techniques
are often covered with veneers of higher quality timber
are composite materials - made up of 2 or more materials

Question 14

Laminated boards

Answer 14

Lamination is the technique of layering materials using heat, pressure and adhesives
Veneers (thin layers) are layered with the grain direction of each layer at 90° to each other - odd number of layers always used
Laminated boards are reinforced and can be made waterproof through process of lamination
Laminated boards are more aesthetically pleasing as a sheet of veneer is added above and below.

Question 15

Wood compression

Answer 15

Compression uses adhesives, heat and pressure to combine shreds, chips or pulp to produce a larger board

eg. Chipboard

Question 16

Rotational veneer production

Answer 16

Veneer can be made by rotating a tree trunk on a large industrial machine similar to a wood lathe
creates a long ribbon of veneer that can be cut to length

Question 17

manufactured board advantages and disadvantages

Answer 17

+
Available in large sheets with few faults or defects
Aesthetic flaws like knots can be eliminated, boards require very little finishing
Available in a vast range of surface finishes
Made of wood that might otherwise go to landfill, such as sawdust and low grade timber

-
Adhesives used in manufacture can be hazardous when inhaled
Adhesives used in manufacture can also blunt tools quickly
Many traditional woodworking joints cannot be used and the edges are hard to finish
Boards are prone to absorbing moisture

Question 18

role of wood

Answer 18

Wood has been used over centuries for many purposes, both practical and decorative
useful and versatile material
Aesthetically pleasing
good insulator of heat
Durable and tough
Wood generally has a good strength to weight ratio

Used in furniture and building structure

Question 19

Softwood

Answer 19

comes from coniferous trees - have needles, are evergreen, and they keep their needles all year round
Softwood trees grow faster than hardwood trees making it relatively cheap and readily available
grain is wider making it more absorbent - problem as water from bad weather could be absorbed, weakening the wood

Question 20

Hardwood

Answer 20

Sourced from deciduous trees - drop their leaves in the autumn and new leaves grow in spring
Hardwood is slower growing and is therefore more expensive is it is not as readily available as softwood
Sought after for its variety of colours and grains, it has good aesthetical and physical properties
It has a closer grain, making it more dense and hardwearing

Ash is very tough, but also flexible and shock resistant
Beech is tough and very durable with a fine finish
Oak is tough, hard and durable with a variable grain

Question 21

Balsa wood

Answer 21

soft and lightweight material - hardwood
Balsa trees are very fast growing which gives the wood a coarse, open grain
living tree has large cells that fill with water – this gives the wood its spongy texture
Strong in relation to its weight and density, Balsa is used for lightweight, rigid structures such as prototypes, model bridges and model aircraft

Question 22

Why is mahogany expensive

Answer 22

Good durability, colour and aesthetics
Deep rich reddish brown hue gives beauty and warmth to furniture, musical instruments, boats and interior panelling

Unfortunately desire for mahogany has increased the destructive and illegal logging trade

Question 23

How are softwoods useful

Answer 23

lightweight and easy to work with
Larch is durable, tough and has good water resistance
Spruce has a high stiffness to weight ratio
Cedar contains natural oils which offer natural water resistance

Question 24

Common board - MDF

Answer 24

Medium density fibreboard - Very dense board which makes it tough
smooth surface makes it suitable for veneers and finishes

Question 25

Chipboard or
particle board

Answer 25

Good compressive
strength
Edges chip easily

Question 26

Plywood

Answer 26

Made up of alternative
rotated layers of glued
wood veneers

Available in various
forms including marine
ply for greater water
resistance

Question 27

PAR or rough sawn

Answer 27

Planks and boards are
stocked with different
finishes: planed all round,
and rough sawn

If ordering PAR
timber (planed all
round), the standard
size will be reduced
• This accounts for the material removed in planing

Question 28

Standard mouldings

Answer 28

Mouldings are decorative
timber components with a
shaped profile
Commonly used in crown trimmings in houses
• Mouldings can be made
from natural timber or
manufactured boards

