Seasoning and Preservative Treatment of Tanoak

One-hundred-twenty fresh-sawn 8-foot tanoak ties 7 by 9 inches and 23 ties 6 by 8 inches were seasoned; 12 of the smaller ties were incised prior to seasoning. Twelve of the large ties and all of the small ties were weighed. periodically. Half of the ties weighed were end-coated with filled gloss oil. The 7 by 9-inch ties were bored and check-bolted after being air-seasoned for 4 weeks; the check bolts were retightened twice. The ties seasoned from 100 percent moisture content to less than 30 percent in 13 months without check or long splits. Decay developed in some ties and became progressively worse with longer yard storage time. Incising, end-coating, and covering of the ties had no effect on seasoning. End-checking was less severe in the 6 by 8-inch ties. After 5 months, the end-checking in 7 by 9-inch ties was severe, the average maximum length of the checks on the sap face was 15 inches and 1/4 inch width. Twist developed in 21 percent of the ties; in 10 percent of the ties, twisting was moderate to severe. Check bolting did not appear to have had any beneficial effect. After 30 months, sporophores were noticed on 7 by 9-inch ties, 80 percent of the 6 by 8-inch tie contained decay, zone lines were present. Incised and unincised tanoak ties were treated with both creosote-petroleum and pentachlorophenol in heavy solvent solutions, both Lowry and Rueping processes being used. Results showed full-length ties and short tie sections were penetrated completely by both the Lowry and Rueping processes. Penetration was limited to the sapwood. Incising had no effect on penetration in either sapwood or heartwood. Higher retention, 8-23 lbs./cu.ft., were obtained by the Lowry process than the Rueping process (3-10 lbs./cu.ft.).

You must be logged in to download any documents. Please login (login accounts are free) or learn how to Become a Member