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Treatment of Selected Lesser Used Timber Species against Subterranean Termites using Heartwood Extracts from Teak (Tectona grandis) and Dahoma (Piptadeniastrum africanum)
2007 - IRG/WP 07-30434
Lesser used timber species represent a valuable material for all-purpose uses but the problem is that most of them are not durable. They have, for this reason, been treated with all manner of chemicals to enhance their natural durability, especially in the tropics. Often, most of these chemicals pose a threat to the environment. Currently, one probable measure of avoiding such a threat to the environment and organisms is to treat non-durable timbers with extracts from other durable species. Some Ghanaian lesser used timber species were impregnated with heartwood extracts of Teak (Tectona grandis) and Dahoma (Piptadeniastrum africanum) and exposed in the field to subterranean termites for 4 months. The effect of these extracts in enhancing the durability of these timbers was studied in accordance with EN 252. Some of the parameters considered were visual characteristics, hardness and weight loss after exposure. The results showed some species to be significantly different in durability between control samples and their treated counterparts (after 4 months) and not in others (after 4 months). Moreover, among the species, durability was high in Pertersianthus macrocarpus while the others followed in the following order: Albizia ferruginea = Blighia sapida = Sterculia rhinopetala > Amphimas pterocarpoides > Sterculia oblonga = Cola gigantean = Antiaris Toxicaria > Canarium schweinfurthii.
A Asamoah, C Antwi-Boasiako


Treatment of Selected Lesser Used Timber Species against Subterranean Termites using Heartwood Extracts from Teak (Tectona grandis) and Dahoma (Piptadeniastrum africanum)
2008 - IRG/WP 08-30476
Lesser used timber species represent a valuable material for all-purpose uses. However, most of them are not durable. They are, for effective utilization, often treated with all manner of toxic synthetic substances to enhance their natural durability, especially in the tropics where conditions favour their deterioration. Most of these toxic synthetic substances often pose a threat to the environment. Currently, one probable measure is to treat low durability timbers with extracts from highly durable ones. Heartwood water extracts of Teak (Tectona grandis) and Dahoma (Piptadeniastrum africanum) were impregnated into ten Ghanaian LUTS and exposed in the field to the ground for 8 months in accordance with European Norm 252. Visual durability ratings, hardness and mass losses were measured in assessing their field performance. Teak extract did less harm or conferred better resistance on LUTS in more instances than Dahoma extract did. The enhanced durability of LUTS was ranked as follows: Albizia ferruginea > Pertersianthus macrocarpus > Blighia sapida > Sterculia rhinopetala > Amphimas pterocarpoides > Cola gigantean > Celtis zenkeri > Sterculia oblonga > Antiaris Toxicaria > Canarium schweinfurthii. Though extracts showed reduced efficacy with time, indications were that extracts from the heartwood of tropical timber species as that of Teak could be employed to preserve their low durability counterparts. Attempts at fixing extracts permanently in timber should be made. The use of natural organic preservatives is promising if it will be deeply researched.
A Asamoah, C Antwi-Boasiako, K Frimpong-Mensah


Moisture content levels and decay of hemlock
1986 - IRG/WP 1287
As a model of decay conditions of wooden members in wooden houses, a decay test was set up in which samples of western hemlock (Tsuga heterophylla) under 4 moisture levels were examined. Each week the samples were weighed and if the weights indicated that their moisture contents were lower than the expected levels, distilled water was added. Every 8 weeks 3 samples from each condition were oven dried at 60°C for 48 hours, up to 48 weeks. After 48 weeks, 3 samples from each condition were oven dried every 16 weeks. The results obtained were as follows: After examining the samples for 96 weeks at 27°C, the mean weight loss of the hemlock samples kept at about 50-100% moisture content level was larger than those of the other levels. If the samples were dried every 8 weeks, the amount of decay in them was not significant. Decay was also not significant in the samples kept at approximately 20-30% moisture content level.
K Suzuki


Summary of development of pile wrappings in Los Angeles Harbour
1987 - IRG/WP 4141
G Horeczko


Loss of preservatives from treated wood during service
1992 - IRG/WP 92-3734
During the 23rd IRG conference in Harrogate the matter of preservative losses from treated wood during service was raised. We were asked to collect information in this field and ask now for help from you. Many tests have been carried out at a laboratory scale to study fixation and leaching from wood treated with different preservatives. Very little, however, is reported on losses of preservatives during service. Since these values are of great relevance regarding environmental impact and the final disposal, reuse or recycling of treated wood, it is of great importance to get as much information as possible on the amount of active ingredients lost during service life. We are convinced there are quite a lot of analytical data and additional information available in many places all over the world. It appears to be rewarding to collect those data and put them together adequately to get an astimate of the losses of the different components based on a broad scale of in service situations. This work will be done as soon as information is available and it is intended to present the results on next IRG meeting.
M-L Edlund, D Rudolph


