Your search resulted in 51 documents. Displaying 25 entries per page.
Effect of treating process on efficacy of CCA in a laboratory decay test
1990 - IRG/WP 3628
Test samples of Pinus radiata sapwood measuring 40x40x500 mm³ were treated with a range of concentrations of the copper-chrome-arsenate (CCA) formulation "Tanalith C" using Rueping (empty cell), Lowry (empty cell) and Bethell (full cell) treatment processes. Samples were then reduced to 40x40x7 mm³ test blocks and exposed to the decay fungus Coniophora puteana using an agar/block technique. Repl...
M E Hedley, K Nasheri, J G Van der Waals
Inadequacies in preservative retention and formulation as contributory causes of premature failure of CCA-treated vineyard posts
1984 - IRG/WP 3280
Analyses of severely decayed or failed vineyard posts and examination of stake test data on effectiveness of copper-chrome-arsenate (CCA) preservatives have suggested two contributory causes of premature failure of vineyard posts: 1. Preservative retentions in posts are such that after 15 years' exposure some decay is inevitable. 2. The high arsenic, low chrome formulations with which the...
M E Hedley
Bacterial brown stain on sawn timber cut from water-stored logs
1992 - IRG/WP 92-1532
Brown stains which appear on the surface of sawn radiata pine cut from water-stored logs were identified as tannin-like compounds. They are derived from bacterial breakdown of flavanoid-glucosides. When timber is sawn from infected logs, the free flavanoids migrate to the wood surface as the timber dries. There, they condense and oxidise to form permanent brown discolourations. Stains occurred on ...
M E Hedley, R Meder
Multiple-Phase Pressure (MPP) Process: Pilot plant trials for disposal of kickback using reverse osmosis membrane filtration
2001 - IRG/WP 01-40202
The MPP Process (a one-stage CCA treatment and accelerated fixation process) generates ~ 250 litres of kickback per cubic metre of timber treated. Composition of kickback is mainly wood sugars and traces of copper, chromium and arsenic. In pilot plant scale trials, MPP process kickback was filtered through a Reverse Osmosis (RO) membrane of a type found from earlier small-scale trials to be the mo...
H Pearson, G Durbin, M E Hedley
A survey of the incidence of decay in copper-chrome-arsenate treated trellis support posts used in horticulture in New Zealand
1984 - IRG/WP 1225
Copper-chrom-arsenate treated softwood posts used as trellis support structures in 5 major horticultural districts of New Zealand were systematically examined for presence of decay. Principal crops on properties examined were grapes and kiwifruit; a minority of properties grew hops, boysenberries, and dwarf apples. Occurrence and severity of decay were variable within specific age classes of posts...
M E Hedley, J A Drysdale
Comparison of performance of wood preservatives in laboratory and field tests of treated commodities
1993 - IRG/WP 93-20010
The purpose of laboratory tests for evaluating efficacy of wood preservatives is usually to establish toxic values against standard strains of wood decay fungi. Exposure conditions are usually chosen as optimal for fungal growth. Toxic values so determined serve as a guide as to expected performance of the preservative in field stake tests or in above ground exposure tests. Test material is select...
M E Hedley
Patterns of decay in CCA-treated horticultural post populations - A fungus cellar simulation
1986 - IRG/WP 1286
The distribution of decayed posts in 10-, 14-, and 18-year-old vineyards supported a hypothesis to explain variability in intensity of decay found among posts in New Zealand horticultural properties. The development of decay patterns between samples in a simulated vineyard plot established in the Forest Research Institute fungus cellar gave additional support to the hypothesis that decay within la...
M E Hedley
Comparison of the FRIM and forest research laboratory methods for screening of anti-sapstain formulations
1999 - IRG/WP 99-20170
Two laboratory methods for screening of anti-sapstain formulations were compared. The method adopted by the Forest Research Institute Malaysia (FRIM) involved 3 weeks assessment of rubberwood (Hevea brasiliensis) blocks, dipped in the candidate formulation and inoculated with mycelial/spore suspension of sapstain (Botryodiplodia theobromae) or decay (Schizophyllum commune) fungi, and incubated on ...
A H H Wong, D R Eden, C M Chittenden, M E Hedley, R N Wakeling
Reduction of kiln brown stain in radiata pine lumber after log fumigation with methyl bromide
1997 - IRG/WP 97-30129
Methyl bromide fumigation of freshly felled radiata pine log sections effectively killed living cells in parenchyma to at least 75mm into sapwood. Lumber cut from logs (fumigated and control) stored 1 month outdoors (dry) showed slightly reduced brown stain when kiln dried at conventional temperatures. A more dramatic reduction and elimination of brown stain was noted in lumber cut from fumigated ...
