Wood

Woods can be divided into two main categories – softwood and hardwood. This is not a description of the wood – it just means what type of tree it comes from.

Softwood: Most softwood trees are coniferous (cone bearing). They typically have thin, needle- like leaves and are evergreen (pine, cedar, yew). They grow in colder climates and are fast growing- most reaching maturity within 30 years. This makes them easy to replace with new trees, so they’re usually cheaper than hardwoods.

Hardwood: Most hardwood trees are broadleaved and deciduous (they shed their leaves annually). For example: Oak, Mahogany, Beech, Elm, Broadleaf trees grow in warm climates and are usually slow growing. They can take around a hundred years to mature, so there are more expensive than softwoods. Colours are: Oak- rich light brown Mahogany- reddish brown Beech- creamy/ pinkish Elm- light reddish brown

Protection: Polyurethane varnish can be used to seal and protect the surface of the wood, and give it a smooth surface finish. You can buy it clear or in a wide range of colours. Woodstain can be applied to wood to enhance the appearance of the wood’s grain. It’s available in natural but also in bright colours. Stains usually don’t protect the wood, so varnish may need to be applied afterwards.

Protection: Oil can be used to maintain a natural appearance of the wood. Some oil- based finishes also offer protection to wood used outdoors. Paint is often used to colour and protect wood. Emulsion paints are cheap, but they are water- based, so they don’t protect wood from water. Polyurethane paint is more expensive but is waterproof and much tougher.

Solid woods are cut straight from the tree Solid woods are cut straight from the tree. Man- made woods (boards) are made from the bits of waste that are produced when the trunks and branches are cut into planks.

Manufactured Boards:

Plywood: Important properties: very strong, doesn’t warp, exterior plywood is water resistant. Making tips: can split when cut, outside of the board can be finished with a nice veneer (thin layer of good quality wood). Typical uses: containers, flat cut- out figures, mechanical parts, wheels In general: it’s made up of several layers (always an odd number of them) and the layers are glued with their grain at 90 degrees to each other. That’s the reason why it is very strong.

Hardboard: Important properties: brittle, goes soggy with water Making things: tears easily, difficult to finish edges Typical uses: covering panels

Medium Density Fibreboard (MDF): Important properties: hard, keeps edges well, goes soggy with water, has smooth faces and takes paint and other finishes well Making tips: blunts tools, shapes easily, finishes well, drills well Typical uses: block models, vacuum forming moulds, small bases

Chipboard: Important properties: brittle, edges easily damaged Making tips: difficult to shape, blunts tools, finishes poorly, catches on drills Typical uses: large bases; because it’s cheap but not very strong, so is usually used with a hardwood or plastic veneered surface in cheap furniture

Solid Timber:

Red Deal (Pine): Important properties: softwood, cream and pale brown colour, often knotty, rots unless protected Making tips: easy to cut, trim, shape and join Cost: low Typical uses: simple frameworks, block models

Mahogany: Important properties: hardwood, red- brown colour, durable Making tips: more difficult to work than red deal Cost: medium Typical uses: containers, indoor furniture, items requiring decorative finish

Balsa: Important properties: hardwood, whitish pink, very soft, very light, not durable Making tips: very easy to shape, cut and trim for joining use balsa cement Cost: high Typical uses: rapid model- making, light weight structures

Jelutong: Important properties: hardwood, light colour, no knots, more durable than red deal Making tips: easy to cut, trim, shape and join Cost: medium Typical uses: simple frameworks, block models, moulds for vacuum forming