A marine borer test with water-borne preservatives
B Henningsson, E Norman
The use of preservative treated timber in sea-water where marine borers are active is of great economic importance, since untreated wood immediately will be damaged. Vacuum/pressure treated timber has been tested in several marine exposure trials on the Swedish west coast since the 1930s (Hager 1941, Hultman 1949, Sandstrom 1951, Nylinder-Norman et al. 1974). Since new interesting materials or preservative formulations are manufactured all the time, it is important to investigate their effect against the borers before they can be recommended and used in marine wood constructions. A Nordic standard method for testing wood preservatives in the sea was therefore worked out at the beginning of the 1970s (NWPC Standard No. 22.214.171.124./73). In principle following this standard an extensive test was started in 1972 to evaluate the effectiveness of various preservatives against wood borers. The test was located at the Kristineberg Marine Biology Station on the Swedish west coast. Results after the first 2.5 years (three growth seasons) were reported in 1975 (Norman and Henningsson). The present paper deals with the results after an exposure period of 6.5 years (seven growth seasons).