Your search resulted in 29 documents. Displaying 25 entries per page.
Long-term performance of a "wax" type additive for use with water-borne pressure preservative treatments
2000 - IRG/WP 00-40159
Field performance results are updated for matched CCA treated decking boards with and without an emulsion water repellent additive incorporated with the initial pressure treatment. Decks have been exposured for over 9 years in Harrisburg, NC. Boards were evaluated for in-service and laboratory performance for water repellent efficacy, as well as additive loadings in the boards after this exposure....
A R Zahora
Marine performance of preservative treated Southern pine panels. Part 2: Exposure at Mourilyan Harbour, Queensland, Australia
2000 - IRG/WP 00-10337
Southern yellow pine panels treated with ACQ type B, ACQ type A, CCA type C, creosote, and copper naphthenate have been exposed at Mourilyan Harbour, north Queensland, Australia for almost 6 years. These panels have been inspected and rated for fouling and attack by Teredinid, Limnoria, Martesia, and Sphaeroma during this exposure. After 70 months exposure, overall performance of ACQ type B was eq...
A R Zahora, A F Preston, K J Archer, S Kleinschmidt
The influence of wood moisture content on the fungitoxicity of methylisothiocyanate in Douglas fir heartwood
1987 - IRG/WP 3430
The fumigant methylisothiocyanate (MIT) effectively controls decay fungi in large wood structures, but the influence of environmental factors on its performance are not well understood. Experiments found wood moisture content to greatly influence the fungitoxicity and sorption of MIT in Douglas fir heartwood. At constant, low MIT vapor concentrations (less than 1 µg/cc air), wood at 10% MC bound ...
A R Zahora, J J Morrell
Influence of pre-swelling conditioning on swellometer results for CCA and water repellent additive treated wood
1997 - IRG/WP 97-20125
The pre-test moisture content and conditioning history of wafers cut from wood treated with CCA and an emulsion water repellent additive can dramatically influence swelling curves generated using a standard swellometer apparatus. The rate of water uptake and swelling increased significantly as wafers were dried to lower moisture contents prior to immersion swelling. The pre-swelling conditioning h...
A R Zahora
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
Comparative field performance of CCA and CCA-water repellent treated Southern pine lumber
1995 - IRG/WP 95-30089
This paper describes the field performance of end-matched southern pine boards treated with either CCA type C or CCA type C containing an emulsion water repellent (WR) additive. Boards were either kiln or air-dried after treatment, constructed into decks, and exposed for over 3 years at Harrisburg, NC. During this exposure, matched boards were monitored for internal moisture content, cupping at mi...
A R Zahora
Interactions between water-borne preservatives and emulsion additives that influence the water repellency of wood
1991 - IRG/WP 2374
Incorporation of non-polar additives into water-borne treatments through of emulsion technology can greatly improve the physical characteristics of wood in service. Of specific interest with these emulsions is their effectiveness in reducing the rate of wood swelling. We have observed that the presence or absence of preservatives can often significantly influence the resultant effectiveness of the...
A R Zahora
Pretreatment decay in air-seasoning Scots and Corsican pine poles in England
1989 - IRG/WP 1390
British grown Scots and Corsican pine poles were sampled for colonization by basidiomycetes after air-seasoning for 6 to 9, or 16 to 20 months. The amount of infection present in these poles was compared with that in poles which were imported from Finland. After 6 to 9 months seasoning, the British grown pine poles were heavily infected with Peniophora gigantea, Cylindrobasidium evolvens, Stereum ...
A R Zahora, D J Dickinson
Effect of a water repellent additive on the performance of ACQ treated decks
2000 - IRG/WP 00-40168
The performance of a water repellent (WR) additive formulated for use with ACQ has been evaluated. The water repellency of wood treated with this formulation was studied in laboratory and field tests. The change in moisture content of ACQ/WR treated boards under field exposure conditions is compared with that of CCA/WR treated boards. Although the water repellency of the ACQ/WR system is lower tha...
F Cui, A R Zahora
Marine performance of preservative treated Southern pine panels. - Part 1: Exposure in Newport, Oregon
2000 - IRG/WP 00-10368
The ability of selected wood preservative to protect southern pine sapwood against marine borer attack was evaluated over a 6 year period in Yaquina Bay, Oregon. The site exposed the wood to potential attack by both Teredo navalis and Limnoria spp. Both creosote and CCA provided excellent protection at moderate retentions, while ACQ produced slight differences in performance depending on the coppe...
R G Rhatigan, J J Morrell, A R Zahora
Performance of Oriented Strandboard, Medium Density Fiberboard, Plywood, and Particleboard Treated with Tebuconazole in Supercritical Carbon Dioxide
2005 - IRG/WP 05-30364
The performance of oriented strandboard (OSB), medium density fiberboard (MDF), particleboard and plywood treated with tebuconazole using supercritical carbon dioxide was investigated over a 48 month exposure under harsh above ground conditions in Hilo, Hawaii. Samples treated to low retentions (<0.20 kg/m3) tended to experience decay at rates that were only slightly lower than those found wit...
J J Morrell, M N Acda, A R Zahora
Wood preservatives treatment of black spruce
1997 - IRG/WP 97-40092
A representative sample of black spruce logs from Central Newfoundland was harvested and processed to dressed 2"x4" lumber. Over 400 pieces of lumber were then incised and treated with ACQ preservative in a semi-industrial retort. 9 charges of 20 samples were used to determine treating parameters and 11 charges of 20 pieces were treated using the optimized process. This material was inspected by a...
A R Zahora, J P Hösli
The ground proximity decay test method
2000 - IRG/WP 00-20205
A decay field test method, which has been recently proposed for the standardization by the AWPA, is described for evaluating the relative performance of wood samples in a severe above ground situation exposed to the weather. Data is presented on the relative performance of untreated control samples and standard preservative systems exposed at the same site at different time periods, or at differen...
