The Influence of Mechanical Surface Preparation Methods on Southern Pine and Spotted Gum Wood Properties: Wettability and Permeability

The demand for engineered wood products (EWPs) continues to rise internationally. However, for some important Australian commercial timbers such as plantation grown southern pine and native forest sourced spotted gum, a major impediment to achieving commercially viable EWP production is difficulties experienced in gluing – particularly for sawn laminate based EWPs such as glulam. Wettability and permeability have a major influence on wood adhesion. This study investigated the efficacy of different surface machining preparations on the wettability and permeability of southern pine and spotted gum. For both species, planing resulted in poor wettability, whereas face milling and sanding treatments post-planing improved wettability. Wettability increased in southern pine earlywood compared to latewood; and wettability decreased for both species with increased time post-surface machining. Planing resulted in the highest permeability for southern pine but the lowest permeability for spotted gum. Face milling resulted in higher permeability compared to sanding treatments.