Wood of the Month:

Lustrous, Fragrant Guarea Found Throughout Tropical West Africa

By Jo-Ann Kaiser

FAMILY NAME

Guarea cedrata and Guarea thompsonii of the Family Meliaceae

COMMON NAMES

Guarea, white guarea, bosee, bosse, kwabohoro, obobo, edoucie, scented guarea, black guarea, obobonekwi, bosse, diambi, ebandhemwa, divuiti, piqua, African cedar, cedar mahogany, cedron, obobone, kwi

HEIGHT/WEIGHT

Both species grow to an average height of 160 feet with diameters of 3 to 4 feet. Guarea cedrata?s average weight is 36 pounds per cubic foot; Guarea thompsonii averages 39 pounds per cubic foot.

PROPERTIES

Works well with hand or machine tools; however, both species can contain gum, which will dull cutting surfaces. Interlocked grain can pose problems, too. Glues and sands easily, and holds nails and screws well. Material can be stained or finished well although gum deposits can pose finishing problems. Heartwood ratings vary from durable to moderately durable and moderately resistant to termite attack.

Two tropical West African species with a wide range of uses share the trade name guarea. The species Guarea cedrata is found in the Cameroons while the species Guarea thompsonii grows in Liberia but the growing range for both includes the Ivory Coast, Ghana and Nigeria.

Guarea is similar to mahogany in some respects, which has earned it the trade name cedar mahogany, although guarea is not a true mahogany.

Albert Constantine Jr., writing in the book Know Your Woods, explains the significance of guarea, which he refers to by the trade name bosse. "The wood has a pleasing pink to light mahogany color, has a fine grain and comes in stripes and mottles. The amount of sapwood is small and whitish in color; the heartwood is pinkish brown, darkening upon exposure, but not to the same extent as true mahoganies. The main characteristic of this tree is that it is generally superior to the American mahogany. The grain is either straight or wavy and the mottle figure is fairly common, but the stripe is far less frequent than that found in sapele."

Constantine adds that logs from the species are a good size for widths and lengths. "The wood is stiff, tough and strong, comparing favorably with Honduras mahogany, but being considerably harder."

Wood from the two species is often fine-grained and patterned with a stripe or mottle. The trade names African cedar, cedar mahogany and scented guarea are probably due to the fact that the wood emits a strong, pleasant cedar scent when cut. What is not so pleasant is the wood dust from working guarea, which can be extremely irritating to some and can cause skin irritation and breathing difficulties.

Differences and Similarities

The two species share many similarities, but there are some minor differences between the two. Guarea thompsonii is thought by some to have a deeper mahogany-like hue after it darkens. Guarea thompsonii is also heavier, averaging 39 pounds per cubic foot to Guarea cedrata?s 36 pounds per cubic foot.

According to the book, Encyclopedia of Wood, Guarea cedrata may exude resin, which can mar its appearance. Guarea thompsonii has less resin but tends to split, requiring greater care in drying. Guarea cedrata may contain silica while Guarea thompsonii is silica-free.

The two wood species work fairly easily with hand or machine tools, but can be wooly. Both glue well but finishing material with resin requires extra care. Gum spots, if present, can have a dulling effect on cutting surfaces but can be successfully sanded off. Both species steam bend fairly well, although Guarea cedrata is said to steam bend better of the two.

The long list of uses for this naturally lustrous wood includes furniture, cabinetmaking, drawer components, sporting goods, boat building, vehicle construction, high-end joinery, turnery, flooring, exterior plywood, and decorative veneers. The durable timber is sometimes used for marine pilings and is also used to make paneling, dowels, and rifle butts.

Seasoning Tips

According to the the U.S. Forest Service, Forest Products Laboratory, guarea dries fairly rapidly with little tendency to warp but may require some care to prevent checking. They recommend a kiln schedule of T6-D2 for 4/4 stock and T3-D1 for 8/4 stock.

Availability and Restrictions

OT Africa Line?s Commodity News regarding timber reports on its Web site that guarea is "reported to be secure with very little threat to its environment? in most areas of its range, but it is classified as endangered in Liberia and vulnerable in the Ivory Coast.

                                                                                                                                                                                           

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