Performance of boron/fluoride rod for internal remedial treatment of Douglas-fir poles

Abstract

The ability of boron and fluoride to migrate from a boron/fluoride rod was investigated over a 15 year period in Douglas-fir pole sections. Both components readily moved through the wood, but boron tended to be present at higher levels over the test reflecting the much higher boron content of the rods. The overall chemical levels suggested that higher dosages would be needed to more fully protect Douglas-fir poles.

Borates in remedial treatments for timber in service

“…External decay is usually arrested by application of external preservative pastes that supplement the original treatment and there are a number of tests evaluating different systems [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27]. The paste is applied to the exposed surface (usually below the ground) and covered with a kraft wrap to help contain the chemicals before the soil is replaced.…”

“…The alternative to liquids is to use solid rods that can be inserted into treatment holes that are plugged to help retain chemicals (Table 2; Figure 7). Alternatively, boron has been used in several forms as an internal treatment [40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][58]. Boron-based treatments for large timbers and poles are applied to holes drilled into the timber in the same fashion as the fumigants.…”

“…Fluoride also diffuses with water in the wood and the premise is that the two chemicals diffuse together and act synergistically. Field trials in softwoods have shown that the boron remains detectable for up to a decade after treatment, but the fluoride distribution is much more variable [24,[59][60][61]. These rods are also less concentrated than the fused boron/boroncopper systems, resulting in a lower overall dose.…”

Remote detection of termite activity in wooden bridge structures

“…These include length of time in service, regional environmental conditions (such as mean annual temperature, humidity, precipitation), among other factors, which can substantially increase the risk of degradation and reduce treatment efficacy . Multiple types and causes of degradation can occur simultaneously (such as excess moisture, decay fungi, wood-infesting beetles, termites) but require different remediation strategies (Moore 1979;Morrell et al 1986Morrell et al , 1996Lewis 1997;Yates and Grace 2000;Peterson et al 2006;Ahmed and French 2008;Austin et al 2008;Shupe et al 2008). Therefore, identifying the source of biodegradation is important so that effective control or treatment measures can be applied.…”

Performance of Internal Remedial Treatments on Douglas-Fir Poles: A Large-Scale Field Trial

“…Water-diffusible compounds, typically boron and fluoride, diffuse through wood with moisture and are active against both fungi and insects (Becker 1976;van der Drift et al 1987;Beauford et al 1988;Dickinson et al 1988;Henningsson et al 1988;Militz 1991;McCarthy et al 1993;Highley et al 1994Highley et al , 1996Morrell and Schneider 1995b;Powell et al 1998;Rhatigan et al 2002;Morrell et al 2011). Moisture contents above 27 percent are typically required for effective diffusion (Smith and Williams 1969).…”