A Weathering Device for Paintwork and Fabrics.
Page 27
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rilHE TEST of prolonged use is very 1often the best and most inexpensive way of ascertaining the durability and serviceability of any part of a motor vehicle, be it mechanical or otherwise. It is sometimes extremely difficult to approximate in the laboratory or test room the changing conditions met in every-day service, or the widely divergent factors encountered in different countries. But so far as upholstery, hood materials, lacquer and paintwork are concerned it would appear possible to obtain a very good idea of the effect which changes of temperature and weather have upon them by the use of an interesting. little device known as the Fadeorneter: The apparatus is largely used by the Studebaker Corporation of America, whose engineering staff was responsible for its design.
The principle of the device can be gathered from the accompanying dia
grammatic drawing. In its simplest form it consists of a cylindrical container, around the sides of which samples of the material to be tested are suspended. This container is made to complete a full revolution once in 24 hours and, during the course of its travel, it passes points at which a series of artificial weather conditions are produced. For instance, in one section a steady stream of water is directed for three hours on to the fabric, paintwork or lacquer to be tested, in another the conditions of a warm moist summer night are simulated for five hours, whilst for the remainder of the 24 „hours, light of a more intense degree than that at noon in midsummer is constantly maintained. The last-named is produced by a violet carbon arc lamp which produces a light n6arly identical with sunlight.
The light rays which destroy colouring and disintegrate dye in fabrics, as used for upholstery and hoods, are those which are not visible to the naked eye—the ultra-violet and infra-red rays which have chemical and heating properties respectively. The lamp used in the Fadeometer creates a large proportion of these rays. "
It has beep discovered that the sunlight of June and July possesses an effect that is more than six times as destructive as the light of December. Moreover, six hours in midsummer give the greatest light intensity, whereas in winter less than four hours supply light of any appreciable intensity. For this reason it is obvious that the weathering properties of an article can be more quickly ascertained by the use of the apparatus we have briefly described, for it maintains maximum destructive effort throughout a period of 24 hours. It is claimed that it takes only four days in a laboratory to measure the weathering of body finish for four months' outdoor use. By means of the Fadeometer the Studebaker Co. are able to discard any colour or material which will not withstand the ravages of the elements. Furthermore, by means of special baking ovens and refrigerators they are able to determine in advance the effects of arctic cold and tropical heat.