DT GCSE Timbers (Section B)

Softwood

Softwood

Grow in cold climates

Fast growing

Cheap

Readily accessible

Needles and keep them in the winter (evergreen)

Pine

Strong and cheap

Used for telegraph poles, fences and cheap furniture.

Larch

Harder, tougher and more durable than other softwoods.

Resistant to rot - good for decking, cladding and fence posts.

Spruce

Not very durable and knotty

Hard and a good strength-to-weight ratio

Used for structural purposes - inside and out, Crates, ship masts

Hardwoods

Grow in warm climates

Slow growing

More expensive

Denser and harder - except Balsa!

Lose their leaves in the winter (deciduous)

Oak

Tough, durable and very strong

Attractive grain

Finishes well

Used for interior panelling, flooring and furniture

Corrodes steel screws and fittings

Mahogany

Red-brown colour

Durable and easy to work with

Expensive

Used for good quality furniture

Beech

Hard - resists dents

Can be bent using steam

Used for chairs and toys

Balsa

Very low density for a hardwood

Very soft

Easy to cut and shape

High strength to weight ratio

Great for modelling

Ash

Tough

Absorbs shock well

Used for tool handles and wooden sports equipment - Cricket bats

Attractive and also used for furniture

Manufactured Boards

Processed pieces of wood can be combined with glue and compressed into panels.

Available in large sheets - good for construction

Very stable - doesn't warp like natural timber

MDF

Medium density fibreboard

Tiny fibres of softwood held together with glue

No natural grain

Cheap, dense and takes finishes like paint very well

Used for shelves and flat-pack furniture

Plywood

Made up of several layers of softwood or hardwood

Grains at right angles to each other

Structure makes it very strong

Very popular board - used for building and furniture

Chipboard

Made by compressing wood chips and sawdust together with glue. \n Usually has a veneered surface \n Cheap but not very strong \n Absorbent and can be easily damaged by moisture \n Used in cheap self-assembly furniture

Air seasoning

Making a small shelter and stacking them. The air then dries the planks. This is a cheaper option compared to Kiln seasoning. It is slower than Kiln seasoning.

Kiln seasoning

Giant brick oven, put the planks in and it then heats them up to dry them. Is quicker but more expensive. Have to pay for heating and power and keep repairing it.

Forest stewardship council

Council that certifies that products are made with sustainable woods.

Carcase joints

They are easy to cut by machine as well as by hand. They are used for making boxes and box frames. In carcase construction, boards are joined end to end using dovetails, tongue-and-groove joints,

Stool joints

A stool formed of parts held together by pegged mortise-and-tenon joints : a stool made by a joiner.

Frame joints

Frame joints are mainly concerned with joining end to edge.

Surface treatments and finishes

Oil, paint, varnish, stain, wax, wood preservative, lamination.

Oil

It soaks into the timber. As it soaks through the wood it provides protection and some water resitance. It helps to replenish the wood's natural oils that are lost through age, exposure as well as wear and tear.

Paint

Applied with brush or roller. Usually needs an undercoat or primer when applied to bare wood. It gives a colour finish and gives the wood and layer of protection against weathering.

Stain

This permanently stains thw wood and the colour of the stain is affected by the base wood. However, this does not protect it.

Varnish

It is transparent and enhances the natural grain of the timber. It can be colour tinted with an oil stain and protects the wood from moisture. However, it tend to yellow overtime.

Wax

A thin layer is applied using a soft cloth or fine steel wool and pushed into the wood. It helps to enhance the natural colour and makes it shine. It helps to protect wood from moisture.

Wood preservative

This protects the wood from fungal or insect attacks. It helps to prevent rot and decay. However, it will need regular reapplication to keep up levels of protection.

Lamination

Plywood is a manufactured material. A number of thin layer. Veneers of wood are laid at right angles to each other. Then glued and heat pressed to create a strong material. Decorative laminate surface can be used to add a lasting protective layer or a nice finish.

MDF source to product

1. Cut down tree.

2. 2.Debark.

3. Sort into sizes.

4. Cut into manageable lengths e.g. Planks.

5. Collect saw dust/ wood chip waste for MDF, Chipboard, and plywood.

6. Clean and pulp sawdust.

7. The soft wood chips become wood fibres.

8. Mix with Urea Formaldehyde.

9. Press into sheets.

10. Dry, trim, sand.

Natural source to product

1. Cut down tree. 2.Debark.

2. Sort into sizes.

3. Cut into manageable lengths e.g. Planks.

4. Planks need to be dried (air seasoning/ kiln seasoning).

5. Pick stock form- rods, planks, veneers, wood chips.

Natural workable material to product

1. Pick suitable material and stock form.

2. CNC router.

3. Create and send desing to router.

4. Removes wood in thin later with rotating multi-tooth cutter.

5. Can be set to different speeds/ depths.

6. Add treatment/finishes e.g. Oil.

7. Assemble e.g. With stool joint.