WAWABIMA
BOTANICAL NAME: Sterculia rhinopetala of the family Sterculiaceae

COMMON NAMES: awasea, awraw, aye (nigeria), brown sterculia, ekko okpon, enwiwan, false chestnut, kitiboa ufue, lotofa (ivory coast), m'kanang, mfotomfro, n'cannang, n'kanang, nkanna, nkannang, ogiokoko, oro, orodo, otutu, pokodom, potorodom, wawabima (ghana),

TYPE: hardwood

COLOR: The heartwood is pale to deep reddish brown and is sharply demarcated from the 1.5 to 2.5 inch wide straw-colored sapwood.

GRAIN / TEXTURE / FILLER / FINISH / LUSTER: Grain is typically interlocked, but may be straight. Plain sawn surfaces tend to be figureless, but numerous dark-colored high rays produce an attractive figure on quarter sawn surfaces. This is a very coarse wood and very fibrous. Most reports say general polishing and finishing qualities are rated as good, but some grain filling is required for best results. My own experience is that it is coarse and unpleasant to work and while I do agree that the quartersawn surfaces can be quite attractive, I find it not worth the effort.

PROPERTIES / WORKABILITY: This is a heavy and strong timber with very high toughness strength, which makes it suitable for construction applications where natural resistance to decay is not critical. It is hard and dense and very coarse and will fuzz up under most machining operations, which are difficult in any case because of the dense fibrous nature of hte wood. Splits easily, and that combined with the toughness means preboring is needed for nailing and screwing. The coarseness and toughness make it hard to work with hand tools but it machines reasonably well except for the tendance to fuzz up. Most reports say it has a tendance to spring when sawed, but at present I do not know what that means. Most reports say it has moderate dulling effect on cutters but my own experience is that it is VERY hard on router bits and turning gouges and I definitely do NOT recommend trying to turn it. Carving is reportedly only moderately difficult. Glues well. May exhibit gum and mineral deposits. The timber is reported to be peeled for plywood manufacture, corestock and facings for blockboards. It is also sliced into highly decorative veneers for panelling and interior decoration.

Pre-boring is recommended in nailing because it tends to split. For planing, a Slight tearing due to interlocked grain can be prevented by reducing cutting angles to 20 degrees and using sharp cutting edges. Material containing interlocked grain may cause worked surfaces to be rather fuzzy in moulding. Cutting edges should be kept sharp. Boring, turning, mortising, and other machining operations are reported to be generally satisfactory especially if sharp cutting edges are maintained, but surfaces tend to be woolly and it's tough on cutting surfaces.

The timber is reported to be peeled for plywood manufacture, corestock and facings for blockboards. It is also sliced into highly decorative veneers for panelling and interior decoration.

DURABILITY: The heartwood of is reported to have moderate resistance to attack by decay fungi and termites, but the sapwood is readily attacked by powder-post beetles and is prone to blue stain. The heartwood is reported to be impermeable and responds very poorly to preservative treatment. The sapwood is moderately difficult to treat.

STABILITY: Movement in service is large and the ratio of tangential to radial shrinkage is about 2 (not a good thing).

BENDING: knot-free material is reported to bend to a moderate radius.

ODOR / TASTE: has a slightly bitter taste but no distinct odor.

SOURCES: This West African species is found in the drier areas of lowland rain forests and savanna forests of Ghana, Ivory Coast, Nigeria, Benin, Cameroon, and Togo

USES: blockboard, boat building, boxes and crates, cabinetmaking, construction, flooring., flooring: industrial heavy traffic, furniture, furniture components, heavy construction, joinery, light construction, marine construction, paneling, plywood, posts, pulp/paper products, shingles, tool handles, toys, turnery, veneer: decorative,

TREE: The tree is reported to attain a height of 90 to 120 feet, with a trunk diameter of 2 to 4 feet. It produces straight, cylindrical boles that are about 70 feet long above well-formed narrow buttresses that rise to about 10 feet.

WEIGHT: 46 to 52lbs/ft3

DRYING: Drying is reported to be rather slow, and degrade can be severe if conditions are not carefully controlled. It is reported to be highly prone to cupping, and may develop other forms of distortion, but to a lesser extent. Considerable checking, end-splitting, opening of existing shakes, and slight collapse may also occur.

Shrinkage: Radial 5.0%, Tangential 9.5%

AVAILABILITY: low

COST: moderate

TOXICITY: no reports