Editor's Note: WAR PAINTS AND THEIR COMPOSITION By E. C. Wood Manufacturers of paints are confronted with their full share of dislocation when war conditions upset the normal flow of raw materials from abroad. But paints must be available. And so there begins with the advent of war, in the paint industry, a strenuous search for substitutes. When China, Manchuria, Brazil, and the Pacific areas can no longer be steadily depended upon for shipment, the manufacturers turn their gaze to the castor bean and forage fish for oils, to the chemists for resins and colors, and elsewhere for other substitute materials. Moreover, these substitutes must accord with new methods of finishing and with new labor-saving equipment. The following article briefly narrates the nature of the paint problem in this crisis and how it is being coped with. China, perilla from Manchuria, oiticica from Brazil, gums and resins from north Pacific areas, and pigments from varied sources are all combined in peacetime formulas. Upon the outbreak of war, however, the paint pattern changes. As supplies of exotic materials become scarce and prices begin rising, paint and varnish laboratories the world over, and particularly in the United States, begin revamping their formulas to accommodate substitute materials. They turn to the castor bean and the forage fish for oils, to the chemist for resins and colors, elsewhere for other substitute materials. Following the war, when normal sources of supplies are again opened, and when prices decline to fair levels, the old formulas are dusted off and the paint chemist takes a much needed vacation. Meantime, however, some of the substitute materials may have proven so satisfactory that they are retained and become regular ingredients of peacetime paints. At present, wars are so widespread that a number of raw material sources have been cut off completely, while supplies from others have been curtailed. Tung Oil Supplies Sharply Curtailed Supplies of tung oil, also known as Chinawood oil, have been scarce for a year or so and are becoming scarcer, American requirements of this oil have been coming almost entirely from China, and since the Sino-Japanese war supplies have been curtailed to the point where prices have risen to prohibitive levels. In the first half of 1940 imports of Chinese tung oil, though below normal, amounted to 60,000,000 pounds. In the corresponding months of the current year receipts dropped to only 15,750,000 pounds. Supplies of Manchurian perilla oil have also been sharply curtailed. Receipts amounting to 6,014,475 pounds in the first half of 1940 declined to only 3,988,307 pounds in the corresponding current half-year. Substitutes Had To Be Found To offset shortages of these valuable drying oils, special types of linseed oils, and combinations of soybean, linseed, oiticica, fish, and castor bean oils are being utilized, in increasing quantities as substitutes in the preparation of paint products. The most outstanding substitute perhaps is the recently. |