Wood comes from two types of tree — the tree type decides the category, not how hard the wood is.

• Trees use tubes (xylem) to transport water up the tree — we call these fibres.
• From the side, the fibres show as dark lines — this is the grain.
• Wood is weak along the grain. (Classic exam question: "How will this break?" — answer: it splits along the grain, following the fibres.)
• You can count the dark rings on a tree to determine its age — these are age rings.
• The dark lines are denser and formed from slow growth during winter; light rings are fast summer growth.

Pine — Softwood

Cedar — Softwood

Redwood — Softwood

Spruce — Softwood

Mahogany — Hardwood

Oak — Hardwood

Beech — Hardwood

Jelutong — Hardwood

Meranti — Hardwood

Balsa — Hardwood

Manufactured board is a composite material made from wood particles, fibres and veneers bound together with adhesives to create a wood-like panel.

• Advantages: improved properties — directional strength, stable dimensions, cheaper, uniform, stable.
• Disadvantages: some are easily damaged or soak up water; some weigh more or cost more.

MDF (Medium Density Fibreboard)

• Wood particles and glue compressed together.
• Can't get wet — it swells.
• Very dense.
• Will flake apart (edges crumble).

Plywood

• Layers of ply with the grain glued together at 90 degrees each time — this removes the weakness (wood is weak along the grain, so alternate the direction).
• Different quality materials can be used (e.g. decorative outer veneer, cheap core).

Blockboard

• Strips of softwood in the core with a layer of ply on the top and bottom.
• Useful when you need thicker material without the weight/cost of solid wood.

Chipboard

• Large wood particles and glue compressed together.
• The cheapest wood product you can buy.
• Normally covered with laminate (e.g. flat-pack shelves).

• Reduces the water content to 10–20%.
• Stabilises the wood (stops warping/twisting/shrinking after you build with it).
• Kills fungus and insects.

• Planks can only be as big as the tree allows — so you glue multiple planks together to make a board.
• Sash clamps are used to glue large pieces together.
• Natural woods bend and twist — when you glue planks into a board, the bending could multiply.
• So you glue the curve of the grain in alternating directions — each plank's twist cancels the next one out.

• Mark out on all sides — keeps cutting accurate and square (you can see the line from every direction).
• Shade out waste material (scribble over it) — shows exactly where to cut and stops you cutting the wrong piece.
• Marking knives are used for precision — the knife line also creates a track for saws and chisels, and prevents wood splitting beyond the line.

A board's working face and working edge are the two reference surfaces that all measurements are taken from.

• This dates back to when boards were planed by hand — you couldn't rely on every side being parallel, so two surfaces were designated as reference surfaces.
• It's still a good idea today. The marks can also mean front and top.
• Everything is measured from the working face/edge, so a mistake never propagates from an uneven surface.

Teacher instruction: Mark out a finger joint on the wood (x / ¼y / y dimensions on the side profile).

1. Mark all the way around the wood — this helps when you cut it out.
2. Scribble the waste material — prevents cutting the wrong piece.
3. Transfer the profile from the end face down both sides so saw cuts line up.

Saws are used to remove the bulk of the material close to shape — then a metal file, sandpaper or planes give the final shape and finish.

Steaming (bending)

• Problem: cutting a curved shape out of a solid board wastes material and is weak across the grain.
• Steaming softens the resin in the wood, which allows it to be bent while soft.
• Steam chamber: wood is left in hot steam until the resin softens, then bent around a former/jig and left to set.

Laminating

• Thin/flexible pieces of wood are glued together and held in shape; when the glue sets, it stays in that shape.
• Vacuum bag — uses air pressure to hold the laminate in shape.
• A jig — uses clamps to hold it in shape.

Teacher instruction: Choose one of these products. Create a blue foam former and laminate using the bagpress.

1. Choose your product design (organiser).
2. Create a blue foam former — the foam is shaped to the curve you want, then the flexible plywood is pressed over/into it.
3. Laminate using the bagpress (vacuum bag) — air pressure holds the plies tight to the former.
4. Remember: flexible plywood will only bend to a maximum radius before breaking — design your former curve within the limit.
5. Finish the edge of the product using a jack plane.

The class deck shows photo grids of joints. Learn to recognise each one by shape:

The deck sets up this exact exam-style question:

Knock-down fittings are hardware components designed to join panels together temporarily or permanently without traditional wood glue and clamps.

They're heavily used in flat-pack furniture (e.g. IKEA) — manufactured quickly, shipped flat, assembled at home with basic tools like a screwdriver or Allen key.

FPT — Knock-down fittings (pairs)

Teacher instruction: In pairs, using scrap wood, make the drilling jigs and construct a scan fitting.

1. Question to solve first: how would you make a drilling jig to drill these holes? — a jig guarantees the same hole positions on every identical piece.
2. Make the drilling jig from scrap wood.
3. Drill the holes and assemble the scan fitting.

FPT — Screws and Nails (paired activity)

Teacher instruction: Follow the steps to create a countersunk screw joint. Then, using 4 nails, try dovetail nailing.

1. Mark and drill pilot + clearance + countersink holes.
2. Drive the countersunk screw flush.
3. Practice dovetail nailing: 4 nails, angled so they lock.

Finishes protect the wood (moisture, scratches, insects) and improve appearance. Common finish types:

Photo of a wood sample + "Name this wood. Give two properties and one use." (4 marks)

1. Appearance clues: colour (yellowish = pine, red-brown = cedar/mahogany, pale white = jelutong/balsa) + grain (long thick = softwoods, swirly = oak, ribbon stripe = meranti, freckles = beech).
2. Category: say softwood or hardwood too — often a mark.
3. Properties: quote the deck table (density, durability, workability, water resistance).
4. Use: connect to properties — e.g. cedar repels insects → clothing storage.

"Score each joint for aesthetics, surface area, mechanical strength and difficulty to construct. Justify one of your scores."

1. Fill the table fast using your benchmarks (Joining tab).
2. Justification = property → consequence: "Finger joint has a large surface area, so the glue bond is strong."
3. Relate to use: "A dovetail can't be pulled apart, so it suits drawers."

FPTs are the timed practicals: finger joint, laminated organiser, KD fitting + drilling jig, screws & nails. Marks come from process, not the finished look.

• ✗ Saying hardwood = hard. Tree type decides the category.
• ✗ Mixing pilot vs clearance hole diameters.
• ✗ "Describe" answers written as "Explain" (no because).
• ✗ Forgetting wood is weak along the grain in break/strength questions.
• ✗ Naming MDF for outdoor use — it can't get wet.
• ✗ Writing "glue" instead of a named adhesive with its properties.
• ✗ No justification in the joint scoring table.