Effects of acetylation on the dimensional stability and decay resistance of kenaf (Hibiscus cannabinus L.) fiberboard
1996 - IRG/WP 96-40059
The objective of this study was to investigate the influence of the acetylation treated kenaf fiber, Phenol formaldehyde resin content level, and three fungi species on the dimensional stability and decay resistance of high density non wood composition boards. A standard ASTM method was used to evaluate weight loss and thickness change. The linear shrinkage and expansion of each species were also determined. All specimens were exposed to decay chambers for 16 weeks. Test results indicated that most of the main factors significantly influence the thickness, length changes, and decay resistance of the high density kenaf fiberboards.
P Chow, T Harp, R Meimban, J A Youngquist, R M Rowell


Strength loss associated with steam conditioning and boron treatment of radiata pine framing
1987 - IRG/WP 3438
The combined effect of included defects and wood moisture content on the strength loss of second rotation radiata pine framing following conventional steam conditioning is investigated. The green Modulus of Elasticity (MOE) is reduced by approximately 13% after steaming. When dried after steaming, however, neither the MOE nor MOR is significantly different from unsteamed dried controls.
M J Collins, P Vinden


Collaborative soft rot tests: PRL tests of Cu/Cr/As preservative using method of Document No: IRG/WP/208
1973 - IRG/WP 223
These tests were undertaken as a preliminary to the next series of collaborative soft rot tests. An interim report has already been presented at Berlin in 1972 as Document No: IRG/WP/211
J K Carey, J G Savory


On Donkioporia expansa (Desm.) Kotl. & Pouzar
1986 - IRG/WP 1285
Donkioporia expansa is found more often in houses than realised until now. Virulence tests according to EN 113 show not only an attack of oak, but also of other hardwoods and even soft-woods.
G Buchwald


Soil virulence tests using Scots pine sapwood
1973 - IRG/WP 222
Following the tests reported in Document No: IRG/WP/210, in which soils from different laboratories were investigated for virulence, supplementary tests have been carried out using Scots pine sapwood and an extended incubation period.
J K Carey, J G Savory


Comparison of the agar-block and soil-block methods used for evaluation of fungitoxic value of QAC and CCA wood preservatives
1994 - IRG/WP 94-20039
The modyfied agar-block and soil-block methods were used for comparing the fungitoxic value of QAC and CCA type preservatives against Coniophora puteana and Coniophora olivacea The mass loss and moisture contents of wood were analysed.
J Wazny, L J Cookson


The biostatic effect of copper on decay of fire retardant-treated mining timber
1991 - IRG/WP 1507
Blocks of Eucalyptus grandis were treated with 20kg/m³ ammonium sulphate as fire retardant and challenged with Coriolus versicolor. Replicates were soil buried. A second set of blocks was treated with retardant and copper at 6.6 kg/m³ (ie 1% w/w), and challenged similarly. After 8 weeks weight losses produced by Coriolus versicolor in untreated, retardant treated and copper supplemented blocks were 45, 25, and 0% respectively, and corresponding weight losses in soil were 27, 25 and 10%. These results, and electronmicroscopical observations, showed conclusively that Eucalyptus grandis treated with fire retardant was rapidly decayed, and that copper inhibited such decay.
G D Shelver, E A Shelver, A A W Baecker


Temperature influence on the growing velocity and cellulolytic activities of Poria placenta strains from several locations
1986 - IRG/WP 2263
The differences observed on the FPRL 280 Poria Placenta strain at several Research European Laboratories for determining up the fungicide effectiveness of wood preservative has carry us to do a comparative study about the cellulolytic activity and growth velocity of each of this strains at different temperatures (22, 24 and 28°C). The results show significative differences when the temperature is changed.
A M Navarrete, M T De Troya


Evaluation of wood treated with copper-based preservatives for Cu loss during exposure to heat and copper-tolerant Bacillus licheniformis
1999 - IRG/WP 99-20155
Copper-based wood preservatives need to be effective against exposure to all types of microorganisms. Wood treated with six copper-based preservatives was exposed to 121°C and 20 psi pressure for 15 minutes under standard autoclave conditions and the copper-tolerant bacterium, Bacillus licheniformis CC01, for 10 d at 28°C and 150 rpm. Sixteen to 37 percent of the copper was released from the wood during autoclaving, with copper citrate demonstrating the highest percent loss. Forty-four to 82 percent of the copper remaining in the samples following autoclaving was removed during exposure to the bacterium in liquid culture; copper naphthenate in oil and ACQ-D had losses of eighty percent or greater of the remaining copper. The bacterium removed as much or more total copper in 4 of 6 gas-sterilized samples (85-94%) than the cumulative effects of steam-sterilization and the bacterium on treated samples. Copper loss from in-service treated wood compromises the efficacy of copper-based wood preservatives.
D M Crawford, C A Clausen


Collaborative soft rot tests: Interim report on PRL tests of Cu/Cr/As preservative using method of Document No: IRG/WP/208
1972 - IRG/WP 211
Preservative: Tanalith CT.106 - Results obtained with beech are given in the table and indicate a toxic limit of 16.7-19.2 kg/m³ - The initial soil moisture content was adjusted to 27.8% (the water holding capacity). Noticeable drying out has occurred in some of the test bottles.
J G Savory


