The penetration of CCA on four under-utilized Malaysian hardwood species.
Four Malaysian hardwoods - mempening (Lithocarpus spp.), nyatoh nangka kuning (Pouteria malaccensis), pauh kijang (Irvingia malayana) and petai (Parkia speciosa) - were treated with copper chrome arsenate (CCA). Jelutong (Dyera costulata) and merbau (Intsia palembanica) were used as controls. There was a general correlation between wood density and wood preservative penetration: petai had the deepest side penetration, followed by jelutong, nyatoh nangka kuning, mempening, pauh kijang and merbau. Lower density species (jelutong, nyatoh nangka kuning, and petai) attained deeper penetration than the higher density species. There were significant differences in side penetration between the 6 species. It is concluded that the 4 under-utilized Malaysian timbers studied are treatable by vacuum-pressure CCA.