Wood

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Wood
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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.
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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 theyre usually cheaper than hardwoods.

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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

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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 woods grain. Its available in
  natural but also in bright colours. Stains
  usually dont protect the wood, so varnish may
  need to be applied afterwards.

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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 dont protect wood from water.
• Polyurethane paint is more expensive but is
  waterproof and much tougher.

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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.
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Manufactured Boards
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Plywood

• Important properties very strong, doesnt 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 its 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. Thats the reason why it is very strong.

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Hardboard

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

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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

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Chipboard

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

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Solid Timber
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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

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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

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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

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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