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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 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 Response to Hand Tools Routing & Recessing Sanding Sapwood Color Scientific Name Screwing Staining Steam Bending Strength Properties Texture Toxicity Trade Name Tree Identification Tree Size Turning Varnishing Veneering Qualities		Scientific Name Guarea thompsonii Trade Name Guarea Family Name Meliaceae Common Names Akpaku, Avellano, Black guarea, Bo-in-dah, Bolon, Bosse, Busi, Cedar mahogany, Cedron, Close grained mahogany, Dark bosse, Diambi, Dikunze, Guano blanco, Guarea, Guarea bosse, Hapopeya, Kaffi, Koguibe, Kwabohoro, Lombe, Mietandabo, Mutigbanaga, Mutigbanaye, Nigerian cedar, Nigerian pearwood, Nuguata, Obabonekwi, Obobo, Obobo nekwi, Obobo-nekwi, Obobonekwi, Oboborukin, Ofe, Scented mahogany, Sidu, Sweet cedar, Teninini, Timbi, Tshidiamakeka, Ugbokpo Regions of Distribution Africa Countries of Distribution  [VIEW MAP] Cameroon, Congo, Gabon, Ghana, Ivory Coast, Kenya, Liberia, Niger, Nigeria, Zaire Common Uses Boat building (general), Boat building, Boxes and crates, Cabinetmaking, Canoes, Carvings, Chairs, Chests, Concealed parts (Furniture), Core Stock, Decorative plywood, Decorative veneer, Desks, Dining-room furniture, Dowell pins, Dowells, Drawer sides, Excelsior, Figured veneer, Fine furniture, Floor lamps, Flooring, Furniture , Furniture components, Furniture squares or stock, Furniture, Hatracks, Heavy construction, Joinery, Kitchen cabinets, Lifeboats, Light construction, Living-room suites, Millwork, Mine timbers, Office furniture, Paneling, Plain veneer, Plywood, Poles, Posts, Radio - stereo - TV cabinets, Rustic furniture, Shipbuilding, Stools, Structural plywood, Tables , Turnery, Utility furniture, Utility plywood, Vehicle parts, Veneer, Veneer: decorative, Wardrobes Environmental Profile Status unsure as a result of insufficient information Status unknown in many of its growth areas Generally widespread, secure, and abundant within most of its range Extinct, Endangered, Vulnerable, or Rare in some parts of its natural range Data source is World Conservation Monitoring Center Endangered in Liberia and Vulnerable in Cameroon and Ivory Coast. Its environmental status in the wild is listed as unknown in Gabon, Ghana, Nigeria, and Zaire because of inadequate information Distribution Overview This species is found in Cameroon, Congo, Côte d'Ivoire, Gabon, Ghana, Liberia, Nigeria and Zaire. It is a shade tolerant species found in moist and evergreen forest hillsides. Heartwood Color Brown Red Yellow Purple Black Pink Orange Pale red to pink Reddish brown Pale brown Yellow to golden-yellow to orange Darkens with age Brown Sapwood Color White Yellow Brown Red Green/Grey Well defined Pinkish Paler than heartwood White to yellow Grain Straight Figure Wavy Distinct (figure) Interlocked Closed Even Growth rings (figure) Mottled (figure) Straight Wavy Distinct figure Interlocked Figure shows mottle Clear growth rings (figure) Texture Fine Medium Even or uniform Uniform Very fine Coarse Fine Fine to medium Very fine Medium Luster Medium High Lustrous Pronounced Dull Natural Growth Defects Gum/resin exudation Board surfaces are sometimes sticky due to gum exudation at high temperatures Natural Durability Susceptible to insect attack Resistant to termites Durable Resistant to powder post beetles Moderately durable Non-resistant to termites Non-resistant to powder post beetles Susceptible to attack from powder post (Lyctid & Bostrychid) beetles Moderately resistant to termite (Isoptera) attack Durable Moderately durable Resistant to attack from powder post (Lyctid & Bostrychid) beetles Resistant to attack from termites (Isoptera) Pinworms (ambrosia beetles) are commonly present Very durable Susceptible to attack from termites (Isoptera) Non durable Heartwood moderately resistant to termite attack Odor Has an odor No specific smell or taste Light-Induced Color Change Darker Toxicity Respiratory effects