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Clicking any heading in the main data area (at right) will scroll the page back to this top position. Use the following links to jump to the associated section in the main data. 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