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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

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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 Okoum� 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
ItemGreenDryEnglish
Bending Strength682310299psi
Density27lbs/ft3
Hardness431lbs
Maximum Crushing Strength38095405psi
Shearing Strength935psi
Stiffness101711811000 psi
Specific Gravity0.330.39
Weight2522lbs/ft3
Radial Shrinkage4%
Tangential Shrinkage6%
Volumetric Shrinkage10%
ItemGreenDryMetric
Bending Strength479724kg/cm2
Density432kg/m3
Hardness195kg
Maximum Crushing Strength267380kg/cm2
Shearing Strength65kg/cm2
Stiffness71831000 kg/cm2
Specific Gravity0.330.39
Weight400352kg/m3
Radial Shrinkage4%
Tangential Shrinkage6%

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. Commercial Timbers of the World. Fifth Edition. Gower Technical Press, Aldershot, UK. ix + 339 pp.

Patterson, D.,1988,Commercial Timbers of the World, 5th Edition,Gower Technical Press

Rendle, B.J.,1969,World Timbers (3 Vols.,Ernest Benn Ltd. London

Sallenave, P.,1971,Proprietes Physiques et Mecaniques des Bois Tropicaux (Deuxieme,Supplement,C.T.F.T.

Scott, M.H.,1950,Notes on the more Important African Timbers Imported into the Union with,Special Ref. to Port. E.A. 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








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