Unspecified toxicity Dermatitic effects Kiln Schedules Drying (speed) is fast UK=E US=T6D2/T3D1 Fr=5 UK=F US=T6D4/T3D3 Fr=6 T6 - D2 (4/4); T3 - D1 (8/4) US Drying Defects Splitting Resin Exudation Distortion Slight surface checking No twisting or warping Slight twist/warp Moderate end spitting Slight end splitting No end splitting Moderate surface checking Expect resin/gum exudation Requires care since the material is liable to split and check during kiln drying. Ease of Drying Fairly Easy Slowly Reconditioning Treatement Gum Exudation Easy Variable results. Requires care Moderate Difficult The timber air-seasons easily, however some care is needed during kiln-drying in order to minimize defects. Kiln Drying Rate Naturally dries slowly Tree Identification Bole/stem form is buttressed Bole/stem form is straight Bole/stem form is cylindrical Bole/stem form is not buttressed Tree Size Bole length is 10-20 m Trunk diameter is 100-150 cm Tree height is 30-40 m Trunk diameter is 150-200 cm Sapwood width is 5-10 cm Bole length is 0-10 m Bole length is 20-30 m Trunk diameter is 200-250 cm Sapwood width is 0-5 cm Boles are often straight, long and well-formed. Product Sources The ITTO reports that the species is an important and regular source of timber for export. Certified Source Certified Source Comments General finishing qualities are rated as good Narrow stock is apt to split in nailing. Splitting Blunting Effect Moderate Little High to severe Blunting effect on machining is slight Cuting edges are dulled moderately Blunting effect on sawing dry wood is mild Blunting effect on machining is moderate Boring Fair to good results Fairly easy to very easy Carving Fair to Good Results Fairly Easy to Very Easy Very good results Cutting Resistance Easy to saw Cutting Resistance with dry wood is easy Low cutting resistance Cutting Resistance with dry wood is difficult Gluing Fairly Easy to Very Easy Fairly Difficult to Very Difficult Poor to Very Poor Results Easy to glue Fair gluing properties Mortising Fairly Easy to Very Easy Fair to Good Results Moulding Fairly Easy to Very Easy Fair to Good Results Fairly Difficult to Very Difficult Movement in Service Excellent Stability - Small Movement Fair to Good Stability - Medium Movement Small Stable The timber is dimensionally stable after seasoning. Nailing Pre-Boring Recommended Fairly Difficult to Very Difficult Fairly Easy to Very Easy Very Good to Excellent Results Fair to Good Results Easy to nail Good nailing qualities Difficult to nail Narrow stock may split. Planing Fairly Easy to Very Easy Fair to Good Results Very Good to Excellent Results Fairly Difficult to Very Difficult Easy to plane Yields clean surfaces Responds very well to both hand and machine tools Material planes, turns, moulds, mortises, and bores to produce relatively smooth surfaces, except in quartersawn stock with interlocked grain which may cause the grain to pick-up Resistance to Impregnation Resistant heartwood Resistant sapwood Permeable sapwood Heartwood is extremely resistant Sapwood is permeable Heartwood is impermeable Response to Hand Tools Easy to Work Responds Readily Easy to machine Difficult to machine Good response to hand tools There may be some pick up in material with interlocked grain. Routing & Recessing Fair to Good Results Fairly Easy to Very Easy Sanding Fairly Easy to Very Easy Fair to Good Results Very Good to Excellent Results Good sanding qualities Screwing Pre-boring recommended Very Good to Excellent Results Fairly Difficult to Very Difficult Fair to Good Results Easy to screw Turning Fairly Easy to Very Easy Fair to Good Results Veneering Qualities Veneers easily Suitable for peeling Suitable for slicing Easy to cut No drying degrade. Dries flat without splitting Steam Bending Moderate Satisfactory Painting Good results Polishing Fair to Good Results Very Good to Excellent Results Fairly Easy to Very Easy Good results Staining Fairly Easy to Very Easy Fair to Good Results Very Good to Excellent Results Finish is generally good