Magnetic resonance imaging as a potential tool in the study of wood penetration by waterborne preservative systems

This paper reports an application of magnetic resonance imaging (MRI) to the study of penetration by waterborne wood preservatives into wood. Samples of three wood species, red maple (Acer rubrum L.), ponderosa pine (Pinus ponderosa Dougl. ex Laws.), and aspen (Populus tremuloides), containing different anatomical features such as sapwood, heartwood, earlywood, latewood, and knots, were airdried and pressure-treated with water. Wood penetrated by water produced an intense signal and appeared bright, whereas those not penetrated by water produced no signal, and appeared dark. Heartwood of red maple was poorly penetrated by water, while sapwood was penetrable to water. Earlywood was more penetrable than latewood in both red maple and ponderosa pine sapwood. Knots in ponderosa pine were also poorly penetrated. Aspen sapwood was variable in penetrability. MRI provides a useful method for assessment of the penetrability of wood by water and consequently waterborne preservatives.