Abstract

Extracts of 13 tropical hardwoods in cold water, hot water and 0. 5 NaOH sol. were compared with those of Pinus kesiya in relation to their inhibitory effect in cement setting. Extraction with cold water was sufficient to remove inhibitory extractives from most of the species tested. Macaranga peltata was found to be the most promising for cement-bonded wood-wool board manufacture and Terminalia paniculata, the least suitable. A knowledge of the pH of cold water, hot water and mild alkali extracts and the extent of acidity will help not only in screening suitable species for cement-bonded wood-wool board manufacture but also in choosing the suitable method of extraction