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Blunting Effect Boring Carving Certified Source Comments Common Names Common Uses Countries of Distribution Cutting Resistance Distribution Overview Drying Defects Ease of Drying Environmental Profile Family Name Gluing Grain Heartwood Color Kiln Drying Rate Kiln Schedules Luster Mortising Moulding Movement in Service Nailing Natural Durability Natural Growth Defects Numerical Data Odor Planing Polishing Product Sources References Regions of Distribution Resistance to Impregnation Response to Hand Tools Routing & Recessing Sanding Sapwood Color Scientific Name Screwing Silica Content Staining Steam Bending Strength Properties Texture Toxicity Trade Name Tree Identification Tree Size Turning Varnishing Veneering Qualities		Scientific Name Aucoumea klaineana Trade Name Gaboon Family Name Burseraceae Common Names Acoume, Angouma, Bengouma, Cape Lomez mahogany, Combogala, Gaboon, Gaboon mahogany, Gaboon wood, Koumi, M'goumi, Mofoumou, Moukoumi, N'goumi, N'koum, N'koumi, N'kumi, Ojoume, Okoume, Ongoumi, Uume, Zouga Regions of Distribution Africa Countries of Distribution  [VIEW MAP] Congo, Equatorial Guinea, Gabon Common Uses Artificial limbs, Blockboard, Boat building (general), Boxes and crates, Building construction, Building materials, Cabinetmaking, Canoes, Carvings, Cigar boxes, Construction, Cooperages, Decorative plywood, Decorative veneer, Figured veneer, Fine furniture, Flooring, Furniture , Furniture components, Furniture, Interior construction, Interior trim, Joinery, Light construction, Millwork, Moldings, Musical instruments, Paneling , Paneling, Particleboard, Plywood corestock, Plywood, Pulp/Paper products, Tool handles, Turnery, Vats, Vehicle parts, Veneer, Veneer: decorative Environmental Profile Vulnerable Endangered Abundant/Secure Generally secure within most of its natural habitat, but note exceptions. Endangered within most of its growth range (and may soon be Extinct if adverse environmental practices persist) Distribution Overview The distribution of Okoumé is limited to the West and the Center of Gabon and some small surfaces in Guinea Equatoriale, in Congo and Cameroun. One finds this species between 0 and 700 meters of altitude in forests of leafy trees of plains. Aucoumea klaineana is one of the most abundant species in the Ombrophilous type of forest, in particular in old secondary forests on well drained sites. Heartwood Color Red Pink Brown Purple Pale red to pink Reddish brown Pale brown Salmon pink to light pinkish brown, or reddish brown Light exposure brings gradual change to color Eventually attains an appearance similar to the mahoganies Brown Sapwood Color White Brown Red Yellow Grey Paler than heartwood White to yellow Different than heartwood White or pale gray when freshly cut Well defined Not always clearly demarcated from heartwood Grain Straight Wavy Interlocked Figure Weak (figure) Closed Even Distinct (figure) Stripe (figure) Mottled (figure) Straight Wavy Interlocked Weak figure Striped figure Mottled figure May be wavy or curly Interlocked slightly to moderately Distinct figure Distinct and fine figure Striped or mottled figure on quarter-sawn surfaces. Texture Medium Fine Coarse Medium Fine Coarse Medium to coarse Medium or moderately fine texture Fine to medium Luster Medium High Lustrous Pronounced High and satiny luster Natural Growth Defects Large Gaboon logs sometimes have a brashy core Cross-shakes or thunder shakes are rather common Brittleheart is often frequent and extensive Natural Durability Susceptible to insect attack Non-resistant to termites Non-durable Moderately durable