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Variation in natural durability of British grown Douglas fir ((Pseudotsuga menziesii (Mirb.) Franco). Part I. Effect of density and growth rate
2002 - IRG/WP 02-10445
Seed origin trials of Douglas fir (Pseudotsuga menziesii) in Britain have provided important information on growth differences between origins (Lines, 1987), but the variation in wood properties between origins has not been reported. The present paper describes a study of the variation in natural durability against two brown rot fungi (Coniophora puteana and Postia (Poria) placenta) and in a fung...
S Akhter, M D C Hale


Effect of kerfing on performance of Douglas-fir utility poles in the Pacific Northwest
1990 - IRG/WP 3604
Preservative treatment produces an external layer of protection in Douglas-fir poles, but the development of deep checks as the wood dries after treatment can permit entry by fungi and insects. A variety of remedial treatments can arrest this decay; however, it is far more efficient to prevent checking. Kerfing represents one potential method for limiting the development of deep checks. In previou...
J J Morrell


Cellular and fractural failure after supercritical fluid impregnation of four wood species
2004 - IRG/WP 04-10503
Supercritical fluids (SCFs) have been investigated for delivering biocides into sawn wood. Pressure differentials during treatment may exceed the compressive or tensile strength perpendicular to grain, creating a potential for transverse deformations that exceed elastic strain limits. Wood treated by SCF processing with CO2, a potential biocide carrier, was inspected macroscopically and microscopi...
M E Anderson, R J Leichti, J J Morrell


Ability of chloropicrin, Vorlex, or methylisothiocyante to prevent marine borer attack of Douglas fir piling
1989 - IRG/WP 4153
The preservative-treated shell around Douglas-fir piling is an excellent barrier to attack by marine borers; however, damage to this shell can permit marine borer attack. The feasibility of using fumigants to enhance piling performance was examined by exposing fumigant-treated Douglas-fir sections in marine waters off Newport, OR, or Port Hueneme, CA. The piling were inspected annually and increme...
M A Newbill, J J Morrell


Supercritical fluid impregnation of Douglas-fir heartwood with cyproconazole using temperature induced deposition
2003 - IRG/WP 03-40259
A limited understanding of the fundamental aspects of supercritical fluid (SCF) impregnation in wood remains an obstacle to the development of this technology. Developing a better understanding of the effects of various process parameters on treatment results would facilitate more rational development of SCF impregnation. In this project, the effect of treating period and specimen length on su...
Sung-Mo Kang, J J Morrell


The treatment of Douglas fir fence posts: specification and compliance using new European standards
1999 - IRG/WP 99-20178
New European standards for the preservative pre-treatment of timber require the results of the treatment process to be specified and subsequently verified by examination of the treated timber for penetration and retention of the preservative. For penetration, the standards are restrictive in that there are only a limited number of options available to the specifier. Thus for ground contact service...
R J Orsler, H Derbyshire


Movement of borates in a range of timber species at various moisture contents
1998 - IRG/WP 98-30181
Borate-based wood preservatives are used in industrial pre-treatment as well as remedial treatment of timbers in situ. In both of these areas, understanding the mobile nature of these compounds is important in optimizing the main benefits of borates. Considerable work has been conducted on movement of borates in dip-diffusion treatment of freshly felled wood, as well as focusing on subsequent diff...
M W Schoeman, J D Lloyd, M J Manning


A comparison between high and conventional incision densities for improving preservative treatment of Douglas-fir heartwood lumber
1993 - IRG/WP 93-40009
Incising is required for the preservative treatment of most wood species from the western United States; however, there is considerable debate about the density of incisions required to achieve adequate treatment. Previous studies have shown that the incision effect on treatment is relatively narrow, suggesting that incision densities should be significantly increased over current practices and st...
S T Lebow, J J Morrell


Effects of Prior Establishment of Trichoderma harzianum on Ophiostoma picea Growth in Freshly Sawn Douglas-fir Sapwood
2003 - IRG/WP 03-10476
Trichoderma harzianum has been shown to be an effective biocontrol agent against a number of wood inhabiting fungi under laboratory conditions, but this fungus has performed poorly in field trials. Understanding the interactions between biocontrol agents and their intended targets in wood may provide important clues for developing improved approaches to biocontrol, potentially reducing our relianc...
Ying Xiao, J J Morrell, L M Ciuffetti


