Further observations on the durability of some common Indian timbers treated with creosote: fuel oil in Cochin harbour waters
Cheriyan, P.V.; Rao, M.V.; Cherian, C.J.
Journal of the Indian Academy of Wood Science 18(2): 69-77
Seventeen-year data on resistance to marine borers are reported from tests with wood of 12 species (2 from various locations), untreated or treated with creosote/fuel oil (50:50) at 2 absorption levels (160 and 320 kg/msuperscript 3) [and suspended in iron frames below low tide]. The performance of the same species from different localities varied: samples of treated Shorea robusta from Uttar Pradesh were destroyed in 10-13 yr, while samples from West Bengal and Bihar (which absorbed more preservative) were still under exposure tests. Samples of Tectona grandis from Andhra Pradesh performed better than samples from Madras. Less than 60% destruction had occurred in samples of Terminalia paniculata, S. robusta (West Bengal), Pinus roxburghii, Tectona grandis (Andhra Pradesh), Dipterocarpus indicus and Xylia xylocarpa treated at the higher absorption level, while untreated controls of these species lasted only 2-8 yr. Non-durable timbers such as S. robusta (Bihar and West Bengal), P. roxburghii and Terminalia paniculata were as durable as relatively more durable species such as Tectona grandis (Andhra Pradesh), D. indicus and X. xylocarpa when treated. Differences in performance with original preservative loadings became more evident with time of exposure - generally a greater loading gave better durability. Other species for which data are reported are: Alstonia kurzi, Bombax insigne and Tetrameles nudiflora (all of poor durability, and rejected early in the trial), Albizzia [Albizia] sp., Polyalthia fragrans and Pterocarpus dalbergioides.