OSU three year study results (compiled and visualized as bar graphs) Cu-Bor vs Others. Southern Yellow Pine poles, Georgia Power. Remedial treatments Cu-Bor, Cobra, and Cop R Plastic.
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 10
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 (reated posts were generally sound at the groundlinc, but mOSI
suffered top decay. The average borax retention was 1.5 1,0.99 and 0.66 Ibs/ff after 3.5, 6.5 and 10 years,
respectively.
Southern pine sapwood blocks, treated with creosote at sub-threshold level, were retreated with either copper hydroxide or sodium tetraborate and evaluated by laboratory soil-block tests to determine efficacy of retreating creosote-treated wood with short chain amino copper compounds and borates. The unexpected copper synergism with creosote confirms that amine copper complexes from copper hydroxide are highly synergistic with creosote for controlling Neolentinus lepideus, the creosote-tolerant fungus. The compatibility of copper hydroxide and sodium tetraborate decahydrate with creosote suggests that these chemicals can be used effectively for retreatment of creosote poles.
It must seem, to management personnel in the electric utility industry, that the field of wood technology as applied to wood preservation is more art than science and more conjecture than objective data. He is used to dealing in things which can be measured in ohms and volts, in a thousandth of an inch, and in dollars and cents. Unfortunately, treated wood poles are not like insulators, capacitors, transformers, etc. They differ as do the personalities of the people working for a utility and consequently, in dealing with wood poles, one must be ready to acknowledge the very considerable differences which can exist, and will exist, between poles cut from an identical environment and produced by the same supplier.
Wooden utility poles provide safe, economic, easily obtainable means of delivering
power, communications, and cable television to the masses of industrial and
residential locations throughout the world. Wood, however, is a biological commodity
that can undergo deterioration by insects, decay fungi, termites, and mechanical
destruction. In many ways wood poles, can outlast materials constructed of synthetic
materials like concrete, fiberglass, steel and aluminum if well maintained and cared
for in a consistent and timely manner.
In this study, a wood preservative containing active ingredients of 43.5% borax and 3.1% copper hydroxide was evaluated in soil-block tests in accordance with AWPA E10. Results suggested that the copper hydroxide was not contributing to fungal toxicity at preservative threshold levels. Thresholds determined for this preservative were very close to those previously reported for sodium borate. For this preservative, the soil-block test results in this study were less effective than the field test results.
While preservative treatment provides excellent long term protection against fungal attack in a variety of
environments, there are a number of service applications where the treatment eventually loses its effectiveness.
Soft rot fungi can then decay the wood surface, gradually reducing the effective circumference
of the pole until replacement is necessary
A groundline remedial treatment containing 3.1% copper hydroxide (2% elemental copper) and 40% sodium tetraborate decahydrate (borax) was applied to unseasoned pine posts prior to placement in a test site in southern Mississippi. The soundness of the posts was periodically evaluated using a push test. After 3.5, 6.5, 10, 15 and 20 years, sections were taken from two posts to determine retention of borax and copper hydroxide as a function of vertical position above ground and distance from the wood surface. Within 3.5 years of exposure all untreated control posts had failed. The upper portion of the treated posts became severely decayed after 6.5 – 10 years, but assay sections removed from posts were sound for 15 years. After 20 years one post remained sound through-out the assay area, while the other post was exhibiting some decay at groundline and above.