Plywood

“ Builders use plywood panels for interior walls and ceilings and for insulation, sub-floors, sheathing, shelving, cupboards and built-in units. The richness of wood-paneled rooms can now be enjoyed at a cost that compares favorably with other wall coverings. The paneled interiors do not go out of style or require redecoration. They are not damaged by water or shock and ordinary breakage. They do not crack or peel. ”

“ Aberdeen enthusiasts identify themselves by means of the "Glad Hand," also made of local plywood. There are more than 30 wood- working plants of various types near the water front, and their output includes furniture, sounding boards for pianos, and numberless items of woodenware. The lumber industry finds itself today at the beginning of a new era, in which chemistry and scientific technological processes will permit a fuller exploitation of the economic possibilities of the wood cell. Illus- trating this development is the comparatively recent rise of wood pulp, rayon, and paper manufacture. ”

“ The first thing he cut was the stocks for deck plank, hauled them out, and some of them into the barn, in order to keep his men at work sawing in rainy weather, and in order to permit the plank to season. He next began to cut his floor. We have said that the modern carpenter takes a mould for every timber into the woods. What do you suppose Charlie did? He took a pole, thirteen feet long, the length of his longest floor timber, with the dead rise of each timber marked on one side, and the length of each, in letters of the alphabet, on the other. ”

“ The Wood-Pulp Floor.—Floors have been accused of great sins. If the timber is not thoroughly seasoned they warp; if the boards are not properly laid they creak; and the cracks are all at times filled with injurious dust and dangerous germs. Why not invent a wood-pulp floor which shall have no warps, and no cracks, and no creaks? Dry the pulp to powder to facilitate transportation, mix with a small amount of cement, to increase the resistance of the floor, and then after making it a gelatinous mass pass it between rollers. When dry, paint it to imitate oak or other wood. ”

“ Each piece of timber was cut from a tree of larger or smaller size, as the case required, but they did not split the tree lengthwise to get several pieces of timber; for the heart being harder and more compact than the sap-wood (which is the spongy envelope beneath the bark) , and the concentric layers of wood being the closer and tougher in proportion to their nearness to the bark, if you split a tree in two lengthwise one of its faces is much more resisting than the other, the equilibrium is disturbed, and flexure is easily produced under a weight. ”

“ There was plenty for every one to do.
The first step was to choose suitable timber, and a species of Scotch fir was decided on, which grew conveniently upon the neighbouring hills, and seemed altogether well adapted to the multifarious uses to which it would be put. For in the rough and ready style of habitation which they were planning, there could be no variety of material; and every part of the house-outside and inside walls, flooring, ceiling, partitions, rafters, ridges, framework, and tiling-would have to be contrived of planks, beams, and timbers. ”

“ Much basswood is cut into veneer, some of which serves in single sheets as in making small baskets and cups for berries and small fruits, but a large part of the output is devoted to ply work. Usually three sheets are glued together, but sometimes there are five. By crossing the sheets, to make the grain of one lie at right angles to the next, plies of great strength and toughness are produced. Trunk makers are large users of such, and many panels of that kind are employed by manufacturers of furniture and musical instruments. ”

“ The specifications under which the timber was treated were as follows:
Timber.
The timber for creosoting shall be long-leafed or southern pine. Sap surfaces on two or more sides are preferred.
[38] Piles.—The piles shall be of long-leafed or southern pine, not less than 14 in. at the butt. They shall be free from defects impairing their strength, and shall be reasonably straight.
The piles shall be cleanly peeled, no inner skin being left on them. The oil used shall be so-called creosote oil, from London, England, and shall be of a heavy quality. ”

“ Wood in its quality and uses like white cedar. Thick, red heartwood, changing to reddish brown when seasoned. Thin sapwood, nearly white, coarse, straight grain, compact structure. Light, not strong, soft, very durable in contact with the soil, not resinous, easily worked, does not burn easily, receives high polish. Used for timber, shingles, flumes, fence posts, coffins, railway ties, water pipes, interior decorations, and cabinetmaking. A very large tree, limited to the coast ranges of California, and forming considerable forests, which are rapidly being converted into lumber. ”

“ The grain of the centre layer is laid at right angles to that of the other two, so as to give additional strength and to avoid warping. "Three-ply" will not split easily and should be used for the jointed animals and swinging animals described in Chapter XX.
Ply-wood is usually sold in thicknesses varying from 1/8 inch to 1⁄4 inch. Price of three-ply boards in large squares for cutting up:
1/8 in. thick, 47" × 38", 3/4d. per sq. foot.
3/16 " 53" × 34", 1d. " "
1⁄4 " 72" × 48", 1-3/4d. " "
Match Stales. ”

“ Lumber and timber with diagonal grain is always weaker than straight-grained material, the extent of the defect varying with the degree of the angle the fibres make with the axis of the stick. In the vicinity of large knots the grain is likely to be cross. The defect is most serious where wood is subjected to flexure, as in beams. ”

“ We have for the upper table, or front, a thin slab of wood known as pine, from a species of tree that grows all over the world. The varieties are, however, innumerable and the purposes to which they are put, equally so. For the lower table, or back, a more dense and tough wood is used. That the particular kind used in the construction of the famous instruments of the great masters, and mostly that known as curled maple or "hare wood," was chiefly on account of its beauty, is evident from the fact that all the best Italian makers had recourse at times to other and less showy wood. ”

“ Instead of fashioning the blocks into patent dice, hexagons, polygons, or dove-tailed complications in any form, we have only to slice barked trees of any size or quality into cylindrical slices about thirteen inches in thickness, and put the largest size down first into a good rammed foundation, and then the smaller sizes, until the remaining interstices may be filled up with what may be called pegs, the proper ramming of which will render the whole one solid mass of timber, while the economy of wood is so great that not a chip will be wasted. ”

