Physical and chemical analysis of softwoods exposed to marine borers

Wooden materials have been used for shipbuilding and structural purposes in the seas since ancient times.Wood being used in the sea water can be damaged by marine boring organisms and this can lead to decreasing the service life and economical loss. Using naturally durable species and preservative treated wood can increase the service life and they can withstand the damages caused by marine borers.In this study, Scots pine (Pinus sylvestris L.), Crimean pine (Pinus nigra Arn. subsp pallasiana var. pallasiana) and fir (Abies nordmanniana) woods being naturally grown and economically important wood species of our country, were exposed to marine testing for 7 and 14 month periods in Amasra vicinity of Western Black Sea region.The specimens were prepared according to TS EN 275 standard. They were treated with Tanalith-E wood preservative. The concentration of Tanalith-E was chosen as 2,36%. The specimens (both control and preservative treated) were placed in the testing site according to TS EN 275 standard.According to retention analysis, Fir wood was treated very well but Crimean pine wood was found fairly difficult to be treated.According to marine test results, Teredo navalis was identified as a marine boring organism. Tanalith-E treated fir and Scots pine specimens were found in almost perfect condition after 7 and 14 months of exposure except very minor damaged four wood panels. However, Tanalith-E treated Crimean pine wood panels were damaged quite heavily. All of the control panel specimens were destroyed.It is concluded that Teredo navalis is an important marine boring organism in this region. The average largest shell diameter was found as 4,79 mm in Scots pine. And the longest pallet was found as 4,71 mm in Crimean pine. The highest average mass loss was found in fir as 66,54% and the lowest was 33,13% in Scots pine.According to chemical analysis results, the cellulose ratio of Crimean pine decreased from 56% to 50%, and the holo-cellulose ratio decreased from 76% to 71%. The other results were found quite similar. Alcohol solubility decreased in all of the specimens as a result of the damage. However hot and cold water solubility increased.