U.S. DEPARTMENT OF AGRICULTURE FOREST SERVICE FOREST PRODUCTS LABORATORY MADISON, WIS. 1165 The Forest Service, U.S. Department of Agriculture, is dedicated to the principle of multiple use management of the Nation's forest resources for sustained yields of wood, water, forage, wildlife, and recreation. Through forestry research, cooperation with the States and private forest owners, and management of the National Forests and National Grasslands, it strives--as directed by Congress--to provide increasingly greater service to a growing Nation. Experimental untreated southern yellow pine posts installed from 1936 to 1938 at the Harrison Experimental Forest, Saucier, Miss., had an average life of 3.3 years. Untreated longleaf pine posts installed in 1949 had an average life of 2.3 years, while those treated with a No. 2 fuel oil and with Wyoming residual petroleum oil have an estimated average life of 5 and 8 years, respectively. Of southern yellow pine posts installed from 1936 to 1941, those treated with boraxboric acid have all failed with an average life of 10.6 years, and those treated at the groundline and top with Osmoplastic have all failed after an average life of 11.2 years. Posts treated with the following preservatives and installed from 1936 to 1941 have had failures totaling 10 percent or less of the number installed and should last 42 years or longer on an average: pentachlorophenol, 4.8 percent in crankcase oil;~ copper sulfate and sodium arsenate applied by double diffusion; and zinc meta arsenite. Posts in test in 1936 to 1941 treated with other preservatives have an estimated average life of 8 to 41 years. 2 3 This Note is a continuation of annual progress reports under the same title, issued 1950-1962 as Forest Products Laboratory Report No. 1757 and since 1963 as U.S. Forest Service Research Note FPL-01. Maintained at Madison, Wis., in cooperation with the University of Wisconsin. Crankcase oils may contain chlorinated naphthalenes, which are reported to be a contributing cause of "X-disease" (hyperkeratosis) in cattle. These oils are therefore not recommended for preservative treatment of wood with which cattle may come in contact. |