“ The first is typical of any dry thin-walled cells, as is usually the case in seasoned white pine and spruce, and in the early wood of hard pines, hemlock, and other species with decided contrast between the two portions of the growth ring. As a rule buckling of a tracheid begins at the bordered pits which form places of least resistance in the walls. In hardwoods such as oak, chestnut, ash, etc., buckling occurs only in the thinnest-walled elements, such as the vessels, and not in the true fibres. ”

“ So hard, indeed, is the wood, that I have often kindled a fire on the timber floor of my workshop, without any injury to the apartment. The durability of such dense wood is of great importance, for around the cultivated fields we have neither hedges nor stone walls, the fences being entirely constructed of timber. A single tree may be found sufficient to fence an acre. ”

“ When the direction of the fibers is nearly parallel with the sides and the edges of the board, it is said to be straight-grained; when the lumber is taken from a crooked tree, it is said to be cross-grained, as the grain follows the shape of the log, while the board is sawed straight. Cross-grained lumber is the handsomer; in this the fibers, being at different angles with the surface of the board, form a variety of figures, which add much to the beauty of the wood. ”

“ All lumber used for outside finish should be thoroughly seasoned, clear, smoothly dressed, and free from imperfections tending to impair its use, durability, strength, or appearance. Poplar is the ideal building material for outside finish. It takes paint better than other woods used for this purpose. However, pine is generally used, for the reason that it is cheaper. Weather-boarding is usually laid with an inch lap four and one-half inches to the weather; three and one-half inches is better. ”

“ Vertical grain and flat grain may be had in both softwood and hardwood, but the vertical grain shrinks and swells less than the flat, is more uniform in texture, wears more evenly, and the joints open much less. Finished flooring consists or tongue-and-groove material of various thicknesses and widths.
Despite a slight tendency to splinter and wear irregularly over a period of years, plain wide planking of random-width boards makes an appropriate floor for a log building. ”

“ They attack the exposed surface of the wood and immediately begin to bore. The tunnels, often as large as a lead pencil, extend usually in a longitudinal direction and follow a very irregular, tangled course. Hard woods are apparently penetrated as readily as soft woods, though in the same timber the softer parts are preferred. The food consists of infusoria and is not obtained from the wood substance. The sole object of boring into the wood is to obtain shelter. ”

“ The timber of such a tree while still in one piece is strong, but, when cut, it is weak, because the grain slants across the several pieces. Carpenters call such wood 'short lengths,' because they thus cut it up for use. Again in general wood which comes from a moist, sheltered, shady or confined position is inferior both for carpentry and for fuel. ”

“ All hardwoods contain a multitude of long continuous water-conducting tubes termed wood vessels; in cross section they are often visible to the naked eye as pores. In woods like oak and ash these pores are easily visible in cross section as minute holes, and in longitudinal section as fine grooves, which are often accentuated by furniture makers through treatment with a dark filler. In woods like maple and gum the pores are too small to be seen without a microscope. ”

“ On account of its slow growth, its complete exhaustion has often been predicted, but a second growth has appeared which, though much inferior to the virgin timber, can be used in many ways to excellent advantage. Instead of the huge piles of cedar flooring, chest boards, and smooth railings of the old days, one now sees at points of distribution great piles of knotty, rough poles, ten to forty feet long, which years ago would have been discarded. ”

“ If a tree had no limbs, and merely laid on each year a layer of wood made of parallel fibres fitted on each other like pencils in a box, wood splitting would be child's play and carpenters would have less care to look after their tools. But woods differ in structure, and all fall short of the woodworker's ideal. The fibres of oak vary in shape and size. They taper and overlap their ends, making the wood less easily split than soft pine, for instance, whose fibres are regular cylinders, which lie parallel, and meet end to end without "breaking joints." ”

“ Now, by taking 131⁄2 on the blade for run, and 12 inches on the tongue for rise, and stepping along the valley rafter timber 12 times, the length of the valley will be found. The blade will give the heel cut, and the tongue the plumb cut.
In Fig. 38 is shown the slope of the roof projected into the horizontal plane. By drawing a figure based on a scale of one inch to one [Pg 26] foot, all the timbers on the slope of the roof can be measured. Bevel 2, shown in this figure, is to fit the valleys against the ridge. ”

“ Cleavage along tangential lines is easy with some woods. The line of cleavage follows the soft springwood. Green timber is generally, but not always, more easily split than dry. As a rule, the more elastic a wood is, the more readily it may be split. ”

“ In ring-porous woods of good growth it is usually the middle portion of the ring in which the thick-walled, strength-giving fibres are most abundant. As the breadth of ring diminishes, this middle portion is reduced so that very slow growth produces comparatively light, porous wood composed of thin-walled vessels and wood parenchyma. In good oak these large vessels of the early wood occupy from 6 to 10 per cent of the volume of the log, while in inferior material they may make up 25 per cent or more. ”

“ While the value of pulpwood is dependent basically upon the tons of dry pulp that can be produced from a given number of dry tons of wood, the great quantity of the wood is bought and sold either on the basis of an estimated and variable volume of wood in an assumed space, or on the theoretical quantity or volume of lumber which can be cut. ”

“ The next largest use of lumber is the grinding of it into pulp to be used in making paper for our books, magazines and newspapers, wrapping papers, etc. The woods used for this purpose are mostly spruce and hemlock. The great sources of supply of pulp-wood are Maine and Wisconsin, and large amounts are imported from Canada, which greatly lessens the drain on our own forests. ”