Physical properties of Scots pine and Oriental beech treated with water repellents

Abstract

Water repellents resist water on the wood surface, contributing to the longer service life of the wood material owing to reduced water uptake and biological attack. This study was carried out to compare water-repellent substances with each other in terms of water absorption, weathering, surface roughness, and contact angle. Scots pine (Pinus sylvestris) and Oriental beech (Fagus orientalis) specimens were treated with silicone, paraffin compounds, and linseed oil according to a full-cell process. Following impregnation, the specimens were subjected to various tests including accelerated weathering (200 h), water soaking (2 weeks), contact angle, and surface roughness. Linseed oil exhibited the lowest water uptake in both Scots pine (37%) and Oriental beech specimens (28%) compared to paraffin and silicon oils, as well as untreated specimens, for two weeks. In the water-repellent-treated specimens, significant swelling occurred between 4 h and 24 h of water exposure. The beech specimens impregnated with paraffin exhibited the lowest color change (3.9) after 200 h of weathering. Silicon oil-treated Scots pine resulted in the highest contact angle after 100 and 200 h of weathering compared with the specimens treated with paraffin and linseed oil.