Resistant to powder post beetles Non-resistant to marine borers Non-resistant to powder post beetles Perishable Susceptible to attack from termites (Isoptera) Non durable Resistant to attack from powder post (Lyctid & Bostrychid) beetles Moderately durable Susceptible to marine borer attack Susceptible to attack from powder post (Lyctid & Bostrychid) beetles Very little natural resistance to decay in ground contact Susceptible to attack by marine borers Sapwood susceptible to attack by powder post beetles Sapwood is susceptible to wood staining fungal attack Logs are susceptible to forest longhorn beetle attack Odor No specific smell or taste Silica Content High Siliceous Likely to have significant impact on machining Contains significant silica (up to .25% of dry weight) Toxicity Some toxic effects Dermatitic effects Kiln Schedules UK=E US=T6D2/T3D1 Fr=5 Drying (speed) is fast T6-D4(4/4);T3-D1(8/4) US Schedule E; United Kingdom Kiln Drying Rate (in days) is rather slow Drying Defects Splitting Distortion Checking Slight twist/warp Slight end splitting Moderate end spitting Slight tendency to distort and check No twisting or warping No surface checking Ease of Drying Fairly Easy Medium to High Shrinkage Rapidly Reconditioning Treatement Easy Medium shrinkage Dries rapidly and well, with little degrade or defect Kiln Drying Rate Naturally dries quickly Slow Drying rate is slow Slow (18-28 days for boards < 32 mm, to 52-84 days for boards >= 63 mm) Tree Identification Bole/stem form is buttressed Bole/stem form is cylindrical Bole/stem form is straight Tree Size Trunk diameter is 150-200 cm Trunk diameter is 100-150 cm Bole length is 20-30 m Sapwood width is 0-5 cm Sapwood width is 5-10 cm Tree height is 30-40 m Trunk diameter is 200-250 cm Tree height is 40-50 m Tree height is 50-60 m Tree height is 60-70 m Bole length is 10-20 m Bole length is 30-40 m Trunk diameter is 250-300 cm It usually produces a slightly curved but cylindrical bole that is clear of branches to 70 feet (21 m) and above Product Sources The timber is rather plentiful within its growth range, but supplies, especially in the lumber form, are very limited on the U.S. Market. When available it is priced in the expensive range. 1-inch (2.5 cm) thick boards are reported to cost about US$9.00 per board foot, and veneer for marquetry costs about US$1.25 per square foot (Source - Wood and Wood Magazine, August, 1995). The ITTO reports that a fairly important source of timber. It is exported at a low but regular rate. Certified Source Certified Source Comments Gaboon is similar in strength to Poplar (Populus), though it splits more easily General finishing qualities are rated as good Generally weak and of low density. Blunting Effect High to severe Moderate Little Blunting effect on machining is fairly severe Blunting effect on machining is severe Blunting effect on machining is moderate Moderate to severe blunting effect on tools Blunting effect on sawing dry wood is mild Boring Fair to good results Fairly easy to very easy Carving Fair to Good Results Fairly Easy to Very Easy Cutting Resistance Fairly Difficult to Very Difficult to saw Easy to saw Moderate to saw Cutting Resistance with dry wood is difficult Responds satisfactorily to cross-cutting and narrow bandsawing Cutting Resistance with green wood is moderate Cutting Resistance with green wood is difficult Cutting Resistance with dry wood is easy Gluing Fairly Easy to Very Easy Fair to Good Results Easy to glue Good gluing properties Mortising Fair to Good Results Fairly Easy to Very Easy Moulding Fair to Good Results Fairly Easy to Very Easy Movement in Service Fair