Stains well Varnishing Fair to Good Results Fairly Easy to Very Easy Good results Strength Properties Max. crushing strength = high Bending strength (MOR) = medium Bending strength (MOR) = high Hardness (side grain) = soft Modulus of Elasticity (stiffness) = low Modulus of Elasticity (stiffness) = medium Density (dry weight) = 38-45 lbs/cu. ft. Shrinkage, Tangential = small Shrinkage, Volumetric = moderate Shrinkage, Tangential = moderate Shrinkage, Radial = very small Shrinkage, Radial = small Max. crushing strength = medium Shrinkage, Radial = fairly large Shearing strength (parallel to grain) = medium Shearing strength (parallel to grain) = low Toughness-Hammer drop (Impact Strength) = low Hardness (side grain) = medium Density (dry weight) = 31-37 lbs/cu. ft. Shrinkage, Volumetric = small Shrinkage, Tangential = very small Toughness (total work) = very low Toughness (total work) = low Shrinkage, Radial = moderate Modulus of Elasticity (stiffness) = very low Max. crushing strength = low Density (dry weight) = 46-52 lbs/cu. ft. Bending strength (MOR) = very high Bending strength (MOR) = low Numerical Data Item Green Dry English Bending Strength 11926 16327 psi Density 39 lbs/ft3 Hardness 1130 lbs Impact Strength 29 27 inches Maximum Crushing Strength 6249 8930 psi Shearing Strength 1940 psi Stiffness 1552 1712 1000 psi Toughness 130 inch-lbs Work to Maximum Load 7 12 inch-lbs/in3 Specific Gravity 0.38 0.54 Weight 40 38 lbs/ft3 Radial Shrinkage 3 % Tangential Shrinkage 6 % Volumetric Shrinkage 10 % Item Green Dry Metric Bending Strength 838 1147 kg/cm2 Density 624 kg/m3 Hardness 512 kg Impact Strength 73 68 cm Maximum Crushing Strength 439 627 kg/cm2 Shearing Strength 136 kg/cm2 Stiffness 109 120 1000 kg/cm2 Toughness 149 cm-kg Work to Maximum Load 0.49 0.84 cm-kg/cm3 Specific Gravity 0.38 0.54 Weight 641 608 kg/m3 Radial Shrinkage 3 % 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] Bois et Forets des Tropiques,1978,Bosse (Guarea cedrata, Guarea laurentii and Guarea thompsonii,Bois et Forets des Tropiques,No.177,pp35-49 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 Chudnoff, M.,1984,Tropical Timbers of the World,U.S.A. Department of Agriculture, Forest Service, Forest Products,Laboratory, Madison. Cooper, G.P., Record, S.J.,1931,The Evergreen Forests of Liberia,Yale School Forestry Bulletin,31,pp1-153 Cox, H.A.,1939,A Handbook of Empire Timbers,Forest Products Research Laboratory, Princes Risborough Desch, H.E.,1948,The Cedars,Wood 13(2) pp40-3 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. 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 - Comite Nacional des Bois Coloniaux,1931,Etude Physique et Mecanique des Bois Coloniaux,Assoc. Colonies-Sciences & Comite National des Bios Coloniaux, Paris,,France 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. 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 Kinloch, D., Miller, W.A.,1949,Gold Coast Timbers,Govt. Printer Gold Coast 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) Lebacq, L., Dechamps, R.,1967,Contribution a un Inventaire de Forets du Nord-kasai,Musee Royal de L'Afrique Centrale Belgium Annals Series 8 No.5 Lincoln, W.A. 1986. World Woods in Color. Linden Publishing Co. Inc., Fresno, California. Pieters, A.,1977,Essences Forestieres du Zaire,R.U.G. Gent Belguim Rendle, B.J.,1938,Commercial Mahoganies and Allied Timbers,Forest Products Research Laboratory, London Bulletin,No 18 Rendle, B.J.,1969,World Timbers (3 Vols.,Ernest Benn Ltd. London Sallenave, P.,1955,Proprietes Phyiques et Mecaniques des Bois Tropicaux de l'Union Francaise,C.T.F.T 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. Titmuss, F.H.,1965,Commercial Timbers of the World,Technical Press Ltd., London, 3rd edition Unwin, A.H.,1920,West African Forests and Forestry,T. Fisher Unwin Ltd. London Whitmore, T.C.,1973,Tree Flora of Malaya A Manual for Foresters Volume 2,Forest Department Ministry of Primary Industries Malaysia Wood, B., Calnan, D.,1976,Toxic Woods,British Journal of Dermat 94 Suppl. 13