E Schmidt, M E Hedley, D R Page, D Cross
Performance of copper-chrome formulations in ground contact in five test sites in New Zealand
1996 - IRG/WP 96-30113
Copper-chrome-arsenate (CCA), copper-chrome-boron (CCB), copper-chrome-fluoride (CCF) and copper-chrome-phosphate (CCP) have been tested at four retentions each in ground contact (25 x 50 x 500 mm³ radiata pine sapwood stakes) for 16 years in five test sites in New Zealand. Results to date show that test site characteristics have a marked effect on relative performance. In a warm and wet site (an...
M E Hedley, R N Wakeling, J Foster, B E Patterson
The multi-phase pressure (MPP) process. One-stage CCA treatment and accelerated fixation process
- The process as a new concept in preservative treatment
1997 - IRG/WP 97-40078
The background to current commercial CCA treatment schedules used in New Zealand and fixation processing is reviewed. The limitations of these conventional practices with respect to treated product quality and CCA solution handling issues are defined. A novel, patented treatment schedule has been developed using a combination of hydraulic and pneumatic pressure phases and hot (~ 75°C) CCA solutio...
K Nasheri, A J Pendlebury, J A Drysdale, H Pearson, M E Hedley
Effect of treatment process on performance of copper-chrome-arsenate. Part 1: Fungus cellar tests
1995 - IRG/WP 95-40045
Pinus radiata sapwood stakes 20 x 20 x 400 mm³ were treated with CCA Type C using a range of concentrations and three treatment processes; Bethell, Lowry and Rueping. Preservative retention was determined by chemical analysis of treated material. Following fixation, fungus cellar stakelets, 5 x 10 x 180 mm³ were cut from treated material and after leaching were exposed in unsterile soil beds in ...
M E Hedley, J Anderson, J B Foster, B E Patterson
Performance criteria for approving new wood preservatives for ground contact
1994 - IRG/WP 94-20021
Protocols for testing novel formulations prior to approval or registration as wood preservatives are being developed in a number of countries, e.g. Australia, New Zealand, USA. One aspect which must be addressed is the effectiveness in tests relative to that of currently approved formulations which would be acceptable to approving authorities. It is assumed that natural exposure testing is a prere...
M E Hedley
Performance of preservative-treated timber commodities in above-ground service tests
1995 - IRG/WP 95-20064
Service tests established by NZ FRI are of commodities where treatment has been undertaken in commercial plants and although such data as preservative uptake of individual items is recorded and sample analysis undertaken, material is usually "run-of-mill" for the commodity being treated. The NZ FRI Service Test database includes a wide range of preservative/species combinations in virtually all ab...
M E Hedley, D R Page
Administration of wood preservative usage in New Zealand
1977 - IRG/WP 395
Principal administration of the preservative treatment of timber in New Zealand is by the Timber Preservation Authority (TPA). The TPA was established in 1955 by Act of Parliament and is under the jurisdiction of the Minister of Forests who appoints its members. Its field staff are Forest Service employees. The Authority comprises twelve members and includes representatives of timber trade associa...
M E Hedley
Limitations of the Pilodyn when assessing decay in graveyard test stakes
1982 - IRG/WP 2168
The following examination was designed to evaluate more precisely the usefulness of the Pilodyn for routine, objective assessments of the condition of field test stakes and to examine its limitations, particularly in respect to: 1.) The importance of variables other than extent of decay which may affect Pilodyn readings; 2.) Practicality of obtaining multiple readings in decayed and non-decayed re...
M E Hedley
Multiple-Phase Pressure (MPP) Process: One-stage CCA treatment and accelerated fixation process. 4. MPP compared with other processes for achieving acceptable treatment of radiata pine heartwood
1998 - IRG/WP 98-40115
Although radiata pine sapwood is very amenable to preservative treatment, it is often difficult to achieve the required standard for heartwood treatment.
A preliminary investigation showed that to achieve the NZ Timber Preservation Council minimum penetration requirements for radiata pine heartwood using the Multiple-Phase Pressure (MPP) Process, a hydraulic pressure of at least 1250 kPa for 20 m...
