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Blunting Effect Boring Carving 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 Light-Induced Color Change Luster Mortising Moulding Movement in Service Nailing Natural Durability Natural Growth Defects Numerical Data Odor Painting Planing Polishing Product Sources References Regions of Distribution Resistance to Impregnation Resistance to Splitting Response to Hand Tools Routing & Recessing Sanding Sapwood Color Scientific Name Screwing Staining Steam Bending Strength Properties Synonyms Texture Toxicity Trade Name Tree Identification Tree Size Turning Varnishing Veneering Qualities		Scientific Name Nauclea diderrichii Trade Name Opepe Family Name Rubiaceae Synonyms Sarcocephalus trillesii Common Names Abouko, Akondoc, Aloma, Aloua, Asibo, Awesu, Badi, Bedo, Bilinga, Bohia, Bonkangu, Bonkese, Bosema, Bosima, Brimstone, Bundui, Doe-yah, Dubawile, Dunkake, Echinchin, Edjin, Eke, Ekusiawa, Engolo, Eridinda, Etinda, Gluu, Groussou, Gulu, Gulu-maza, Gulumanzi, Ikaka, Issoula, Kantate, Kilingi, Kilu, Kusia, Kusia papa, Kusiaba, Kusiabe, Kusiabo, Kussia, Linzi, Mamoundi, Mokesse, Moukonia, Mtoma, N'gulu, N'gulu maza, N'gulu-maza, Nguebe, Obiache, Odosi, Opepe, Opepi, Owessu, Owoso, Sibo, Sukisia, Tebotue, Toumbo, Uburu, Urherekor, Wei-yidi Regions of Distribution Africa Countries of Distribution  [VIEW MAP] Angola, Cameroon, Congo, Equatorial Guinea, Gabon, Ghana, Guinea, Ivory Coast, Liberia, Nigeria, Sierra Leone, Uganda, Zaire Common Uses Agricultural implements, Boat building (general), Boat building, Boat building: planking, Bridge construction, Building materials, Cabinetmaking, Canoes, Chairs, Charcoal, Chests, Concealed parts (Furniture), Cooperages, Crossties, Decks, Decorative veneer, Desks, Dining-room furniture, Dockwork, Domestic flooring, Dowell pins, Dowells, Drawer sides, Excelsior, Figured veneer, Fine furniture, Floor lamps, Flooring, Flooring: commercial heavy traffic, Flooring: industrial heavy traffic, Framing, Fuelwood, Furniture , Furniture components, Furniture squares or stock, Furniture, Harbor work, Hatracks, Heavy construction, Joinery (external): ground contact, Joinery, Kitchen cabinets, Lifeboats, Light construction, Living-room suites, Marine construction, Millwork, Mine timbers, Moldings, Office furniture, Parquet flooring, Piling, Plywood, Poles, Posts, Radio - stereo - TV cabinets, Railroad ties, Rustic furniture, Shipbuilding, Sporting Goods, Tables, Truck bodies, Turnery, Vehicle parts, Veneer: decorative, Wharf construction Environmental Profile Vulnerable in parts of its natural habitat Rare in parts of its natural range (population is at risk) Generally secure within most of its natural habitat, but note exceptions. Data source is World Conservation Monitoring Center Rare in Ghana and Uganda, Vulnerable in Cameroon Distribution Overview The natural range of the species extends from Sierra Leone to the Congo region and eastward to Uganda. The species usually grows in pure stands. Heartwood Color Brown Pink Red Yellow to golden-yellow to orange Brown Orangish cast Darkens after prolonged exposure Dark brown The heartwood is orange-brown, orange, or golden-yellow in color, with a copper luster, and darkens upon exposure. The striking color of the wood, together with the figure is reported to give it a very attractive appearance. Sapwood Color Brown White to yellow Pinkish Paler than heartwood Well defined Grey Distinct from the heartwood Different than heartwood Grain Figure Interlocked Distinct (figure) Straight Stripe (figure) Closed Even Mottle Rippled (figure) Irregular Interlocked Distinct figure Straight Striped figure Rippled figure Mottled or streaked figure sometimes Irregular Distinct and very fine figure The grain is usually interlocked or irregular, and produces an attractive ribbon or rope figure. Texture Fine Even or uniform Coarse Medium coarse to coarse Medium Luster High Medium Lustrous Medium to high Natural Growth Defects Yellowish deposits in vessels Gum and mineral deposits Natural Durability Perishable Resistant to attack from marine borers Very durable Resistant to attack from termites (Isoptera) Susceptible to attack from powder post (Lyctid & Bostrychid) beetles Resistant to attack from powder post (Lyctid & Bostrychid) beetles Pinworms (ambrosia beetles) are commonly present Moderately resistant to termite (Isoptera) attack Resistant to attack from pinworms (ambrosia beetles) Durable Sapwood susceptible to attack by powder post beetles Heartwood is very durable Good weathering properties Sapwood is moderately resistant to attack by termites in West Africa. Odor Wood has slightly bitter taste Slight fragrant aroma associated with freshly cut wood Freshly-Cut wood has a slightly fragrant aroma, which becomes indistinct when the wood is seasoned Light-Induced Color Change Darker Toxicity Dermatitic effects The wood contains an alkaloid that is toxic to some individuals. Kiln Schedules UK=E US=T6D2/T3D1 Fr=5 Dry at a slow speed Drying (speed) is fast T6 - D2 (4/4); T3 - D1 (8/4) US Schedule E; United Kingdom Kiln Drying Rate (in days) is rather slow Drying Defects Collapse Checking Internal Honeycombing Possible Severe surface checking Severe end splitting Slight surface checking Moderate end spitting Slight twist/warp No twisting or warping Moderate surface checking Slight end splitting Surface checks No surface checking No end splitting Expect splits Distortion (twist/warp) is likely Quartersawn material dries with very little checking or distortion, but flat sawn timber tends to be refractory and may surface-check, split and distort during drying. Ease of Drying Variable Requires special attention Difficult Moderate Figure Occurrence is variable Quartersawn stock dries well, but backsawn material can be refractory. Thin stickers and end protection are advisable Kiln Drying Rate Slow (18-28 days for boards < 32 mm, to 52-84 days for boards >= 63 mm) Tree Identification Bole/stem form is not buttressed Bole/stem form is cylindrical Bole/stem form is straight Bole/stem form is buttressed Tree Size Bole length is 0-10 m Tree height is 30-40 m Tree height is 40-50 m Tree height is 50-60 m Trunk diameter is 100-150 cm Product Sources The ITTO reports that timber from this species is produced in rather low quantities. The timber is currently being promoted for export. Supplies are plentiful, and good sized material of excellent quality is readily available at fairly expensive prices. Comments Abnormal Growth Defects General finishing qualities are rated as good Hidden defects such as reddish granular stones or heart shakes may be present. Blunting Effect Moderate Blunting effect on machining is moderate Blunting effect on machining is slight Blunting effect on sawing dry wood is moderate Medium dulling effect on cutting edges Boring Fair to good results Fairly easy to very easy Fairly easy with ordinary tools Difficult Carving Fair to Good Results Fairly Easy to Very Easy Fair carving characteristics Cutting Resistance Fairly Difficult to Very Difficult to saw Cutting Resistance with dry wood is easy Moderate to fairly difficult to saw Cutting Resistance with dry wood is moderate Slow feeding rates and 17 degree cutting angles are recommended for best results. Gluing Fair to Good Results Easy to glue Satisfactory gluing properties Mortising Fair to Good Results Fairly Easy to Very Easy Material mortises fairly easily Moulding Fair to Good Results Fairly Easy to Very Easy Good moulding properties Movement in Service Fair to Good Stability - Medium Movement Excellent Stability - Small Movement Small Stable Nailing Fair to Good Results Possible if prebored Easy to nail Difficult to nail Holds nails well There is a slight tendency for the timber to split in nailing Planing Fair to Good Results Fairly Easy to Very Easy Easy to plane Special attention required Responds well to ordinary tools in mortising Difficult to plane A reduced planing angle of 10 degrees is recommended in quartersawn material to prevent pick-up Resistance to Impregnation Permeable sapwood Resistant heartwood Resistant sapwood Heartwood is moderately resistant Sapwood is permeable Heartwood is somewhat permeable Resistance to Splitting Poor Response to Hand Tools Responds Readily Easy to machine Moderate working qualities Fair response to hand tools Routing & Recessing Fair to Good Results Fairly Easy to Very Easy Routing is difficult Fair routing properties Sanding Fair to Good Results Fairly Easy to Very Easy Good sanding finish Easy to sand Screwing Fair to Good Results Fairly Easy to Very Easy Easy to screw Screwing yields good results The wood takes screws rather well. Turning Very Good to Excellent Results Fairly Easy to Very Easy Easy to turn Veneering Qualities