The efficacy of polyurethane coatings on wood samples exposed in the marine environment. Final Report -10 Year Assessment
R A Eaton
The results of an IRG collaborative marine trial to investigate the long-term permanence and efficacy of polyurethane coatings against marine borers are reported. PU-coated wood samples were exposed at a range of sites from tropical to cold temperate locations. The marine borer species present at the sites included teredinids, pholads, limnoriids and sphaeromatids so that each site offered its own peculiar degree of hazard. At most sites the integrity of the PU-coating was sound and wood samples were undamaged by marine borers after periods of exposure extending up to ca. 10 years. Where damage to the wood was recorded, mechanical abrasion of the coating had exposed the wood to attack by teredinids and pholads at one site and at a second site, sphaeromatids had perforated the coating. The significance of the results is discussed in terms of the protection afforded to submerged maritime timber structures coated with elastomeric polyurethane.