There are several point to bear in mind when considering timber selection : what is the piece you are making and how will it fit into the home? What final effect do you wish to achive? Are colour and grain pattern important factors, and so on. You wish to achieve? Are colour and rain pattern important factors, and so on You also need to see what is available from your timber supplier, so you can buy boards that allow you to cut components economically and use wood of suitable stability for the task. A cutting list helps when planning both the selection and preparation of the timber for any project, showing timber sizes andpreparation of the timber for any project, showing timber size and quantities.
The Cutting List
In the excitement of starting a new project it always pays to remember that you can save a great deal of time and money by planning what you are going to do before buying any timber. Make up a list of all the components you require for the project, stating against each item its length, width and thickness. (It may also help to have separate columns for sawn sizes as well as finished dimensions.)
This ‘cutting list’ is a great help when buying and selecting timber. It is also necessary when machining components back in the workshop, as you can see at a glance, both the rough-sawn size of an item and the finished dimensions after planing.
A good maxim is to design your components so that they can be planed easily from 25 mm (1 in) or 51 mm (2 in) rough boards. It is common practice for timber Yards to saw wood to about 28 mm (1 3/32 in), which dries down and shrinks to slightly over 25 mm (1 in). A board of this thickness will give you a finished component of roughly 19 mm (¾ in) when planed on both sides. A 51 mm (2 in) board will give a finished thickness of about 45 mm (1 ¾ in).
Consider carefully whether you need particularly stable components, such as drawer sides or the loose leaf for a drop-leaf table. In both these cases you should use quartersawn timber, which is particularly stable and less likely to cup or warp. Consider, also, whether you are buying kiln-dried or air-dried timber. If air-dried, then you must allow a period of at least one to two weeks after your initial planing of the timber for the material to settle and acclimatize to your workshop’s humidity. If you are using kiln-dried timber you can expect any temporary movement owing to acclimatization to happen much more quickly, but for shorter periods.
Cutting List For Table
|Quantity||Material||Finished sizes (length x width x thickness)|
|Legs||4||Oak||750 x 45 x 45 mm (29% x 1% x 13/ in)|
|Side Rails||2||Oak||1,950 x 70 x 25 mm (76% x 2% x 1 in)|
|End Rails||2||Oak||950 x 70 x 25 mm (37% x 2% x 1 in)|
|Top*||3||Oak||2,000 x 336 x 35 mm (78% x 1314 x 1% in)|
*The solid wood top is glued up from
three narrower boards. Allow 5 mm (3k in)
extra on component width and thickness
for sawn sizes, plus an extra 25 mm (1 in)
Alternative timber: Any tough, close-grained
Suggested finish: Oil or lacquer.
Marking and Cutting The Timber
Once you have selected your timber and brought it back to the workshop, select which board will give you which component on your cutting list. It helps to stand the boards on end so that it is easier to check both faces. The first crosscut is critical: although shorter boards are much easier to handle, once a plank is, say, 1,219 mm (4 ft) long instead of 2,438 mm (8 ft), the options for using that plank for lengthy components are obviously reduced.
Use a chalk line to mark cutting lines down the length of the rough-sawn board as shown. Do not attempt to cut to your finished sizes at this stage, but cut each component 5 mm (3/16 in) or so oversize.
Sawing along the chalk lines is best done on a band saw, although it is quite manageable with a jigsaw. Use the band saw freehand without any fence or guides, and simply guide the saw down the chalk line. A steady hand and good lighting around the band-saw table help accomplish this task. Make sure that your band saw is fitted with a sharp blade and is properly tensioned. Also check that the upper blade guide is set so that no more than 10 mm (3/8 in) of teeth are exposed above the timber. Keep your hands well back from the blade: although the band saw is a relatively gentle machine to use, it is still capable of inflicting very painful and damaging cuts.
It is possible to use a simple laser device to project a line along the timber, although this can be more work than using a chalk line. It involves using a pencil to :he path of the beam on the board, connecting marks with a straightedge.Lasers are also used for levelling, so shelving, cupboards, dado rails and so on can be aligned horizontally or vertically on a wall before drilling. In construction industry lasers have many uses, from out buildings to lining up timber roofs. They project lines at any angle – useful for marking out stair handrails. More sophisticated laser devices include digital measurement of length, area and volume at the press of a button. Distance range on :essional models can measure up to 200 m approximately 650 ft).
How to use a Chalk L
The chalk line is a hand tool that consists of a case filled with chalk dust and, typically, 30 m (approximately 98 ft) of 1 mm (1/32 in) braided cotton or synthetic line. You hook one end of the line over the board at your first measuring point and stretch the line to your second measuring point – in this case at opposite ends of the board. By flicking the taut line against the surface, you mark a chalk line. The tool is frequently used in the construction trade and is available from builders’ merchants.
1 First brush the boards you have selected with a wire brush to remove all dirt, grit and foreign material that may blunt your tools. Pull the line out of its case, through the chalk, and down the length of the board.
2 Snap the line against the board to leave a straight, clean chalk line on the timber.
Word Discription :
Chalk line Hand tool for marking lines using chalk dust.Cutting list A chart on which all the different components and sizes for a project are listed. This is very useful when you need to buy or select timber for a project. Laser line Electronic tool that emits a laser beam. Fitted to some power saws to give cutting line.