froods that Save Vei ht
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Nywood, New Zealand hite Pine, Rimu, Western Hemlock, Yellow Pine, American Vhitemood, Silver Spruce, Cottonwood—These Materials are Reviewed
By A Timbertnan
READING the interesting artitles on bodybuilding. which . appear frequently in The Commercial Motor makes one realize how difficult the body-designer's task must be, especially. . in connec: tion with interior construction. Cost of material, utility, weight, strength and appearance are all points which have to be considered, to say nothing of the owner's whims and fancies, which must be respected.
The interior fitting of commercialmotor bodies varies greatly, atcording to the classes of goods which they are required to carry, and the aim of every designer is to reduce weight without impairing the neces sary strength. ,Therefore, a few particulars of some lightweight woods may be of interest.
Plywood Incomparable . . . .
For great strength, combined with lightness of weight and pliability, there is, of course, no material to compare with plywood. • With the aid of science and engineering skill, this object has been achieved with a degree of success beyond. the most sanguine expectations. To-day, 'plywood can be obtained in almost any size and thickness, and in woods th suit the most fastidious consumer's requirements.
However, plywood has its limits, and it should not be used for purposes where it will receive direct knocks or heavy chafing. Its chief assets lie in its ability to withstand great bearing stress, and in the fact that it can be obtained in a size impossible to procure in solid wood. . Of the two most commonly used plywoods, birch and alder, the latter is the lighter in weight. The approximate weight of 100 ft. super 8 mm. birch plywood is 40 lb. and that of alder 35 lb. The same quantity of 1-in. (25 mm.) birch plywood would weigh 340 lb., whereas alder of the same thickness would turn the scale at 300 lb.
N.Z. White Pine . . .
New Zealand white pine, an old and tried Empire wood, but seldom remembered by the younger generation, could be used with advantage in the place of deal for interior fitments. Considerably lighter. in weight than deal, New Zealand pine is white, or sometimes a pale yellow, in appearance ; straight in grain, even in texture, it is a firm and tough wood, and is obtainable in' great widths.
It has a bright surface and is easy to work. It is, however, essentially an'inside " wood_and is not durable when exposed to the weather. Its weight is about 30 llo. per cubic ft.
Rimu, also from New Zealand, is an excellent lightweight timber of handsome appearance, suitable for interior fitting. Light brown in colour—and, as seasoning proceeds, there appear lighter and darker streaks with striking effect—it is a strong softwood of fine close texture and fairly straight-grained.
For "Show. . . .
The wood works easily, even with hand tools, and takes a good polish. It would make a good "show " timber for the interior of vehicles. Its weight is about 35 lb. per cubic ft.
Western hemlock should be clearly distinguished from eastern hemlock, a much inferior timber. Both woods are imported from British Columbia. Western hemlock may be u5,e1 in the place of deal, with the advantage of lesser weight, for shelving and fitments required to withstand rough wear. ,
It is a non-resinous wood, strong and of fine, straight, even grain. It works easily to a good finish, takes paint and varnish well, and has gOod nailing and glueing properties. However, it is durable Only ' when under water, or kept 'dry. _ An obnoxious wood_ tovermin, it is well adapted for grain and other
• food-carrying vehicles. The average weight is 33 lb. per .cubic ft. .
Next to yellow pine,. American whitewood is probably the best lightweight commercial softwoOd. Primequality whitewood. is a pure canary colour, whilst the inferior qualities vary to a dark brown. It has a fine grain, inclined to be spongy, and the surface is dull.
An excellent wood for staining and polishing, it is One of the 'easiest woods to. work, being extremely mild in nature:'Itian be obtained in'
wide clinie4ioni-, is expeaSive, like . all first class material : . The average weight is 30 lb.: per 'cubic, ft.
Silver spruce, is a first-class softwood, which, owing to its lightness of weight, coriabined with ..strength, has been largely' used' in aeroplane construction. Lustrous white in appearance, it has a straight, even grain, and is tough elastic, and non
resinous. Silver spruce does not warp, a big advantage over yellow and white deal
Does Not Spilt . . . .
It works ea-sly and can be nailed without splitting. .However, when "opened," or cut, the grain has a tendency to rise, and, therefore, the wood should be painted or varnished soon after being worked. This timber imparts no taste, and is well adapted for the linings of refrigerator vehicles, beside being suitable for general interior fitting. The weight is 26 lb. per cubic ft. ..
Cottonwood comes from Canada and the United States, and, when thoroughly dry,' is even lighter in weight than silver spruce. White, yellowish-white, and sometimes brownish-white in appearance. it has a fine, open grain and is about as hard as deal.
It is a durable wood under dry conditions and does not readily take fire, but it should be well seasoned before use, as it is liable to warp. Cottonwood weighs on an average 27 lb. per cubic ft
Highly Expensive . . . .
Yellow,. pine, the premier softwood, can be used only where cost is a secondary consideration, for it is highly expensive. Its durability is, ; however,. so good under any conditiOns=ontside or inside work--that, in the _long run, it pays for the
initial:, outlay. It is light in colour, light in weight, soft, straight-grained, of fine and .even texture, and has a smooth, brilliantly lustrous surface and does not 'warp. Yellow pine, Which weigh k about 24 lb. per cubic ft., is a Canadian timber suitable for the highest-class light constructional work.