Your search resulted in 238 documents. Displaying 25 entries per page.
Comparative moisture uptake of Douglas fir and radiata pine structural lumber when exposed to rain wetting as an indicator of relative decay resistance
2004 - IRG/WP 04-20285
Trials were undertaken to determine the relative resistance of radiata pine and Douglas-fir to wetting when exposed to the weather.
Douglas-fir samples were obtained from one Central North Island and three South Island sources and had a heartwood/sapwood mix typical for each resource. Radiata pine sapwood and heartwood samples were obtained from a Central North Island source. Material was exposed...
M E Hedley, G Durbin, L Wichmann-Hansen, L Knowles
Relationship between bond strength and surface characteristics of CCA-treated Douglas-fir
1993 - IRG/WP 93-30008
Chromated-copper-arsenate (CCA) treated Douglas-fir was laminated using a commercial phenol-resorcinol resin. CCA treatment enhanced the water repelleney of wood espeeially in the presence of extractives. However, the shear strength of CCA treated wood was 12% lower in dry condition and 38% lower in wet condition after six cycles of vacuum-pressure test than that of untreated wood. Slight removal ...
K Yamamoto, J N R Ruddick
Serviceability of copper naphthenate-treated poles
2000 - IRG/WP 00-30214
Copper naphthenate-treated poles in service were inspected for deterioration, penetration, retention, and serviceability. The study to date has included poles in all hazard zones in the United States. Poles installed by 12 different utilities and eight different treating companies are included in the survey. Both southern pine and Douglas-fir poles and distribution and transmission poles are inclu...
H M Barnes, M H Freeman, J A Brient, C N Kerr Jr
Performance of boron and fluoride based rods as remedial treatments in Douglas-fir poles
1995 - IRG/WP 95-30070
Boron and fluoride are widely used for remedial internal treatments, but their use in North America has been limited. Recently, however, interest in these chemicals has increased as the result of concerns about the risks of fumigant usage. The performance of boron or a boron/fluoride combination was assessed in Douglas-fir poles over 1 to 3 year periods. Both chemical formulations diffused well th...
J J Morrell, P F Schneider
Fungal associates of Buprestis langi Mannerheim colonizing stored douglas-fir logs
1997 - IRG/WP 97-10220
Buprestid beetles are important colonizers of dead and dying conifers. The larvae of these beetles initially mine a gallery beneath the bark, then tunnel deep within the log. These beetles can cause extensive damage to wood, but it is their frequent association with internal fungal decay that causes the greatest concern. Many insects are capable of vectoring fungi that enhance their prospects for ...
C M Garcia, M Y Giron, J J Morrell
Termite-tunnels formation on the surface of termite-resistant wood species in field sites
2001 - IRG/WP 01-10400
In this report, termite-tunnels formation by the subterranean termite, Coptotermes formosanus Shiraki on the surface of termite-resistant wood species, namely, Hinoki (Chamaecyparis abtsu), Yoshino Hinoki (Chamaecyparis abtsu), Miyazaki Hinoki (Chamaecyparis abtsu), Hiba (Chamaecyparis abtsu) and Japanese cedar (Cryptomeria japonica) was conducted in field sites. Westernhemlock (Tsuga heterophylla...
Y Kadekaru, K Kinjo, S Yaga
Preliminary modelling of methylisothiocyanate movement through Douglas fir transmission poles
1988 - IRG/WP 3466
Methylisothiocyanate is a volatile solid that is the active ingredient of several registered and experimental wood fumigants. Information on the sorption and diffusion of this chemical in Douglas-fir heartwood and sapwood was used to develop a two-dimensional model of fumigant movement within a single horizontal cross-section of a transmission pole. The model indicated that dry wood (14% MC) stron...
A R Zahora, P E Humphrey, J J Morrell
Feasibility of using biological control agents to arrest and prevent colonization of Douglas fir and southern pine by decay fungi
1988 - IRG/WP 1345
The use of microfungi to control basidiomycetous decay has been evaluated in Europe for many years, where it has produced mixed results against Lentinus lepideus Fries, the fungus presumed to be the major cause of decay in Scots Pine poles. In the United States, remedial decay control has been largely chemical, with little use of alternative decay control strategies. Increasing restrictions on che...
J J Morrell, C M Sexton
The effect of glycol additives on diffusion of boron through Douglas-fir
2000 - IRG/WP 00-30235
Boron is highly effective against a variety of fungi and insects and is able to diffuse with moisture through wood. Diffusion decreases sharply at lower moisture contents, a characteristic that limits the potential use of this material as a remedial treatment for arresting internal decay. One approach to improvi ng boron diffusion is the simultaneous addition of glycol, which is presumed to enhanc...
C M Freitag, R Rhatigan, J J Morrell
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
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
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
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
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
"Refractory" is a relative term. Incised alpine fir is treatable
1991 - IRG/WP 3670
While certain wood species carry a reputation for being 'treatable' this normally refers to the sapwood. For most Canadian species, heartwood penetration is the major determinant of whether treatment meets Canadian, USA and Japanese standards and in this respect alpine fir turns out to be a treatable species. Alpine fir is the fir component of the Western Canadian spruce-pine-fir...
P I Morris
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