Authors: William Abbott, Douglas Crawford, Stan Lebow, Bessie Woodward, Randy Gross, Michael West
This paper was originally presented May 9, 2000 at the Ninety Sixth Annual Meeting of the American Wood-Preservers' Association. This report includes 10 years of data. Current photographs have been added.
ABSTRACT: In 1993 unseasoned pine posts were treated with groundline bandages containing 3.1 %
copper hydroxide and 40% sodium tetraborate decahydrate (borax). The soundness of the posts was
periodically evaluated using a push test. After 3.5, 6.5 and 10 years two treated posts were sacrificed to
determine borax retention and copper hydroxide retention in increments from cross sections ranging from
7 inches below ground to 14 inches above ground. After 3.5 years all untreated control posts had failed.
After 6.5 and 10 years the remedially treated posts were generally sound at the groundline, but most
suffered top decay. The average borax retention was 1.5 1, 0.99 and 0.66 Ibs/ft3 after 3.5, 6.5 and 10 years,
respectively. The average copper hydroxide retention in the sampled increments was 0.23, 0.26 and 0.22
lbs/ft3 after 3.5, 6.5 and 10 years, respectively. Although retentions varied among posts, in most cases the
borax retentions were still above the threshold needed to prevent attack by decay fungi even 10 years after