WEATHERING BEHAVIOR OF DIMENSIONALLY STABILIZED WOOD TREATED BY HEATING UNDER PRESSURE OF NITROGEN GAS

With the goal of improving the weathering behavior of wood by reducing its hygroscopicity and accompanying dimensional changes, samples of spruce and beech were heat-treated under nitrogen pressure at 175 to 195 C and subjected to natural and artificial weathering. Beech had a significantly lower hygroscopicity and improved dimensional stability after heat treatment and was more resistant to weathering than the unheated control. Although the hygroscopicity of spruce was also significantly reduced by heat treatment, weathering resistance was diminished, Heat treatment of either species had small, but measurable effects on the performance and durability of semitransparent and film-forming stains applied to the samples