to Good Stability - Medium Movement Excellent Stability - Small Movement Small Seasoned wood moves moderately after manufacture Medium Fair dimensional stability Nailing Fairly Easy to Very Easy Fair to Good Results Very Good to Excellent Results Easy to nail Nailed satisfactorily without pre-boring Good nailing characteristics Planing Fairly Difficult to Very Difficult Poor to Very Poor Results Fairly Easy to Very Easy Fair to Good Results Works fairly easily with both hand and machine tools Worked surfaces tend to be wooly Reduced cutting angle of 20 degrees is recommended in planing to prevent tearing Planes to a poor finish Difficult to plane Resistance to Impregnation Resistant heartwood Resistant sapwood Heartwood is resistant Responds poorly to perservative treatment Heartwood is moderately resistant Response to Hand Tools Easy to Work Fairly Difficult to Difficult to Work Easy to machine Difficult to machine Routing & Recessing Fair to Good Results Fairly Easy to Very Easy Sanding Fair to Good Results Very Good to Excellent Results Fairly Easy to Very Easy Satisfactory sanding properties Good sanding finish Screwing Very Good to Excellent Results Fair to Good Results Turning Fairly Easy to Very Easy Fair to Good Results Very Good to Excellent Results Good results Easy to turn Veneering Qualities Suitable for peeling Veneers easily Suitable for slicing Veneers moderately easy Difficult to veneer Easy to cut There is slight to moderate drying degrade and the potential for buckles and splits Suitable for slicing Suitable for peeling Sliced into decorative veneers for paneling and cabinets Rotary cut for laminated work Moderately easy to veneer Steam Bending Poor to Very Poor Results Fairly Difficult to Very Difficult Poor steam bending characteristics Polishing Fair to Good Results Very Good to Excellent Results Satisfactory results Good results Polishes to a lustrous surface Staining Fair to Good Results Poor to Very Poor Results Very Good to Excellent Results Fairly Easy to Very Easy Finish is generally good Stains satisfactorily after surface preparation Poor results Varnishing Fair to Good Results Fairly Easy to Very Easy Satisfactory varnishing qualities Strength Properties Bending strength (MOR) = low Modulus of Elasticity (stiffness) = very low Density (dry weight) = 23-30 lbs/cu. ft. Shearing strength (parallel to grain) = very low Hardness (side grain) = very soft Shrinkage, Volumetric = moderate Shrinkage, Tangential = small Max. crushing strength = medium Max. crushing strength = low Bending strength (MOR) = medium Shrinkage, Radial = moderate Shrinkage, Radial = small Shrinkage, Radial = fairly large Max. crushing strength = high Density (dry weight) = 31-37 lbs/cu. ft. Shrinkage, Tangential = moderate Hardness (side grain) = soft Weak Very low stiffness Surfaces may dent or scratch easily Soft Shrinkage, Volumetric = small Shrinkage, Tangential = fairly large Low in density Hardness (side grain) = medium Density (dry weight) = 15-22 lbs/cu. ft. Crushing strength = medium Bending strength in the air-dried condition (about 12% moisture content) is medium, but lower than Mahogany, and much lower than White oak. strength properties similar to those of Poplar (Populus). It splits more easily than Poplar. Numerical Data Item Green Dry English Bending Strength 6823 10299 psi Density 27 lbs/ft3 Hardness 431 lbs Maximum Crushing Strength 3809 5405 psi Shearing Strength 935 psi Stiffness 1017 1181 1000 psi Specific Gravity 0.33 0.39 Weight 25 22 lbs/ft3 Radial Shrinkage 4 % Tangential Shrinkage 6 % Volumetric Shrinkage 10 % Item Green Dry Metric Bending Strength 479 724 kg/cm2 