K Nasheri, J A Drysdale, G Durbin, M E Hedley
Comparative performance of copper azole and copper-chrome-arsenate treated rubber wood in Australian, Malaysian and New Zealand tests sites
2000 - IRG/WP 00-30213
Rubberwood (Hevea brasiliensis) has been used for non-structural products where appearance is important. It has rarely been used for structural uses where preservative treatment is required. In order to evaluate the in-ground durability of preservative-treated rubberwood, test stakes (20 x 20 x 500 mm3) were treated to four retentions of CCA and copper azole (Tanalith® E) and installed in test si...
J A Drysdale, M E Hedley, E Loh, L T Hong
Multiple-Phase Pressure (MPP) Process: One-stage CCA treatment and accelerated fixation process. 3. Effect of process variables on sapwood treatment and CCA fixation.
1998 - IRG/WP 98-40114
The Multiple-Phase Pressure (MPP) Process achieves treatment and fixation as combined process using hot CCA, within a 2-3 hour time-frame. Timber is treated to saturation with hot CCA using an empty cell process. During the pneumatic pressure phase, hot solution is held in the wood in an otherwise liquid-free treatment vessel until fixation is >95% complete.
This report details a factorial des...
H Pearson, K Nasheri, J A Drysdale, G Durbin, M E Hedley
Efficacy of a novel copper-based organic solvent preservative in laboratory and fungus cellar tests
1995 - IRG/WP 95-30071
The efficacy of Chemicca 4, a novel copper-based organic solvent preservative, was compared with that of other LOSP in pure culture laboratory decay tests and with that of CCA and TBTO in a fungus cellar exposure. It was markedly superior to copper and zinc naphthenates at equivalent metal retentions in laboratory decay tests, and similar in activity to TBTO. After 60 months' fungus cella...
M E Hedley, P N Maynard
Performance of boron-treated radiata pine in above ground field tests in New Zealand
2006 - IRG/WP 06-30406
Boron treatment was approved for exterior, above ground use in New Zealand in 1958, provide treated commodities were painted with a three-coat paint system. Above ground tests of rail units and L-joints were established at the NZ Forest Research Institute (now Scion) between 1967 and 1980 to monitor performance of boron treatment in relation to that of untreated and CCA-treated timber.
Results sh...
M Hedley, D Page
Wood decay fungi from New Zealand ‘leaky’ buildings: PCR identification and laboratory decay tests of wood preservative-treated Pinus radiata (Part 1)
2007 - IRG/WP 07-10620
Fungi colonising Pinus radiata D. Don framing timber of ‘leaky’ New Zealand buildings were isolated to produce pure cultures. Mycelia from these cultures on agar media were collected to extract DNA. To identify the fungi to the species level, polymerase chain reaction (PCR) with primer pairs ITS1-F and ITS4 were performed followed by sequencing of the internal transcribed spacer (ITS) region. ...
D Stahlhut, R L Farrell, R Wakeling, M Hedley
Wood decay fungi from New Zealand leaky buildings – PCR identification (Part 2) and aerial spore trapping
2008 - IRG/WP 08-10649
Prior to this study, it was not know which species of decay fungi caused decay in New Zealand leaky buildings. Use of molecular biology methodology, polymerase chain reaction (PCR), and subsequent DNA sequencing, as well as classical mycological techniques based on morphology, has enabled identification of decay fungi and has provided insight into their relative importance based on isolation frequ...
D Stahlhut, R L Farrell, R Wakeling, M Hedley
A comparison of rates of decay and loss in stiffness of radiata pine and Douglas fir framing lumber
2008 - IRG/WP 08-20378
Stiffness loss with time was recorded for untreated radiata pine and Douglas fir framing size lumber and preservative treated radiata pine which dad been pre-inoculated with Oligoporus placenta, a brown rot decay fungus isolated from decaying untreated radiata pine framing. Between stiffness measurements, samples were contained in a plastic tank located outside at ambient temperature. Index of Con...
M Hedley, D Page, J van der Waals
A Method for Studying Boron Redistribution and Leaching in Timber Framing
2011 - IRG/WP 11-20476
In typical New Zealand timber framed house construction, the timber framing has a vapour permeable building wrap applied to the exterior and a cladding applied over 20 mm battens. An interior lining usually of gypsum plasterboard is then fixed once the timber framing has a moisture content of < 20%. Timber framing within the building envelope is not expected to be wet in-service or exposed to a le...
J A Drysdale, N Marston, M E Hedley