Suitable for slicing There is slight to moderate drying degrade and the potential for buckles and splits Moderately easy to veneer Good gluing qualities Bolt preparation requires steaming Steam Bending Fair to Good Results Very Good to Excellent Results Very poor Poor Moderate Painting Satisfactory results Polishing Fair to Good Results Satisfactory results Good results Requires a filler Staining Fair to Good Results Very Good to Excellent Results Finish is generally satisfactory Finish is generally good Varnishing Varnishes fairly well Satisfactory Strength Properties Max. crushing strength = high Density (dry weight) = 46-52 lbs/cu. ft. Hardness (side grain) = medium Modulus of Elasticity (stiffness) = medium Bending strength (MOR) = high Shearing strength (parallel to grain) = medium Bending strength (MOR) = medium Shrinkage, Tangential = moderate Shrinkage, Radial = moderate Shrinkage, Volumetric = fairly large Shrinkage, Volumetric = moderate Shrinkage, Tangential = small Shrinkage, Tangential = fairly large Shrinkage, Radial = small Shrinkage, Tangential = very small Shrinkage, Radial = very small Shearing strength (parallel to grain) = low Max. crushing strength = medium Shrinkage, Volumetric = large Shrinkage, Radial = large Modulus of Elasticity (stiffness) = low Modulus of Elasticity (stiffness) = high Hardness (side grain) = hard Shrinkage, Tangential = large Shrinkage, Radial = fairly large Hardness (side grain) = very hard Hardness (side grain) = soft Density (dry weight) = 38-45 lbs/cu. ft. Work to Maximum Load = very low Shearing strength (parallel to grain) = very low Shearing strength (parallel to grain) = high Max. crushing strength = very high Density (dry weight) = 53-60 lbs/cu. ft Bending strength (MOR) = very high Bending strength (MOR) = low The wood has good wearing properties, and its strength properties are reported to compare favorably with most imports. Density, strength and other properties of the species vary with site, but the wood is generally moderately hard and heavy. The species is 15 to 20 percent stronger than Teak (Tectona grandis) Numerical Data Item Green Dry English Bending Strength 12606 17666 psi Density 47 lbs/ft3 Hardness 1724 lbs Impact Strength 31 29 inches Maximum Crushing Strength 6954 9873 psi Shearing Strength 2118 psi Stiffness 1783 2034 1000 psi Work to Maximum Load 5 9 inch-lbs/in3 Specific Gravity 0.54 0.65 Weight 47 46 lbs/ft3 Radial Shrinkage 4 % Tangential Shrinkage 7 % Volumetric Shrinkage 12 % Item Green Dry Metric Bending Strength 886 1242 kg/cm2 Density 753 kg/m3 Hardness 782 kg Impact Strength 78 73 cm Maximum Crushing Strength 488 694 kg/cm2 Shearing Strength 148 kg/cm2 Stiffness 125 143 1000 kg/cm2 Work to Maximum Load 0.35 0.63 cm-kg/cm3 Specific Gravity 0.54 0.65 Weight 753 737 kg/m3 Radial Shrinkage 4 % Tangential Shrinkage 7 % 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] Bois et Forets des Tropiques,1956,Bilinga,Bois et Forets des Tropiques 47,pp11-14 Bois et Forets des Tropiques,1975,Bilinga,Bois et Forets des Tropiques,160,pp33-46 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 Bond, C.W.,1950,Colonial Timbers,Sir Issac Pitman & Sons Ltd. London 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 Chudnoff, M.,1984,Tropical Timbers of the World,U.S.A. Department of Agriculture, Forest Service, Forest Products,Laboratory, Madison. Cox, H.A.,1939,A Handbook of Empire Timbers,Forest Products Research Laboratory, Princes Risborough 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.,1945,A Handbook of Empire Timbers,Department of Scientific and Industrial Research Forest Products Research Forests Products Research Laboratory, U.K.,1956,A Handbook of Hardwoods,Forest Products Research Laboratory, Princes Risborough, Department of,Science and Industrial Research, Building Research Establishment Fouarge, J.,1950,Appropriation de Bois Congolais aux Besoins de la Metropole,I.N.E.A.C. Belgium Serie Technique,No.38 Fouarge, J.,1953,Bois du Congo,I.N.E.A.C. Fougerousse, M., Deschamps, P.,1968,Essais de Resistance de quelques Bois Tropicaux aux Xylophages Marins dans,la,Port de la Pallice,C.T.F.T. Note Technique,No.7 France - C.T.F.T.,1966,Bois Tropicaux,C.T.F.T. Publ.,12 France - C.T.F.T.,1977,Promotion of African Timbers - New Species,CTFT,35 Leaflets France - Comite Nacional des Bois Coloniaux,1931,Etude Physique et Mecanique des Bois Coloniaux,Assoc. Colonies-Sciences & Comite National des Bios Coloniaux, Paris,,France Ghana - Timber Marketing Board,1969,Ghana Hardwoods,Timber Marketing Board 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 Hedin, L.,1930,Etude sur la Foret et les Bois du Cameroun,Haut-Commissaire de la Cameroun HMSO. 1972. Handbook of Hardwoods. 