Density 432 kg/m3 Hardness 195 kg Maximum Crushing Strength 267 380 kg/cm2 Shearing Strength 65 kg/cm2 Stiffness 71 83 1000 kg/cm2 Specific Gravity 0.33 0.39 Weight 400 352 kg/m3 Radial Shrinkage 4 % Tangential Shrinkage 6 % References Banks, C.H., Schoeman, J.P., Otto, K.P.,1977,The Mechanical Properties of Timbers with particular reference to South,Africa,South African Forestry Research Institute Bulletin,(Ed.,Schoeman, J.P. 1973 & Otto K.P. 1976,No.48 Banks, C.H.,1954,The Mechanical Properties of Timbers with Particular Reference to those,grown in the Union of South Africa,Journal of the South African Forestry Association,No. 24 pp.44-65,[South,African Forestry Journal] Becking, R.W.,1960,A Summary of Information on Aucoumea klaineana,Forestry Abstracts,21(2, pp163-72 Bois et Forets des Tropiques,1951,Okoume,Bois et Forets des Tropiques,18-19,pp147-150 Bolza, E., Keating, W.G.,1972,African Timbers - the Properties, Uses and Characteristics of 700 Species,C.S.I.R.O. Div. of Building Research Bolza, E.,1976,Timber and Health,Div. Building Res. C.S.I.R.O. Australia Brown, W.H.,1969,Properties and uses of Tropical hardwoods in the United Kingdom. Part 1,Nonstructural properties and uses.,Conference on Tropical hardwoods SC-5/TN-5, Syracuse University Brown, W.H.,1978,Timbers of the World No.1 Africa,TRADA, Red Booklet Series Brush, W.D.,1944,Foreign Woods - Okoume (Aucoumea klaineana,U.S.A. Department of Agriculture Forest Service Chudnoff, M.,1984,Tropical Timbers of the World,U.S.A. Department of Agriculture, Forest Service, Forest Products,Laboratory, Madison. Clifford, N.,1953,Commercial Hardwoods - Their Characteristics Identification and,Utilization,Sir Isaac Pitman & Sons Ltd. London Collardet, J.,1929,Okoume (Aucoumea klaineana Pierre,Tropical Woods,3(17, PP1-5 Erfurth, T., Rusche, H.,1976,The Marketing of Tropical Wood A. Wood Species from African Moist Forests,F.A.O. Forestry Department Farmer, R.H.,1972,Handbook of Hardwoods,HMSO Forest Products Research Laboratory, U.K.,1955,Kiln-Drying Schedules,Forest Products Research Laboratory, Princes Risborough, Department of,Science and Industrial Research, Building Research Establishment Leaflet,No.42 Fortin, Y., Poliquin, J.,1976,Natural Durability and Preservation of 100 Tropical African Woods,International Development Research Centre, Canada France - C.T.F.T./C.T.B.,1982,Guide pour le Choix des Essences Deroulables-pour la fabrication du,contreplaque,C.T.F.T./C.T.B. France France - C.T.F.T.,1966,Bois Tropicaux,C.T.F.T. Publ.,12 France - C.T.F.T.,Resultats des Observations et des essais effectues au CTFT sur L'Okoume,C.T.F.T., No101 Fuster Riera, P.,1947,Primera Contribucion al Conocimiento de las Maderas de la Guinea,Continental Espanola. (first contribution to a knowledge of timbers from,Spanish Guinea.,Inst. de Estudios Africanos y de la Direccion General de Marruecos y,Colonias, Madrid,pp250 Gutierrez Oliva, A., Plaza Pulgar, F.,1967,Caracteristicas fisico-mecanicas de las maderas Espanolas. (Physical and,mechanical properties of Spanish timbers.,Min.Agric./Dir.Gen Montes/Instituto Forestral de Investigaciones,y,Experiencias, Madrid pp102 Harrar, E.S.,1942,Some Physical Properties of Modern Cabinet Woods 3. Directional and Volume,Shrinkage,Tropical Woods,9(71, pp26-32 HMSO. 1981. Handbook of Hardwoods, 2nd Edition. Revised by R.H. Farmer. Department of the Environment, Building Research Establishment, Princes Risborough Laboratory, Princes Risborough, Aylesbury, Buckinghamshire. Howard, A.L.,1948,A Manual of Timbers of the World.,Macmillan & Co. Ltd. London 3rd ed. I.U.F.R.O.,1973,Veneer Species of the World,Assembled at