Wood logs were supplied from Mamasani, Fars Province, from a population of planted eucalyptus trees. They were cut into 7x7x100 cm samples, and dried to below 20% moisture content.A split plot design was used for the experiment. Three impregnation methods namely Bethel, RUPPING and Double RUPPING along with three preservatives as against control samples were employed. A creosote and two other water soluble preservatives were prepared with proper pH using AWPA standard. Results are indicative of reactions of wood as well as internal wood elements to impregnation. A decrease was observed in the overall shrinkage in the treated samples. This was more pronounced in the Bethel creosote method. This indicates the stabilization of wood dimensions as a result of impregnation. Some reasons for this phenomenon could be cited as trans attachment of wood elements, subsequent drying in double drying process, and irreversible swelling. The specific gravity is less in treated samples as compared to control, this being more pronounced in the case of double RUPPING, and treated samples. with preservatives; chromium, fluorine and arsenic. This could be due to minor cracks on wood, microscopic cracks (inner layer fracture, cell wall ruptures, etc), increase in dimensions (of irreversible nature), and inflation of wood elements, double drying stresses and unexpectable leaching. Milder treatment methods such as RUPPING and use of less volatile elements of chromium, copper and arsenic (CCA) are preferred over others.

Wood samples of teak (Tectona grandis) , keruing (Dipterocarpus alatus), yellow balau (Shorea laevis) and chengal (Balanocarpus heimii) were treated by Creosote, using ruping method. The dimension of samples were 200x75x20 mm and the retention were 188, 186, 331, 40 kg / m9 respectively. Both treated and untreated samples were installed in sea water (Mahshar in Persian gulf and Bandar Torkman and Noshahr in Caspian sea coasts) according to IRG/WP-4432(1985). In Mahshar coast, after 6, 10, 20, 23, 27 months and in Caspian sea coasts every 6 months and after 11 years the samples were inspected according to recommendation of IRG/WP-4432(1985). In Mahshar coasts (Persian Gulf), during this installation period, the control samples (no treated) of chengal and keruing were sound, samples of balau were severely degraded and Teak samples seriously attacked. All the treated samples after 27 months installation in sea water, were sound. In Caspian sea coasts, expect soft rot on the samples surfaces, both treated and untreated samples after 11 years installation were sound. It is concluded that there are no marine borers in Bandar Torkman and Noshar in south coasts of Caspian sea.