ACETYLATION PLUS WATER-REPELLENT TREATMENT OF WOOD IN SLATE THICKNESS

Wood specimens of cedar, juniper, spruce, poplar, alder, and beech in slate thickness (9.0 x 2.5 x 0.5 cm) were acetylated and subsequently impregnated under pressure with a water-repellent formulation consisting of 3% paraffin wax, 15% linseed oil and 82% white spirit. Weight gains of 15.4-18.9% were obtained after acetylation of 4 hours and 27.0-40.1% after acetylation plus water-repellent treatment. Water absorption of the actylated specimens was found to be 25.0-34.4% after a water soak lest of 72 hours with the exception of poplar slates. While poplar gave the highest absorption (56.3%), juniper showed the lowest values. Under the same conditions, except poplar, water absorption of all the samples acetylated and subsequently treated with the water repellent formulation was 10.9-14.8%. The poplar slates absorbed 22.7% of water. Water-repellent effectiveness of the acetylated wood species was 33.9-45.2%. Poplar slates had the highest values. The specimens acetylated and impregnated with the water repellent formulation showed a water-repellent effectiveness of 69.8-80.3%. The highest values were found for alder slates. © 1990 Walter de Gruyter