2nd Edition. Revised by R.H. Farmer. Department of the Environment, Building Research Establishment, Princes Risborough Laboratory, Princes Risborough, Aylesbury, Buckinghamshire. Hughes, J.F.,1971,The Principal Timber Trees of Cameroon,Unpublished data 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 Irvine, F.R.,1961,Woody Plants of Ghana,O.U.P. London 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. ITTO. New Marketable Species Technical Notes. Prepared by Centre Technique Forestier Tropical (CTFT, Division of CIRAD, 45 bis, Avenue de la Belle Gabrielle, 94736 Nogent-sur-marne Cedex, France Jay, B.A.,1968,Timbers of West Africa,TRADA, Red Booklet Series Keay, R.W.J.,1964,Nigerian Trees Vol.2,Nigeria Federal Department of Forest Research, Ibadan Kennedy, J.D.,1936,Forest Flora of Southern Nigeria,Government Printer Lagos Kinloch, D., Miller, W.A.,1949,Gold Coast Timbers,Govt. Printer Gold Coast Kline, M. 1983. Nauclea diderrichii - Opepe. In A Guide to Useful Woods of the World. Flynn Jr., J.H., Editor. King Philip Publishing Co., Portland, Maine. 1994. Page 241-242. Kloot, N.H., Bolza, E.,1961,Properties of Timbers Imported into Australia,C.S.I.R.O. Forest Products Division Technological Paper,No.12 Kryn, J.M., Forbes, E.W.,1959,The Woods of Liberia,U.S.A. Department of Agriculture,Forest Products Laboratory, Madison,,Report No. 2159 Kukachka, B.F.,1970,Properties of Imported Tropical Woods,Forest Research Paper FPL 125 Lavers, G. M. 1966. The Strength Properties of Timbers. Forest Products Research Bulletin, No. 50. Ministry of Technology, Her Majesty's Stationery Office, London. Lavers, G.M.,1983,The Strength Properties of Timber (3rd ed. revised Moore G.L.,Forest Products Research Laboratory, Princes Risborough, Building Research,Establishment Report (formerly Bulletin No.50) Lincoln, W.A. 1986. World Woods in Color. Linden Publishing Co. Inc., Fresno, California. Meniaud, J., Bretonnet, F.,1926,Les Bois Coloniaux d'Afrique dans l'Industrie,Publ. de l'Agence Gen. des Colonies Okigbo, L.,1965,Air Seasoning of Opepe (Nauclea diderrichii) pole and its pressure,impregnation at high moisture content,Nigeria Fed. Department of Forest Research, Ibadan Forest Products,Research Laboratory Report, No.4 Organisation for European Economic Co-operation,1951,African Tropical Timber (Nomenclature, Description,OEEC Patterson, D.,1988,Commercial Timbers of the World, 5th Edition,Gower Technical Press Pieters, A.,1977,Essences Forestieres du Zaire,R.U.G. Gent Belguim Rendle, B.J.,1969,World Timbers (3 Vols.,Ernest Benn Ltd. London Revue des Bois et de ses Applications,1956,Bilinga,Revue des Bois et de ses Applications,11(12,p38 Sallenave, P.,1955,Proprietes Phyiques et Mecaniques des Bois Tropicaux de l'Union Francaise,C.T.F.T Sallenave, P.,1964,Proprietes Physiques et Mecaniques des Bois Tropicaux (Premier Supplement,C.T.F.T. Publ.,no.23 Savill, P.S., Fox, J.E.D.,1967,Trees of Sierra Leone 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.,1959,Survey of Africa Woods 4,Tropical Woods 17(110) pp42-115 Streets, R.J.,1962,Exotic Forest Trees in the British Commonwealth,Clarendon Press Oxford T.R.A.D.A.,1982,Timbers for river and sea constructions,TRADA Wood Information Section 0, Sheet 6 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 Tanzania Forest Division,1966,Diospyros mespiliformis (African Ebony,Tanzania Forest Div. Util. Sec. Moshi - Timbers of Tanganyika Taylor, C.J.,1960,Synecology and Silviculture in Ghana,University College of Ghana Thomas Nelson and Sons Thomas, A.V.,1964,Timbers Used in the Boat Building Industry A Survey,Department of Scientific and Industrial Research Forest Products Research,Laboratory Timber Development Association Ltd.,1955,World Timbers (3 Vols.,Timber Development Association Ltd. Uganda Forest Department,1954,Flooring Timbers,Uganda Forest Department Timber Leaflet,No.17 Voorhoeve, A.G.,1965,Liberian High Forest Trees,Centre for Agric. Publishing and Documentation, Wageningen Wood, B., Calnan, D.,1976,Toxic Woods,British Journal of Dermat 94 Suppl. 13