F.P.L. Madison on behalf of I.U.F.R.O. Working Party on,Slicing and Veneer Cutting ITTO. 1986. Tropical Timber Atlas, Volume 1 - Africa. International Tropical Timber Organization (ITTO) and Centre Technique Forestier Tropical (CTFT, 45bis, Avenue de la Belle Gabrielle, Nogent-sur-Marne Cedex, France. Jane, F.W.,1953,The Structure of World Timbers - 18 Gaboon, Canarium and Dhup,Timber Technology (formerly Timber News,61(2166) Jay, B.A.,1968,Timbers of West Africa,TRADA, Red Booklet Series Kaiser, Jo-Ann. Wood of the Month. Gaboon: The Strong Lightweight from Africa. Wood & Wood Products, November, 1992, Page 54. Kloot, N. H. and E. Bolza. 1961. Properties of Timbers Imported into Australia. Technological Paper No. 12. Division of Forest Products, Commonwealth Scientific and Industrial Organization, Melbourne, Australia. Kloot, N.H., Bolza, E.,1961,Properties of Timbers Imported into Australia,C.S.I.R.O. Forest Products Division Technological Paper,No.12 Kribbs, D.A. 1959. Commercial Foreign Woods on the American Market. Buckhout Lab., Dept. of Botany, The Pennsylvania State University, University Park, Pennsylvania. Kribs, D.A.,1950,Commercial and Foreign Woods on the American Market (a manual to their,structure, identification, uses and distribution,U.S.A. Penn. State College, Tropical Woods Laboratory Kukachka, B.F.,1962,Characters of Some Imported Woods,U.S.A. Department of Agriculture, Forest Products Laboratory, Madison,,Foreign Wood Series,No.2242 Kukachka, B.F.,1970,Properties of Imported Tropical Woods,Forest Research Paper FPL 125 Lincoln, W. A. 1986. World Woods in Color. Linden Publishing Co. Inc., Fresno, California. Nairn, P.M., Editor. 1936. Wood Specimens - 100 Reproductions in Color - A Series of Selected Timbers Reproduced in Natural Color with Introduction and Annotations by H.A. Cox. The Nema Press, Proprietors of Wood, London. Organisation for European Economic Co-operation,1951,African Tropical Timber (Nomenclature, Description,OEEC Patterson, D. 1988. 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Species,Journal of the South African Forestry Association,No.19,pp18-62,[South,African Forestry Journal] Spalt, H.A., Stern, W.L.,1956,Survey of Africa Woods 2,Tropical Woods 16(106) pp65-97 Spalt, H.A., Stern, W.L.,1956,Survey of African woods 1,Tropical Woods,115(105,pp 13-38 Spalt, H.A., Stern, W.L.,1957,Survey of Africa Woods 3,Tropical Woods 16(107) pp92-128 Takahashi, A.,1978,Compilation of Data on the Mechanical Properties of Foreign Woods (Part,III) Africa,Shimane University, Japan, Research Report on Foreign Wood No. 7 Timber Development Association Ltd.,1955,World Timbers (3 Vols.,Timber Development Association Ltd. Timber Development Association,1948,Some New Timbers and Their Uses No. 34,Timber Development Association Limited, London [TRADA] U.A.C.O. Timber Review,1971,Some Straight forward information about a very strong and very durable,wood,U.A.C.O. Timber Review,20,pp12-3 U.S.D.A. Forest Service,1952,Foreign Woods Imported into the U.S.,F.P.L. Madison Rep., No. R1903-12 U.S.D.A. Forest Service,1974,Wood Handbook,U.S.A. Department of Agriculture, Forest Service Handbook,72 USDA. 1987. Wood Handbook - Wood as an Engineering Material. United States Department of Agriculture, Forest Service, Agriculture Handbook No. 72, Forest Products Laboratory, Madison, Wisconsin. Wagenfuhr, H.,1968,Okoume,Holztechnoligie,9(3, pp199-200 WCMC. 1992. Conservation Status Listing - Trees and Timbers of the World. World Conservation Monitoring Center-Plants Programme, Cambridge, CB3 ODL, United Kingdom. Wood, B., Calnan, D.,1976,Toxic Woods,British Journal of Dermat 94 Suppl. 13