Potential for using dip/supercritical fluid treatments for wood impregnation
2004 - IRG/WP 04-40276
While supercritical fluid impregnation offers tremendous potential for impregnating wood species that resist conventional liquid preservative treatments, the resulting treatments are often not uniform among samples in a charge or between charges. One factor that influences treatment is the dynamic change in pressure that occurs during introduction of the biocide laden supercritical fluid into the ...
Sung-Mo Kang, J J Morrell


Fluoride movement through Douglas-fir and hem-fir lumber following dipping in potassium/ammonium bifluoride
1995 - IRG/WP 95-40040
The ability of ammonium and potassium fluoride to diffuse through Douglas-fir and hem-fir lumber was evaluated over a 90 day period. Boards were dipped in a solution containing 10% (by weight) of ammonium and potassium bifluoride, then stored under cover for 90 days. Samples removed 30, 60 and 90 days after treatment indicated that the fluoride was unable to completely penetrate the wood. Penetrat...
J J Morrell, C S Love


Variation in natural durability of British grown Douglas fir ((Pseudotsuga menziesii (Mirb.) Franco). Part II. Effect of extractive contents and taxifolin
2002 - IRG/WP 02-10446
The previous paper (Part I: Effect of density and growth rate) described the variation in natural durability of 4 Douglas fir (DF) seed origins (Darrington, J. Landing, Naselle and Hawkinsville) in a pure culture decay test and fungal cellar test. The pure culture tests were performed against two brown rot fungi (Coniophora puteana and Postia placenta). In the fungal cellar test soft rot was the p...
S Akhter, M D C Hale


Sterilization to limit pretreatment decay: Internal temperature during kiln drying of Douglas-fir poles
2001 - IRG/WP 01-40206
Sterilization to limit pretreatment decay: Internal temperature during kiln drying of Douglas-fir poles. Fungal colonization of poles following peeling has been the subject of considerable concern among electric utilities. While the presence of fungi does not, in itself constitute a risk, the survival of these fungi through the conventional treating processes could allow them to continue to degrad...
J J Morrell, P G Forsyth, K L Levien


Effects of air-seasoning on fungal colonization and wood strength of Douglas fir poles
1987 - IRG/WP 1315
Air seasoning economically reduces the moisture content of Douglas fir poles before pressure treatment with preservatives. Advanced decay in poles in service has resulted when decay fungi (Basidiomycetes) colonized poles during air-seasoning and survived the treatment process. These problems have led to recommendations to severely limit this practice. To determine the role of these fungi in peeled...
J J Morrell, M E Corden, R D Graham, B L Kropp, P Przybylowicz, S M Smith, C A Sexton


Effect of substrate type and moisture requirements in relation to colony initiation in two carpenter ant species
1999 - IRG/WP 99-10320
Conditions necessary for optimal colony initiation or the rate of initial colony expansion by early brood in the carpenter ant species Camponotus modoc and C. vicinus on various substrates conditioned to different moisture contents were studied. Camponotus modoc and Camponotus vicinus queens were placed in Douglas-fir, western red cedar and Styrofoam® blocks conditioned in sealed chambers at 70% ...
M E Mankowski, J J Morrell


Effect of species composition of preservative-treated Douglas fir plywood on its decay resistance
1978 - IRG/WP 2114
Plywood is now commonly used for constructional purposes in environmental situations where decay by wood-destroying fungi can be a considerable risk. However there seems to be a lack of understanding of the relative durability of plywood, both untreated and when treated with wood preservatives. Part of the reason for this situation has been the difficulty of carrying out laboratory decay tests on ...
R S Smith, P Balcaen


Development of threshold values for boron compounds in above ground exposures: Preliminary trials
1998 - IRG/WP 98-30179
Boron is increasingly used both as an initial and remedial treatment for protecting wood against fungal and insect attack. While establishing lethal dosages for boron against insects through feeding tests is relatively simple, establishing thresholds for fungal attack poses more of a challenge. Tests using boron dispersed in agar artificially surround the fungus with both boron and excess nutrient...
J J Morrell, C M Freitag, S Unger


