Choosing Timbers for use in tropical climes
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Concise Descriptions of the Merits and Marked Characteristics of a Few Empire Timbers for Vehicles to be Operated Under Tropical Conditions By A Timberman
IN an article which appeared in The Commercial Motor dated January 13, a coachbuilding expert emphasized that it is a wise plan to study the conditions existing in a country to which lorry or bus bodies are to be sent. That is sound advice. Conditions vary enormously, making forethought necessary, not only in designing, but also in deciding the material to be wed.
It is regrettable that, in choosing the wood, such wisdom is seldom exercised, and often a commercial body going to a hot, humid climate will be built of the same kind of timber as one which will be employed in this country. If bodybuilders would remember that nature supplies a wood to suit every conceivable job and climate, there would be fewer false complaints of bad workmanship when the vehicle bodies reach their destinations.
The aforementioned contributor, referring to vehicles going to the Tropics, also stated that opportunity is afforded for using Empire timbers. Quite so. Empire woods are now generally traded in Great Britain, and among them are some of the finest woods in the world. The following are a few which have been tried and proved successful for vehicles going to the Tropics.
Insect and Fungus Will Not Attack This Timber
Rangoon Teak is brownish in colour, straight-grained and fairly hard, inclined to be heavy, strong and durable, and immune from insects and fungus. No matter to what variations of weather it be exposed, and in what temperature it be used, it will not warp, shake, or alter its shape.
This wood contains a large amount of resinous oil, which gives it extraordinary resistance to water and, what may be a bigger advantage, acts as a preservative against rust, when the wood is used in contact with iron. It needs no protective covering of any kind, and is a wood officially approved as fire-resistant. This timber may be used for any partof a vehicle, but like other really good commodities, it is expensive.
There is a cheaper timber called " Eng Teak," but this is quite distinct from the true teak described above, arid although it is not recommended for use in this country, it is largely used for vehicle construction in its native India. It is a straight-grained, durable, hard and tough timber, red to red-brown in colour, with a firm, close texture. It works satisfactorily, finishes well, and could be used as an inexpensive• wood required to stand heavy usage. Gurjun is one of the best Indian hardwoods on the market, is dull reddish-brown in colour, hard and oily (like teak) with a fine firm texture, and has a dose, even grain. An easy-working wood, it will finish to a fine surface and take a good polish. Unlike teak, it has a pleasant odour.
Apart from being a good constructional timber, g-urjun is an excellent decorative wood, and is recommended for the construction of the highest class of passenger vehicle. It can be obtained in long lengths and wide boards.
White Bombay is an attractive, inexpensive wood for interior fitting. A. firm, hard, close and even-grained timber, yellowish-grey to light brown in colour, often with darker streaks, it has a lustrous surface which takes a good polish. This timber does not warp or twist, and is of moderate weight.
Indian white mahogany is a lustrous yellowish-white timber, resembling a straight-grained, mild mahogany in general character and weight. It works easily and well, affording a smooth, silky surface, and takes stains readily. This timber has been found valuable for many purposes where ah easy-working material of good appearance is required, and for all classes of work the commoner mahoganies. • A Nigerian timber, sometimes sold as "African oak '' or "African teak," is Iroko, but, in reality, it is not related to either of those two standard timbers. Iroko is a strong, moderately hard, very durable timber, of fairly open grain, pale to dark brown in colour, and of good appearance. When well seasoned it does not warp or shrink, and excellent results are obtained with artificial seasoning.
Although some of the wood is inclined to be cross-grained, it planes well, and will take a good polish when filled. It is one of the best standing woods known, and, being "climateproof," is well adapted for use where a reliable wood is required at low cost. This wood can be used both for constructional and decorative purposes, and can be obtained in wide boards and long lengths.
A Nigerian Wood for Hard Wear and Tear
African walnut, also from Nigeria, is a walnut-brown timber, with dark brown or black bands which " figure " with great effect when the wood is polished. A hard and tough wood, it does not shrink, but its being rather cross-grained makes it somewhat difficult to work, although the time demanded is well spent. It has the disadvantage of being heavy, but, like most other woods which are heavy by nature, it will stand extremely hard wear and tear.
Yet another timber from Nigeria is Sapele mahogany, a wood more widely used on the Continent than in this country. It is moderately light in colour, has a. marked banded " roe," and is frequently handsomely figured and coloured. The working qualities are good, and the timber does not warp. Sapele mahogany is slightly harder and heavier than other African mahoganies, and can be used for constructional work.
Putpleheart, a valuable wood from British Guiana, is dense, tough, elastic and of great strength. When freshly cut, the timber is light brown, but the colour rapidly changes to purple on exposure. It seasons easily and well. The grain is close, and the timber works well with all tools, taking a fine smooth surface which polishes with the best results.
Spirit polishes should not be used in dealing with this timber. Purpleheart is an excellent ornamental wood of the heavy kind ; it is also well suited for purposes requiring a structural timber of great strength, especially where shock is to be resisted, It is highly resistant to damp.