Question 29

Wood fixings and components

Answer 29

Screws and nails
Dowel rods
Hinges

Countersinking screws helps achieve a smooth surface which is more aesthetically pleasing
Using nails in timber joints at an angle makes the nails fit better in the wood

Question 30

KDF

Answer 30

Knock down fittings
are often used for self assembly furniture (flat pack furniture and kitchen carcasses
Eg. Connecting or block fitting, Cross dowel fitting, Cam lock fitting

Question 31

Specialist tools for working with wood

Answer 31

Planes, chisels, saws, surforms and rasps
• Abrasive paper and sanding tools are also used to prepare a
surface for finishing
• The phrase ‘measure twice cut once’ is often used by crafts
people. What do you think this means?
• If you had three grades of glass paper – 80 grit, 120 grit and
200 grit, which one would you use first, which one second and
which one would you use last?

Question 32

Wood joints

Answer 32

widely used where a strong join is needed

Butt joint
Dowelled joint
Mitre joint
Housing joint
Mortise and tenon joint

Question 33

Flat-pack furniture

Answer 33

Manufactured boards are well suited to self-assembly products
They are generally less expensive than hand-made items
Arrives boxed making it easier to store and transport
Relatively straightforward to assemble with a basic tool kit

Question 34

Commercial manufacturing

Answer 34

Mass produced timber components are produced using CNC machinery
• This enables large quantities of equal sized parts or products to be produced
• Templates can be saved and
reused to help minimise waste
• Screw holes, slots and patterns
can be cut in one process

CNC machinery can cut, drill, shape,
mill and profile manufactured or
natural timbers
• Screw holes, slots and patterns
can all be cut in one process
• Machines can accommodate
big sheets of material
• Machines work quickly and efficiently enabling
a product to get to market swiftly

CNC wood lathes produce
cylindrical components
• Once programmed they are very
effective at producing complex
shapes and spirals
• Ideal for repeat production
• Lathes can accept large and
long pieces of material

Question 35

Mechanisation and automation

Answer 35

Automated machinery has changed the way industry
manufactures timber based products
• Improvements in manufacturing methods
have been embraced by designers
• Stringent quality control methods have
increased consistency and accuracy
• Increased availability of manufactured
boards means products can be batch
and mass produced

Question 36

QC

Answer 36

Quality Control
The process where products are checked to ensure
they meet the design specification
• They should also:
• function correctly
• be free of defects
• be consistent and accurate
• meet set size tolerances

Question 37

Tolerance

Answer 37

The total amount a specific dimension or property is
permitted to vary
• This can apply to hole depth, length,
angle, thickness, weight and elasticity
• A gauge can be inserted into a gap
or hole to check if the sizes fall
within tolerance
• If parts do not fit within the specified
tolerances they are discarded or recycled

Question 38

Surface treatments and finishes for wood

Answer 38

Wood can be protected and visually enhanced using:
• Preservative
• Wax
• Oil
• Paint
• Stain
• Varnish
• Finishes can be applied by brushing, rubbing
or spraying
• What treat

Question 39

Wood preservation

Answer 39

Treating timber can help extend its life for decades
• Tanalising is the process in which timber is
immersed in a preservative
• Hydraulic pressure forces the treatment deep into the timber
• Helps delay the rotting process
• Protects against insect and fungal attack

Question 40

Commercial finishing

Answer 40

Modern finishes can extend the life of
timber based products
• Products can be sprayed by hand or machine
• Patterns, logos or wording
can be printed onto the surface
• One of the fastest ways of
painting is using a
‘curtain coater’ which gives
a smooth and even coat

Question 41

Environmental impacts

Answer 41

Traditional paints and finishes can have harmful
effects on the environment
• Oil or solvent based products offer long lasting finishes, but
contain high levels of VOCs – Volatile Organic Compounds
• Water based products are kinder to the environment
• Paint can be made from recycled latex and even milk