The Technique of FURNITURE MAKING
Plywood dimensions
In all usual sizes the length of the face grains is given first, irrespective of the length of the sheet. Thus a plywood sheet quoted as 48 in (122 cm) by 72 in (183 cm) will be 72 in (183 cm) in actual length and 48 in (122 cm) wide across the sheet and parallel to the direction of the face grain. Such a sheet is cross grained as distinct from long grained, as the face grain of the former runs counter to the length of the sheet, and it is important to remember this when choosing sheet sizes, for subsequent face - veneering which must be at right angles to the face grain of the sheet. Thus two wardrobe ends each 6 ft (183 cm) by 18 in (46 cm) which are to be face-veneered must be cut from a sheet 36 in (92 cm) by 72 in (183 cm), and not from one quoted as 72 in (183 cm) by 36 in (92 cm) in which the face grain runs the length of the sheet. Thicknesses in plywood commonly available with their nearest inch equivalents are as follows:
|
mm |
in |
mm |
in |
|
0.8 |
1/32 |
8 |
5/l6 |
|
1.2 1.5 |
1/16 |
9 12 |
3/8 |
|
2 |
3/32 |
12.5 |
1/2 |
|
3 |
1/8 |
15 |
5/8 |
|
4 |
5/32 |
18 |
3/4 |
|
5 |
3/16 |
22 |
7/8 |
|
6 |
1/4 |
25 |
1 |
Plywoods can normally be obtained in any of the following wood species: agba (tola branca), alder, basswood (Japanese lime), European and Japanese beech, European birch, Chilean pine, Douglas fir (Columbian or Oregon pine), elm, gaboon (okoume), lauan, limba (afara), African mahogany, makore, red meranti, obeche, Parana pine, European pine, poplar, sapele, sen, red and white seraya, red and white sterculia, tamo (Japanese ash), utile and yang. Most suppliers will, however, only stock the most popular, i. e. gaboon, lauan, birch, alder, Douglas fir, and limba, etc. Of these gaboon, birch and limba are excellent for veneering, but gaboon is inclined to woolliness in face-work, and birch is difficult to stain evenly. On the other hand, limba is medium textured, moderately hard and stiff, and its natural light gold-brown colour can be stained in simulation of oak, walnut and mahogany, therefore making it a good all-round choice. In all cases the wood species quoted refer to the face veneers only, and not to the cores, which may be of low-density woods.
