Bombax spp.

Bombax

Family: Bombacaceae

Other Common Names: Alone, Ogoumalanga (Gabon), Msufi-mwitu, Mfume (Tanzania), Megu

(Mozambique), Kapokier (Senegal).

Distribution: West Africa and extending eastward into Tanzania; found in savanna and secondary forests as well as dense rain forests.

The Tree: Height ranges 80 to 120 ft, bole straight and cylindrical; trunk diameters 4 to 6 ft., some species buttressed.

The Wood:

General Characteristics: Heartwood pale reddish brown, yellowish brown, or light brown with a purplish tint, sometimes with darker markings; sapwood whitish, not always sharply differentiated. Texture medium to coarse; grain usually straight; without luster; sometimes with gum veins.

Weight: Basic specific gravity (ovendry weight/green volume) about 0.40; air-dry density 30 pcf.

Mechanical Properties: (First set of data based on the 2-in. standard, second and third sets on the 2-cm standard.)

Moisture content Bending strength Modulus of elasticity Maximum crushing strength

(%) (Psi) (1,000 psi) (Psi)

Green (4) 4,310 730 2,380

12% 6,790 880 4,460

12% (44) 10,800 1,050 5,400

12% (44) 6,300 NA 4,700

Janka side hardness 390 lb for green material and 400 lb for dry. Amsler toughness 94 to 111 in.-lb for dry material (2-cm specimen).

Drying and Shrinkage: Dries rapidly with severe cup, sometimes with collapse, honeycomb, and checking. A kiln schedule similar to T6-B3 has been suggested. Shrinkage green to ovendry: radial 4.9%; tangential 8.1%. Movement in service is rated as small.

Working Properties: Usually saws easily and works well with hand and machine tools but cutters must be kept sharp; glues and finishes well; easy to rotary peel veneers.

Durability: Heartwood perishable, not resistant to termite attack; sapwood vulnerable to powder-post beetle attack. Rapid extraction and conversion necessary to prevent deterioration from stain, decay, and insect attack.

Preservation: Heartwood moderately to extremely resistant to preservative treatment sapwood permeable.

Uses: Plywood core stock, blockboard, boxes and crates, furniture components.

Additional Reading: (3), (4), (44), (58)