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
a
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 firj
Decking
Furniture
Beams
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
