1.6 Performance Characteristics of Woods Flashcards
Describe rough sawn
Wood that comes direct from seasoning and has rough surfaces produced during initial conversion
Has nominal sizes rather than accurate finished sizes and is the cheapest stock form
Describe planed square edge (PSE)
Wood only has one edge that is planed accurately; the rest are rough sawn
Planing removes about 3mm from the original nominal size
Example
Original size: 25mm x 50mm
Planed size: 22mm x 47mm
Describe planed all round (PAR)
Wood has sides and edges that are all planed square, straight and level, leaving a smooth finish
About 3mm smaller all round than the original rough-sawn and most expensive
Example
Original size: 25mm x 50mm
Planed size: 19mm x 44mm
State the three types of woods
- Natural wood
- Manufactured boards
- Mouldings
Describe natural wood
Only available at the maximum width of the tree
To produce wider, planks need to be joined together
Planks should be joined with the end grain going in different directions to avoid distortion
Describe manufactured boards and give standard sizes
Man-made and produced in large sheets typically 1220x2440
Wide surfaces can be joined without the need for joining processes
Describe mouldings
Premade such as skirting boards or wooden trims available in standard lengths
Give four facts about air seasoning
- Wood is stacked in a shelter outside, protected from the rain
- Air circulates between planks to remove excess moisture
- Slow, up to one year, and inexpensive
- Used for outdoor products
Give four facts about kiln seasoning
- Wood is stacked on trolleys
- Kiln dried
- Quick, only a few weeks & cheap
- Used for indoor products
Why is wood seasoned?
- gives greater immunity from decay and increased resistance to rot
- Increases strength and stability
- Helps preservatives to penetrate
- Makes wood less corrosive to metals
Define hardwood and give three examples
A wood from broadleaved (deciduous) trees.
- Oak
- Ash
- Mahogany
- Teak
- Birch
- Beech
State three properties/characteristics of oak
- Tough
- Hard
- Durable
- Good weather resistance
- Contains tannic acid, which will corrode steel screws or fixings
State two uses of oak
- Furniture
- Flooring
- Construction, boat building, and carpentry
State three properties/characteristics of ash
- Tough
- Open grained
- Flexible
- Can be bend if streamed
State two uses of ash
- Tool handles
- Laminates
- Sport equipment
State three properties/characteristics of mahogany
- Durable
- Interlocking grains (which could make it difficult to work)
- Excellent for carving
- Finishes well
State two uses of mahogany
- Outdoor furniture
- Good quality furniture
- Veneers
State three properties/characteristics of teak
- Tough
- Hard
- Straight grains
- Natural oils (resist to moisture, acids, and alkalis)
State two uses of teak
- Outdoor furniture
- Traditional boat decks
State three properties/characteristics of birch
- Hard
- Straight close-grained
- Resists warping
State two uses of birch
- Furniture
- Veneers
- Indoor paneling
State three properties/characteristics of beech
- Tough
- Hard
- Close grained
State two uses of beech
- Furniture
- Toys
- Kitchen utensils
- Tools handle
Define softwood and give three examples
Wood from a coniferous tree
- Pine
- Spruce
- Douglas fir
- Larch
- Cedar
State three properties/characteristics of pine
- Easy to work with
- Relatively cheap
- May contain knots that will weaken the wood
- Straight grains
State two uses of pine
- Building frames and construction
- Furniture (needs protection if used outside)
- Window frames, roofing, floors, and paneling
State three properties/characteristics of spruce
- Straight grains
- Resistance to splitting
- Easy to saw
State two uses of spruce
- Factory flooring and building/construction
- Indoor furniture
State three properties/characteristics of Douglas fir
- Good resistance to corrosion
- Straight or slightly wavy grain
- Few knots
- Stable
State two uses of Douglas fir
- Building and construction
- Balconies, stairs, flooring, wall paneling
- Veneers
State three properties/characteristics of larch
- Tough
- Hard
- Attractive grain pattern
- Fades to silver (grey) upon exposure outside (sunlight)
State two uses of larch
- Garden furniture
- Fencing
- Cladding decking
State three properties/characteristics of cedar
- Straight grain
- Can corrode ferrous metals due to their acidic nature
- Low density
- Insect resistant
State two uses of cedar
- Sheds, greenhouses, beehives
- Exterior cladding
- Interior paneling
Define manufactured boards and give three examples
A man-made wood-based composite material
- Plywood
- Marine plywood
- Aeroply
- Flexible plywood
- Chipboard
- MDF
State three properties/characteristics of plywood
- Strong in every direction
- No grain weakness
- Always has an odd number of layers
State two uses of plywood
- Structural work
- Desktops
- Indoor furniture
- Floorboards
State three properties/characteristics of marine plywood
- Similar construction to plywood
- Moisture resistance
- Resistant to fungal attack
- Quite expensive
State two uses of marine plywood
- Boat dashboards
- Boat lockers
- Panelling
State three properties/characteristics of aeroply
- Plywood made from high quality timber, such as birch
- Available in very thin sheets
- Lightweight
- Easy to bend around a support frame
State two uses of aeroply
- Gliders
- Laminated furniture
- Laser cut projects
- Jewellery items
State one property/characteristic of flexible plywood
- two outer layers made from open-grained timber, which allows the sheet to flex
State two uses of flexible plywood
- Laminated furniture
- Curved panels
State two properties/characteristics of chipboard
- Made from wood chips bonded with resin under pressure
- Not very resilient without surface treatment
- Durability is improved with veneers or a hard-wearing paint
State two uses of chipboard
- Often veneered or covered with a polymer laminate
- Kitchen worktops and units
- Shelving and ‘flat pack’ furniture
State two properties/characteristics of MDF
- Made from fine wood dust particles bonded with resin under pressure
- Not very resilient without surface treatment
- Durability is improved with veneers or a hard-wearing paint
State two uses of MDF
- Model/mould making
- Furniture items such as bookcases, cabinets and desks
