3.1 Stock Forms of Wood Flashcards
What are the stock forms Natural timbers are available in?
- Rough sawn
- Planed square edge (PSE)
- Planed all round (PAR)
What is rough sawn?
- This is the most basic and cost effective form of wood preparation after the felling of the tree. It is not planed, but is left with a rough surface.
- Commonly used in construction and fence-posts
How is planed timber prepared?
using a planer and thicknesser
What is the difference between PSE and PAR planed timber?
- PSE is only planed on 2 sides - only has one square edge
- PAR is planed on all sides - it’s square on all sides
What are mouldings?
machined profiles made for functional and aesthetic purposes
What are the measurements of full boards?
1220 x 2440mm
What are manufactured boards?
They are produced by gluing wood layers or wood fibres together
What type of trees does softwood come from?
Coniferous trees
What type of trees does hardwood come from?
Deciduous trees
Name the most common softwoods
- Pine
- Douglas fir
- Cedar
- Spruce
- Redwood
- Larch
What are the properties of Pine?
- It’s lightweight with a straight grain but has knots
- It’s easy to work with, glues and finishes well and it’s cost-effective
- It can be used outdoors but must be treated or protected first
- Used in furniture and wooden flooring
What are the properties of Redwood?
- The tallest trees in the world
- Lightweight, soft, good strength-to-weigh ratio
- Used for construction, decking and musical instruments
What are the properties of Spruce?
- It’s easy to work with and has a uniform texture
- It was widely used in the construction of aircraft in World War I and II and is now used in housing construction, cabinets and instruments
What are the properties of Cedar?
- It’s resistant to decay, moisture, weathering and insect attack as it has a high oil content
- Lightweight, easy to work with and knot free but is fairly toxic
- Used for boat building and outdoor panelling
What are the properties of Larch?
- It’s a hard timber with a reddish brown colour which fades to grey when exposed to sunlight
- It has a high resin content which can clog up cutting blades
- Used for veneers as well as fence posts, garden furniture and boats
What are the properties of Douglas fir?
- It’s cheap, stable (holds its shape as it swells and shrinks) and one of the toughest woods
- Can be difficult to treat due to its density and high resin content
- It’s suitable for large-scale projects such as housing frameworks and cladding
Name the most common hardwoods
- Oak
- Ash
- Mahogany
- Teak
- Birch
- Beech
What are the properties of oak?
- It’s tough, durable and hardwearing
- It’s resistant to rot when exposed to moisture
- It contains tannic acid which corrodes steel
- For hundreds of years, oak was the main engineering material for shipbuilding and architecture
What are the properties of Ash?
- It’s a very springy hardwood with large open pores which gives it elastic qualities
- This makes it shock resistant, so it’s often used in sports equipment and tool handles
What are the properties of Mohagony?
- It’s a highly-prized timber with excellent stability, workability and a beautiful grain
What are the properties of Teak?
- It’s naturally high in oils
- Considered the best in terms of decay resistance and durability, but it’s toxic
- It also has a high resistance to acids and alkalis
- It’s ideal for outdoor products including furniture and boats
What is Birch?
- It’s a low-cost hardwood and has a fine grain which gives a uniform, even texture and it’s easy to work with
- It’s one of the least resilient timbers in terms of insect attack and its resistance to rot
- Used for plywood, boxes, paper pulp and ideal for veneers
What are the properties of Beech?
- It’s hard, tough and odourless so it is resistant to abrasion and does not affect the taste of food
- It has a close, straight grain which makes it easy to work with
- It’s flexible and ideal for steam-bending
Name some of the Manufactured boards
- Plywood
- Marine plywood
- Aeroply
- Flexible plywood
- Chipboard
- MDF
What is plywood?
- It has good strength in all directions, no grain weakness
- Uses lower-grade hardwood and softwood veneers
- Used for floorboards and indoor furniture
What is marine plywood?
- similar construction to plywood but is patch-free and knot-free
- A waterproof adhesive is used so it can withstand use in wet conditions
- Used for boats
What is Aeroply?
- Plywood made from high-quality timbers such as beech
- Available in very thin sheets, lightweight and easy to bend around a support frame
- Used to laminate furniture
What is flexible plywood?
- An odd number of layers glued together with the two outer layers made from open-grained timber which allows the sheet to flex.
- Used for laminated furniture and curved panels
What is Chipboard?
- Wood chips compressed with a resin
- Often veneered or covered with polymer laminate, kitchen worktops and units, shelving etc.
What is MDF?
- It’s compressed wood fibres (sometimes with an added resin) and it has two smooth faces
- Used for model-making or mould making and furniture items
What are wood veneers?
They are thin slices of wood less than 3mm thick