Contribution to the testing of wood based board material
1982 - IRG/WP 2176
R G Lea


Evaluation of the decay caused by Chaetomium globosum Kunze, in the course of time
1987 - IRG/WP 2288
The main research done on soft rot has been directed to determining, by microscopic study, the different stages of penetration into the wood of the fungi that cause it. On the basis of the information furnished by this research, in this work we have tried to quantify its effect, by evaluating the weight loss caused by Chaetomium globosum Kunce in wood of Pinus sylvestris L. and Fagus sylvatica L. in the course of time. The results obtained corroborate the existence of succesive stages of decay which is shown by large differences in the weight loss.
M T De Troya, A M Navarrete


Proposals for a vermiculite burial soft rot test method
1980 - IRG/WP 283
J G Savory, J K Carey


Performance results of wood treated with CCA-PEG
1986 - IRG/WP 3363
The addition of polyethylene glycol (PEG) to the CCA system has been shown to reduce the surface hardness of poles and ease spur penetration during climbing. This paper addresses the results of tests dealing with preservative retention and penetration, permanence of CCA and PEG, strength, drying rate, and checking characteristics.
W P Trumble, E E Messina


Collaborative soft rot tests: 2nd interim report
1975 - IRG/WP 258
J G Savory, J K Carey


Virulence testing of cultures of different origins of the test fungus Coriolus versicolor strain CTB 863 A
1986 - IRG/WP 2267
The virulence of cultures of different origins of Coriolus versicolor CTB 863 A - a strain which is mentioned in EN 113 - was tested. Standard blocks of beech wood were used at temperatures of 20-22°C and 26-28°C and particleboard was tested at 26-28°C. The decay capacity of the different inoculations varied widely, as could be expected it was greatest at the higher temperature level.
W Kerner


The rate of redistribution and loss of leachable preservatives under service conditions
1993 - IRG/WP 93-30026
This paper describes experiments carried out to determine patterns of preservative redistribution and any associated losses which occur when wood containing unfixed water-soluble wood preservatives is exposed to service conditions where leaching is possible. Scots pine sapwood treated with disodium octaborate was used as a model system. Results are recorded and discussed for trials representing painted joinery out of ground contact and unpainted stakes half buried in the ground. The results indicate that in the painted samples out of ground contact the water-soluble compound was redistributed longitudinally and away from the joint zone during the first months of exposure, although little redistribution occurred laterally. No difference in redistribution patterns could be associated with paint type. Ground contact stakes showed a loss in the water-soluble compound of about 40% in the first six months exposure. Most of this appeared to occur from the surface zones of the stake exposed to the weather, particularly from the extreme top. In addition, the compound appeared to migrate upwards from the below-ground portion of the stake to the above-ground portion. These results provide new information on the extent of movement of water-soluble preservatives in painted, jointed timber out of ground contact and in unpainted timber in ground contact. It is concluded that the long-term significance of the observed redistribution effects for painted joinery should be evaluated to confirm that there is no likelihood of shortcomings in performance in practice. For the ground contact situation, results confirm that rates of redistribution and loss are high enough to indicate inappropriateness of such materials for practical use without associated technologies to reduce mobilities.
R J Orsler, G E Holland


The performance of wood preservatives in soil-bed soft rot tests
1993 - IRG/WP 93-20007
Testing the efficacy of wood preservatives in soil is recognised as a fundamental part of the assessment of long-term wood protection in ground contact. Laboratory based tests can provide a hazardous environment in which a preservative can be challenged by a range of micro-organisms. This paper presents the results of tests carried out to investigate the performance of wood preservatives in a wet soil environment using both strength loss and weight loss as the main criteria for performance assessment.
G R Williams, S Caswell


On the use of % weight loss as a measure for expressing results of laboratory decay experiments
1992 - IRG/WP 92-2394
It is suggested that careful consideration should be given for the presentation of data from laboratory decay experiments, especially when comparisons are being made from experiments involving wood blocks of varying densities. Percent weight loss can be used for comparisons of durability even if wood blocks vary in density. It is suggested that the absolute weight loss for a given volume (g/cm³) is the most appropriate measure for expressing decay rates or decay susceptibility.
T Nilsson, G F Daniel


Termiticidal effectiveness of synthetic pyrethroids, carbaryl and chlordane in wood-block test
1985 - IRG/WP 3356
The results of some wood-block tests with allethrin, permethrin, fenvalerate, carbaryl and chlordane against Coptotermes formosanus are tabled and compared against some organophosphates, chlorpyrifos, fenitrothion, phoxim, tetrachlorvinphos and acephate. The treatment of the wood blocks was exactly as described in Document No: IRG/WP/3330. Among the pyrethroids tested, permethrin was the most effective. However this was not so effective as the organophosphates such as chlorpyrifos, phoxim and tetrachlorvinphos.
K Tsunoda


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