B. Timbers Flashcards
What is hardwood?
Hardwood is from a deciduous tree, usually a broad-leafed variety.
What are the properties and uses of Ash?
Hardwood
Properties: Flexible, tough and shock resistant, laminates well
Colour: Pale brown
Uses: Sports equipment and tool handles
What are the properties and uses of Mahogany?
Hardwood
Properties: Easily worked, durable and finishes well
Colour: Reddish brown
Uses: Flooring, furniture and joinery, veneers
What are the properties and uses of Oak?
Hardwood
Properties: Tough, hard and durable, high quality finish
Colour: Light brown
Uses: Flooring, furniture, railway sleepers, veneers
What are the properties and uses of Beech?
Hardwood
Properties: Fine finish, tough and durable
Colour: Beige with pink hue
Uses: Children’s toys and models, furniture, veneers
What are the properties and uses of Balsa?
Hardwood
Properties: Soft and spongy, good strength to weight ratio
Colour: Pale cream/white
Uses: Prototyping and modelling
What is a softwood?
Softwood is from a coniferous tree that usually bears needles and has cones
What are the properties and uses of Pine?
Softwood
Properties: Lightweight, easy to work, can split and be resinous near knots
Colour: Pale yellowish brown
Uses: Interior construction, furniture
What are the properties and uses of Spruce?
Softwood
Properties: Easy to work, high stiffness to weight ratio
Colour: Creamy white
Uses: Construction, furniture, musical instruments
What are the properties and uses of Larch?
Softwood
Properties: Durable, tough, good water resistance, good surface finish
Colour: Pale reddish brown
Uses: Exterior cladding, decking, flooring, machine mouldings, furniture and joinery, railway sleepers, veneers
What are manufactured timbers?
Sheets of processed timber waste products. They are made from waste wood, low grade timber and recycled timber
What are the properties and uses of Chipboard?
Manufactured timber
Properties: Good comprehensive strength, not water resistant unless treated, good value but prone to chipping on edges
Uses: Flooring, low-end furniture, kitchen units, worktops
What are the properties and uses of Medium Density Fibreboard (MDF)?
Manufactured timber
Properties: Rigid and stable, smooth and easy to finish surface. Absorbent, so not goof in high humidity
Uses: Good value, flatpack furniture, toys, kitchen units and internal construction
What are the properties and uses of Plywood?
Manufactured timber
Properties: Stable in all directions due to alternating layers at 90 (outside layers run in the same direction)
Uses: Furniture, shelving, toys and construction. Interior, exterior and marine grades available
Advantages of using manufactured timber over natural timber
- Available in large board sizes which can reduce the number of joints
- Cheaper than natural timber
- A good insulator
- Easily cut
- Easily laminated to apply a wide range of finishes
Disadvantages of using manufactured timber over natural timber
- Dense, making it very heavy in large sheets
- Due to its density and the adhesive used in production, it can quickly blunt blades
- Resins and binders used can be toxic
- Edges are difficult to finish due to no natural grain
Why does newly cut timber need to be seasoned?
Green timber contains a lot of moisture. In order to reduce the moisture content, it needs to be seasoned
How does air seasoning work?
Air dried timber is separated and stacked under a protective roofed structure, with open sides so that the air can circulate.
How does kiln seasoning work?
The kiln is filled with steam and, and the moisture content is gradually reduced to dry out the wood. Expensive, but enables timber to be sold more quickly
How is MDF produced?
Waste wood is broken down into fibres and combined with a resin binder. It is then pressed into sheets that are dense and strong
How is Plywood produced?
Thin layers (veneers) of wood are glued together. Each layer has its wood grain rotated at 90.
How is Chipboard produced?
Wood chips of varying sizes are mixed with resin, pressed and formed into a sheet
How can softwoods and manufactured boards be made to look like more expensive hardwoods?
- Boards could be laminated with a thin veneer of hardwood on the outer surface
- Boards could be laminated with Formia (melanin formaldehyde)
- Boards could be stained
Which timber is best for flat-packed furniture?
Manufactured boards
- More consistent than natural wood due to lack of knots or grain
Which timber is best for children’s toys?
Beech or oak
- Dense grain and can be sanded to a smooth surface, so there are no splinters
Which timber would be best for constructing a garden shed?
Larch
- Tough
- Durable
- Water resistant due to natural oil content
How to join two pieces of wood together using wood screws
Need a hole to be pre-drilled through both pieces of wood
- This hole (pilot hole) needs to be narrower than the diameter of the screw
Why are knock down fittings suitable for kitchen cabinets?
- KD fittings can be easily assembled with a simple selection of tools.
- They provide a strong enough joint and are lightweight
- Can be taken down without damaging the item
What is lamination?
Gluing or heat pressing several layers of wood to create a strong composite
Where is lamination used?
Laminated floor materials, office furniture and kitchen units
What is glulam?
Strips of wood are layered together with a strong adhesive. The grain runs along the length of the timber
What is glulam used for?
Glulam is a strong timber used for load bearing structures such as bridges and beams
What is an oil finish?
- Soaks into the timber
- Replenishes natural oils that has been lost through exposure, age and wear and tear
- Provides protection and some water resistance
What is a paint finish?
- Gives a colour finish and adds a layer of protection against weathering
- Needs a primer on bare wood
What is a varnish finish?
- Transparent and enhances the natural grain of the timber
- Protects from moisture
- Can be colour tinted with oil stain; yellows over time
What is a wax finish?
- Protects from moisture
- Enhances natural colour and gives it a deep shine
- Applied with steel wool
What is a wood preservative?
Protects wood from fungal or insect attack. Helps prevent rot and decay.
Needs regular application to maintain protection
What is a wood stain?
- Permanently stains wood; can be affected by base wood
- Does not protect
What is tantalisation for?
To provide long-term protection against rot, fungal and insect attack
Where is tantalisation used?
Tantalised timber is used for outdoor applications to extend its life - usually for fencing, decking, walkways and footbridges
What is tantalisation?
The timber is pressure impregnated with wood preservative.
Why does timber need to be protected with an additional treatment and wood finish?
- Can prevent rot and reduce the chance of a fungal or insect attack
- Have a surface treatment to protect from wear and tear
