Specific topic 7.7 Timber (tools/equipment/processes)

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• There is a variety of useful hand tools for marking out, cutting and shaping wood. Tools for marking out accurately are important. If you mark out your work accurately you can cut it accurately too. A try square is used to mark a line at 90° to an edge and check if something is square – versatile, may be damaged if dropped A marking gauge used to mark a line parallel to an edge – can mark out several pieces of timber at the same measurement, the scribing point (spur) scratches the timber so it is vital the gauge is set correctly

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• The first woodworkers had to do everything with hand tools, which could be quite time consuming. Nowadays we have a lot of electrically operated machinery that makes woodwork much quicker and easier. The circular saw and bandsaw in Section 7.6 on page 292 are very useful machines for cutting timber to the required size. A pillar drill: in a workshop work is held flat on the table and the drill makes accurate 90° vertical holes. It requires various clamping methods depending on the shape and thickness of the material to be drilled A hand-held ‘cordless’ battery-operated drill is very useful on site or for big pieces of work that are hard to move – no power lead so it can work away from a power source, but requires a charged battery to work

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• Computer-aided design software is useful for drawing parts of a product accurately. It is essential if the work is going to be cut out with computer-aided manufacture, as the computer sends information from the drawing to the machine, such as a CNC router or a laser cutter. The big advantage of computeraided design and manufacture is the speed and accuracy with which it can cut.

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• A drill makes a round hole in material. There are different types which all have their advantages and disadvantages.

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• Timber is cut with a saw. A saw has teeth on it that cut the wood as the saw is pushed over the wood. There are different types of saw, but they all use the same principle.

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• A plane has a sharp blade, which must be kept sharp, protruding from a flat base plate. It is used to remove wood from the edge of a piece of timber, and is good for getting a crooked edge straight. Planes are available in different lengths and it is easy to adjust depth of cut. A planer/thicknesser is a useful machine for preparing timber. A rotating cutter block planes the wood. The top of the table planes it to get flat, square faces and edges. Under the table the thicknesser draws the wood in and planes it to the set thickness.

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• A wood chisel is used for paring wood, that is, slicing between the grains. A mortise chisel has a much thicker blade and a heavier duty handle. It is used for cutting slots in wood, so it is hammered with a mallet a lot. Chisels are hard to use across end grain. A sharp chisel is easier and safer to use.

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• A wood-turning lathe holds a piece of wood and spins it. The operator holds a chisel on a rest and guides it over the spinning wood to chisel wood away. It requires careful preparation of material and setting up of the lathe.

1. Face plate
2. Between centres

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• Abrasive paper has a rough grit bonded on a paper or cloth backing. The first abrasive used was sand, hence the name sandpaper. Glass grit is more commonly used now. Abrasive paper is measured by the number of pieces of grit in a square inch, so the bigger the number the smaller the grit. P80 is a coarse grit that is good for the initial removal of material on a rough surface. P120 gets a smoother finish, and P240 gets a really smooth finish on wood. You can get finer grits, but there is little need for them when working with wood. When sanding wood, it is best to sand in line with the grain. Going across the grain can tear the grains and leave it rougher.

1. Glass pape

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• Ironmongery is a name for a range of parts that can be bought to go onto products. Items include: • hinges • handles • knobs • hooks • drawer runners • locks.

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• Butt hinge Used to fit doors Hidden from sight when door is closed Hard to fit as an accurate slot needs to be cut on both sides Flush hinge Used for small cupboard doors Easy to fit as no slots to cut Leaves a gap between the door and frame Butterfly hinge Screws onto the surface, often a decorative shape Easy to fit, as it screws onto the surface with the parts lined up The whole hinge shows on the surface T hinge Used for gates and shed doors Long bar good for supporting the weight of a gate Sits on the surface, so shows on the front of the gate or door

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• Knock-down fittings are a useful range of blocks and fittings that are easy to use to fix the pieces of a product together. They are used a lot for flat-pack furniture and cupboards because they are easy for the customer to fit themselves.

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• Laminating is joining layers together. Plywood is laminated, it is layers of veneer glued together. Laminate flooring is made up of layers. Laminating is useful in the workshop because thin layers can be bent and glued together, and they stay in the bent shape when the glue has dried. The bag press on page 293 is helpful for this.

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• Addition processes add pieces of material together. Assembling parts, by making joints, gluing, screwing and nailing pieces together are addition processes. This is a fast method of producing 3D shapes but often requires a range of joining techniques, which may be time consuming.

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• Veneer is a thin layer of wood, which means it can be more prone to damage. Plywood is made of layers of veneer laminated together. Veneer can be glued onto the surface of a cheaper material, such as MDF, to make the surface look like more expensive wood. MDF can be bought covered with hardwood veneer.

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• Wastage processes cut material away and waste it. This is usually the fastest way to obtain the required shape with sheet materials. Most woodworking processes are wastage processes: sawing, planing, filing and sanding all remove material that is wasted and leave the required shape behind. Waste can be minimised by careful planning and use of stock sizes or off-cuts. Waste material adds to the cost of the product so should be reused wherever possible.

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• Screws are a very useful fixing for joining pieces of wood together. They create a tight fit to make a strong joint, and they can be unscrewed and removed if necessary. There are two main head designs: slotted (also known as flat) and Phillips (a cross shape). You need the right screwdriver tip to fit the screw head. A countersunk screw is useful in wood, because you can make the head of the screw fit flat with the surface of the wood. A clearance hole must be drilled first to accommodate the screw head. Drilling a pilot hole as well, which must be narrower than the screw thread, will make it easier for the screw to go in.

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• Nails come in a range of shapes and sizes. Nails are hammered into the wood grain, which pinches tight onto them so they are hard to pull out. It is quick and nails can be driven below the surface and covered over to improve appearance. However, holes may need to be drilled to prevent wood from splitting. • Round wire nails usually have a large flat head so they do not pull through thin materials. • Oval nails spread the grain less, so are less likely to split the wood when hammered in. • Panel pins are small nails for small workpieces and for holding thin boards onto timber.

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• PVA (polyvinyl acetate) is a commonly used wood glue. It is a thick white liquid, but becomes clear when it dries. It makes a strong joint in wood as long as the pieces are clamped tightly together while the glue dries. It is almost impossible to disassemble a joint without destroying it when PVA has set.

1. PVA

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   • PVA (polyvinyl acetate) is a commonly used wood glue. It is a thick white liquid, but becomes clear when it dries. It makes a strong joint in wood as long as the pieces are clamped tightly together while the glue dries. It is almost impossible to disassemble a joint without destroying it when PVA has set.
2. Contact ahesive

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   • Contact adhesive is good for sticking a flat piece of a different material onto wood. Spread a thin film onto both surfaces, wait until it is nearly dry, then press the two parts firmly together. It is fast but there is little or no opportunity to reposition the pieces and it gives off solvent fumes.

1. Butt, dowel, lap,housing, mitre,mortise and tenon, dovetail