A F Preston, P J Walcheski, K J Archer, A R Zahora, L Jin
Gelatin encapsulated fumigants for wood fumigations: Current research status
1985 - IRG/WP 3336
The fumigants chloropicrin (trichloronitromethane) and methylisothiocyanate (MIT) were encapsulated in gelatin as an alternative to liquid fumigant treatments for control of decay fungi in wooden utility poles. Gelatin-encapsulated MIT was stored for over 2 years under dry conditions without significant fumigant leakage. Gelatin encapsulated MIT and chloropicrin were released from capsules when pl...
A R Zahora, M E Corden, J J Morrell
A simple field apparatus for measuring relative gaff penetration and assessing the effect of additives for improving pole climbability
2000 - IRG/WP 00-20187
A simple apparatus for measuring and comparing the relative "hardness" of utility poles is described. This "slide-hammer" gaff penetration apparatus was designed as a field testing unit to measure the depth of gaff penetration into test poles after application of a uniform and reproducible force to the gaff. The apparatus is simple to use in both the laboratory and field. Data is provided for resu...
A R Zahora
The control and pretreatment decay in air seasoning Scots and Corsican pine poles in England
1990 - IRG/WP 1451
Previous work clearly showed that air-seasoned, British grown Scots and Corsican pine poles are subject to serious pretreatment decay. In order to control these infections a range of pretreatments are currently being investigated. One series of treatments is designed not only to control decay but also allow the development of mould and stain fungi in order to achieve the desired increases in poros...
D J Dickinson, A R Zahora, A P Dodson
Field Stake Tests with Copper-based Preservatives
2008 - IRG/WP 08-30459
The performance of field test stakes derived from commercially produced ground contact retention
copper quat preservatives based on either soluble copper complexed with ethanolamine, or from a water-based suspension of particulate micronized copper compounds, as well as untreated southern yellow pine controls, is compared at two decay test sites. After less than one year in field test some of t...
A Preston, L Jin, D Nicholas, A Zahora, P Walcheski, K Archer, T Schultz
Above Ground Field Testing – Influence of test method and location on the relative performance of various preservative systems
2008 - IRG/WP 08-20393
Standardized above ground tests such as the lap-joint or test deck methods can be very slow in producing useful information on the relative performance of wood preservative systems. It often requires many years for decay to develop in wood treated to sub-optimal concentrations of standardized preservatives, making relative comparisons of performance between new systems and established preservativ...
A Zahora
Performance of dip and pressure treated wood in termite ground proximity exposures in Hilo, HI, and Colombia
2008 - IRG/WP 08-30491
A number of preservative systems were evaluated for their ability to control termite attack when applied as both dip and pressure treatments. With dip treatments, better performance was observed with southern pine than spruce-pine-fir using the same solution strength treatment, probably as a result of the about 50% greater uptake with southern pine and associated deeper preservative penetration. B...
P Walcheski, A Zahora
The Relative Performance of an Organic Preservative System under UC3A and UC3B Conditions using Two Test Methods
2010 - IRG/WP 10-20429
Coated L-joints have been used for decades to evaluate the performance of wood preservatives in protected environments. This study was conducted using matched coated and uncoated L-joints to simulate above ground protected and unprotect exposures. When exposed to constant moisture in a greenhouse environment, coated and uncoated L-joints give very similar performance results. In contrast, exposi...
C F Schauwecker, A Zahora, A F Preston
Influence of Copper Preservative Type on Earlywood and Latewood Distribution of Copper in Treated Wood
2010 - IRG/WP 10-40507
Some of the new water based copper containing wood preservative systems use particulate “micronized” copper as the primary biocide instead of the more traditional soluble amine copper based systems. Studies were conducted to investigate how this difference in the type of copper system might impact both initial and post drying distribution of the preservatives in wood. Of specific interest wa...
A Zahora
Above ground testing at tropical test sites, what have we learned?
2011 - IRG/WP 11-20473
Three different above ground test methods have been utilized at a selection of five tropical and sub-tropical test sites with a variety of treated and untreated material. The results show that a multi-site approach to above ground field tests presents the opportunity for exposure to un-predicted biodeterioration hazards, which may be important for developmental products of poorly characterized fu...
A Preston, A Zahora, Y Cabrera, L Jin, C Schauwecker, P Walcheski
Further Studies on the Distribution of Copper in Treated Wood Using an XRF Microscope Technique
2011 - IRG/WP 11-40549
There are two distinct forms of copper in aqueous copper based wood preservative systems that are currently used in the United States for treatment of southern pine lumber. These are systems using either soluble copper (typically amine based) or the more recent particulate or “micronized” copper as the primary biocide. Studies reported last year showed that there were distinct differences in...
A Zahora
Use of the durable species Coast Redwood as a reference system for field testing of Wood Protection systems
2012 - IRG/WP 12-20486
Data is provided and discussed for a number of field exposure tests where the naturally durable wood species Coast redwood, Sequoia sempervirens, was included along with untreated pine and standard preservative treatments. In general, there is potential for higher variability of results with this naturally durable species, but it does suggest that redwood can be a useful reference material for te...
A Zahora, A Preston, L Jin
Performance of Wood Protection Systems at Multiple Field Test Sites Using the Ground Proximity Test Method
2012 - IRG/WP 12-20499
A series of preservative systems were used to treat southern pine ground proximity test samples which were then exposed at a range of test sites located throughout the world. The sites were chosen on the basis of having vastly different Scheffer Climate decay indices. After almost 14 years exposure, distinct differences are apparent in how different preservative systems perform at the different ...
A Zahora, A Preston, L Jin