Effects of chemical pretreatment of Douglas-fir heartwood on efficacy of potential bioprotection agents
1990 - IRG/WP 1440
Biological protection against wood decay fungi represents an environmentally attractive alternative to the use of chemicals; however, the process of identifying suitable candidates and the conditions that ensure successful protection pose major challenges. One critical aspect of this problem is to identify organisms that can rapidly and uniformly colonize the wood. Wood contains low levels of nutr...
B Dawson-Andoh, J J Morrell


Effect of post-treatment processing on leachability of ACZA-treated douglas-fir lumber
1998 - IRG/WP 98-50109
The effect of post-treatment procedures that more rapidly precipitate copper, zinc, and arsenic in douglas-fir treated with ammoniacal copper zinc arsenate (ACZA) on subsequent leaching resistance were investigated at two retentions (6.4 and 40 kg/m3). Total leaching was greater from boards treated to the higher retention. At both levels, copper was lost at the highest rate. Post-treatment process...
J J Morrell, C S Love, S Kumar, C M Freitag


Internal pressure development in Douglas fir lumber during pressure treatment
1997 - IRG/WP 97-40091
Preservative treatment of Douglas fir lumber to meet current industry standards poses a major challenge and a variety of methods have been developed to overcome these problems. One aspect for treatment improvement that has received less attention is the relative effect of treatment parameters on changes in pressure within the wood. Previous studies of spruce and radiata pine suggest that internal ...
P F Schneider, J J Morrell


Distribution of boron from fused borate rods in Douglas-fir transmission poles
1996 - IRG/WP 96-30112
The diffusion of boron from fused borate rods (disodium octaborate tetrachydrate) was monitored over 42 months in CCA-treated Douglas-fir transmission poles. The boric acid equivalent was estimated by the curcumin/salicylic acid color test on increment cores removed from the poles. Moisture content of the poles was quite variable but was always above 20 percent. The percent of increment core lengt...
T L Highley, F Green III, W F Finney


Movement of chloropicrin, Vapam, and methylisothiocyanate in southern pine and Douglas fir timbers
1987 - IRG/WP 3410
Douglas fir and southern pine timbers, 15.2 x 15.2 x 426 cm³ (6-in x 6-in x 14-ft), were "inoculated" with brown-rot and white-rot fungi as vapor-sensing agents to evaluate the movement and distribution of fungitoxic concentrations of chloropicrin, Vapam, and methylisothiocyanate (MIT) over a 20-week period. Residual fumigant in timbers was determined by a bioassay with Gloeophyllum trabeum. The ...
T L Highley


Effect of humidity and temperature on fastener withdrawal resistance from CCA and ACZA treated Douglas-fir
2000 - IRG/WP 00-20209
The effects of preservative treatment on fastener withdrawal was investigated in Douglas-fir lumber conditioned to two moisture regimes. In general, conditioning samples to 19% moisture content produced more substantial changes in withdrawal resistance of galvanized fasteners than did conditioning to 12%. Treatment had little or no effect on withdrawal resistance of stainless steel fasteners. With...
Sung-Mo Kang, J J Morrell


Borate diffusion from fused borate rods in douglas-fir transmission poles
1994 - IRG/WP 94-30042
Pressure-treated utility poles have given many years of excellent service, but their lifetime is often shortened by internal decay of the untreated heartwood center, particularly in refractory species, such as Douglas-fir. This paper reports the distribution of boron from fused borate rods installed in CCA-treated Douglas-fir transmission poles. The boric acid equivalent was roughly monitored by t...
T L Highley, W Finney, F Green III


Fixation and leaching characteristics of Douglas-fir treated with CCA-C
2004 - IRG/WP 04-50213
Fixation and leaching characteristics of CCA-treated Douglas-fir was evaluated using the expressate method and the AWPA E11-97 leaching procedure. CCA fixation, as monitored by the chromium reduction, was much faster in heartwood than in sapwood; however, copper and arsenic fixation in heartwood appeared to be incomplete regardless of the extension of fixation time. This poor fixation of copper a...
Gyu-Hyeok Kim, Yun-Sang Song, Dong-heub Lee


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