Marine borers resistance of chemically modified portuguese wood
MADERAS : Ciencia y Tecnología
This study deals with the role of hardness and chemical toxicity in the resistance of pinewood to marine borers. Portuguese wood Maritime pine (Pinus pinaster) was modified with 1,3-dimethylol 4,5-dihydroxy ethylene urea (DMDHEU), methylated methylol melamine (MMF), tetraethoxysilane (TEOS) and two types of wax. In addition, for comparative purposes, different control species, Ipê, Beech and Blue Gum and CCA treated pine were included. All specimens were exposed over 2 years in sea (Porto,
... in sea (Porto, north of Portugal). Three inspections were performed after exposure (6, 12 and 24 months). The influence of type and level of modification as well as hardness was evaluated. As results: Specimens modified with resin have shown slight or trace attack by Teredinids in DMDHEU with low level of modification (10% of weight percent gain, WPG); MMF resin with high and low level of modification (25% and 10% of WPG) have shown trace to moderate attack, respectively. With the TEOS and wax impregnated wood which fill the cell lumens no significant difference in marine borers attack was found as compared to unmodified control specimens, despite the increased hardness. Cookson, LJ.; Scown, DK.; McCarthy, KJ.; Chew, N. 2007. The effectiveness of silica treatments against wood-boring invertebrates. Holzforschung 61(3): 326-332. Cragg, SM.; Danjon, C.; Mansfield-Williams, HD. 2007. Contribution of hardness to the natural resistance of a range of wood species to attack by the marine borer Limnoria. Holzforschung 61(2): 201-206. De Palma, J. 1980. Co-operative trials to investigate the effect of timber substrate on the effectiveness of water-borne preservatives -panama test site results. International Research Group on Wood Preservation, Document 80-458, Raleigh, NC, USA. Donath, S.; Militz, H.; Mai, C. 2004. Wood modification with alkoxys. Wood Science and Technology 38(7): 555-566. Donath, S.; Militz, H.; Mai, C. 2006. Creating water-repellent effects on wood by treatment with silanes. Holzforschung 60(1): 40-46. Eaton, RA.; Hale, MDC. 1983. Wood: Decay, Pest and Protection. Chapman & Hall, London. Eaton, R.; Ampong, F.; Barnacle, J.; Beesley, J.; Bultman, D.; Cookson, L.; Cragg, SM.; Depalma, J.; Gambetta, A.; Henningsson, B.; Levi, M.; Levy, C.; Nilsson, T.; Orlandi, E. 1989. An international collaborative marine trial to investigate the effect of timber substrate on the efficacy of CCA and CCB wood preservatives. Material and Organism 24(1): 51-79. EN 275. 1992. Wood preservatives. Determination of the protective effectiveness against marine borers. European Standard, Bruxelles. EN 335-2. 1994. Durabilidade da madeira e de produtos derivados -Definição das classes de risco de ataque biológico, Parte 2: Aplicação à madeira maciça. European Standard, Bruxelles. EN 350-1. 1994. Durability of wood and wood based products -natural durability of solid wood. Part 1. Guide to the principles of testing and classi4cation of the natural durability of wood. European Standard, Bruxelles. EN 350-2. 1994. Durability of wood and wood based products -natural durability of solid wood. Part 2. Guide to natural durability and treatability of selected wood species of importance in Europe. European Standard, Bruxelles. EN 460. 1994. Durability of wood and wood based products -natural durability of solid wood. Guide to the durability requirements for wood to be used in hazard classes. European Standard, Bruxelles. EN 1534. 2000. Wood and parquet flooring -determination of resistance to indentation (Brinell)test method. European Standard, Bruxelles. Epmeier, H,; Westin, M.; Rapp, A. Wepner, F.; Militz, H. 2005. Fungal resistance, dimensional stability and accelerated weathering performance of N-Methylol treated veneers of Fagus sylvatica. In: Militz, H.; Hill, C. (Hg): Wood modification: Processes, properties and commercialisation. The 2 nd Conference of Wood Modification ECWM, Göttingen, 169-177. Westin, M.; Lande, S.; Schneider, M. 2004. Wood furfurylation process and properties of furfurylated wood. International Research Group on Wood Preservation, Document 07-40289, Ljubljana, Slovenia. Westin, M.; Rapp, A.; Nilsson, T. 2006. Field test of resistance of modified wood to marine borers. Journal Wood Material Science and Engineering 1(1): 34-38. Westin, M.; Rapp, AO.; Nilsson, T. 2007. Marine borer resistance of modified wood -Results from seven years in field. International Research Group on Wood Preservation, Document 07-40378, Jackson Lake Lodge, Wyoming, USA.