Effect of treatment process on performance of copper-chrome-arsenate. Part 2: Field stake tests

Pinus radiata sapwood stakes 20 x 20 x 400 mm³ were treated with CCA Type C using a range of concentrations and three treatment processes; Bethell, Lowry and Rueping. Preservative retention was determined by chemical analysis of treated material. Following fixation stakes were installed in a randomised plot in the Whaka graveyard located on the FRI campus. Stakes were inspected at yearly intervals using AWPA M-10 standard procedure. After 5 years' exposure performance was strongly correlated with preservative retention expressed either as copper retention or total element (Cu+Cr+As) retention. Treatment process had very little effect on performance and confirmed results obtained from similar material exposed in fungus cellar tests. Implications of these results for commercial treatment operations are discussed.