A comparison between methods for evaluating the water repellency of wood
Wood specimens treated with a number of water repellent formulations have been tested for their water repellency according to four laboratory test methods, based on weight increase, swelling and contact angle measurements, in order to assess the degree of agreement between the different methods. Treatments representing formulations with a wide range of water repellent efficiency were tested both initially and after simulated weathering. A ranking of the water repellent treatments shows deviations between the different test methods although the general agreement is relatively good. Contact angle measurements are less appropriate due to a poor repeatability. The development of new standard test methods where the long-term performance or water repellent treated wood is evaluated by a weathering procedure is of great importance.
Keywords: CONTACT ANGLE; PINUS SYLVESTRIS; SOAKING; SWELLOMETER; TESTING; WATER REPELLENTS; WEATHERING; WEIGHT GAIN CURVES; ARTIFICIAL WEATHERING