Timbers Flashcards
What is a hardwood tree?
a tree that grows slowly and in warmer climates
What is a softwood tree?
a tree that grows fast and in cooler climates
What is a coniferous tree?
a tree that is evergreen, cone shaped and has needle like leaves
What is a deciduous tree?
a tree that looses its leaves usually in autumn
Name 7 hardwoods?
ash
beech
mahogany
oak
balsa
Birch
Teak
Properties of ash?
tough, absorbs well, flexible, wide grained, finishes well
Uses of ash?
sports equipment, ladders
Key property of beech?
can be bent using steam
Uses of beech?
Chairs and toys
Properties of mahogany?
strong and durable
available in wide planks
fairly easy to work
Uses of mahogany?
good quality furniture
Properties of oak?
hard, tough, durable, open grain, high standard finish
Uses of oak?
timber framed buildings, flooring, high quality furniture
Properties of balsa?
-High strength-to weight-ratio
-Soft
-Low density
Uses of balsa?
model making, floats, rafts
Name 5 softwoods?
larch, pine, spruce, cedar, Douglas fir
Properties of larch?
harder, tougher and more durable than most softwoods. Resistant to rot.
Uses of larch?
fencing, fence posts, decking
Properties of pine?
Strong, knotty-makes it harder to work with.
Uses of pine?
-interior joinery
-cheap furniture
-window frames
-telegraph poles
Properties of spruce?
hard, lightweight, easy to work with small knots and good resonant properties
Uses of spruce?
bedroom furniture and stringed instruments
What are the two categories for manufactured boards?
laminated boards and compressed boards
What are laminated boards?
large sheets or veneers glued together
What is a compressed board?
Particles, chips or flakes of wood glued together under pressure.
What are some advantages of manufactured boards?
- large sheets
- consistent throughout
- more stable than timber
- make use of low grade timber-environmental benefits
Give five examples of manufactured boards?
MDF, plywood, chipboard, marine plywood, aeroply, flexible plywood
Properties of MDF?
smooth surface, compressed fibres of wood combined with a synthetic adhesive, porous-can be damaged by moisture
Uses of MDF?
Shelves and flat-pack furniture
Properties of Plywood?
Several layers of softwood or hardwood glued together with their grains at right angles to one another, very strong, hard to bend.
Uses of Plywood?
building and furniture
Properties of chipboard?
made by compressing wood chips, shavings and sawdust together with glue usually with a veneered surface. Not very strong, absorbent-easily damaged by moisture.
Uses of Chipboard?
cheap self-assembly furniture
Properties of Douglas Fir?
Good corrosion resistance
Few knots
Uses of Douglas fir?
Joinery
Construction work
Veneers
Properties of Cedar?
Good sound damping
Good moisture resistance
Hard and tough
Uses of cedar?
Cladding, decking, fencing
Properties of teak?
Natural oils which resist moisture, acids and alkalis
Uses of teak?
Outdoor furniture
Properties of birch?
Resists warping
Hard
Uses of birch?
Furniture
Veneers for plywood
What is marine plywood and what are its uses?
A special type of plywood with no gaps and uses water resistant glue. Used in boat panelling and dashboards
What is aeroply and what are its uses?
Plywood made from higher quality timber (such as birch)
Used in laminated furniture
What is flexible plywood and what are its uses?
Two outer layers are made from open grain timber, allowing flex. Used for curved panels
What are the two types of seasoning?
Air and Kiln
Explain air seasoning
-The wood is stacked under a shelter, protected from rain
-Air circulates between the planks to slowly remove excess moisture
-Used for outdoor products as it’s seasoned to match the humidity of the surroundings
Explain kiln seasoning
-Planks are stacked and placed in a kiln
-The kiln atmosphere is changed to become hotter and drier to draw out the moisture
-Wood has a lower moisture content so is used for interior products
What are the advantages of seasoning?
Greater resistance to rot and decay
Increased strength and stability
Makes wood less corrosive to metals
What is dry rot?
Caused by incorrect seasoning or poor building maintenance
What are the advantages and disadvantages of kiln seasoning compared to air?
-Quicker
-Moisture can be controlled better
-More expensive
-Ideal for interior use wood
What is rough sawn stock form?
The wood comes directly from seasoning and has rough surfaces produced during initial conversion
What is planned square edge stock form?
Edges are not rounded in any way. PSE has each edge planned perfectly straight
What is planned all round stock form?
PAR wood has sides and edges that are all planned straight and level
