AMERICAN WOOD-PRESERVERS ' ASSOCIATION Effect of Source, Drying Method and Treatment Schedule on Treatability of Red Pine

Although sapwood of pine species is generally considered to be readily treated with preservatives, penetration is sometimes variable. The cause of this variability is poorly understood. This study evaluated the effect of geographic source, method of drying, and treatment parameters on penetration of a preservative in red pine lumber. Lumber from Wisconsin and Michigan was air or kiln dried and then conditioned to uniform equilibrium moisture content. Matched specimens were then treated with schedules that vaned in intensity of vacuum and pressure periods. The results indicate that penetration was influenced by anatomical properties inherent to the geographic source of the material. Adequate penetration was achieved using treatment schedules with longer pressure periods, but these schedules also resulted in higher weight gains. The method of drying appeared to have no affect on preservative penetration