Two-toned zebrawood offers arresting pattern.
Zebrawood emanates from West Africa, most coming from Gabon and the Cameroon Republic. It is a hard, heavy, dense and stable wood, but the mix of materials keeps it from being a good candidate for uses where strength is needed. The essence of zebrawood--the interplay between the very dark and very light colors--is the "culprit" because zebrawood's grain is a mixture of hard and soft materials. The mix makes it a hard wood with which to work. Still, woodworkers and artists have found a way around the limitations of this striking wood that is reminiscent of the coloring of one of nature's oddballs, the zebra.
Zebrawood is a popular choice for flush doors and for turnery and carving. The sliced veneer also finds its way into small cabinetry and high-end architectural uses such as inlay banding, marquetry and paneling, where strength and mechanical properties are of minimal importance. Fancy uses suit 'this wood, assuming one likes a strong, definitive grain pattern, for with zebrawood, a little goes a long way.
Most zebrawood, according to experts, is quarter sawn to avoid any buckling problems that result from the wood's hard and soft grain mix.
A stripe by any other name
The name "zebrawood" is also adopted around the world by other species. Most experts say the "rightful owner" of the term zebrano and zebrawood goes to wood from Microberlinia brazzavillensis and also from Microberlinia bisulcata of the Family Leguminosae. However, in some countries zebrawood is the adopted and common name for goncalo alves, which also features light and dark markings. In the United States, goncalo alves or Astronium fraxinifolium, is commonly called kingwood and tigerwood instead of zebrawood.
Larry Frye, executive director of the Fine Hardwoods/American Walnut Association, has been researching zebrawood and the various woods that go by the trade names zebrano, all originating from African forests. Frye said that according to his sources. "several trees yield a wood that looks alike and is sold as 'zebrawood.' This is a common practice with tropical species, that started over 100 years ago. The trees are Brachystegia leonensis, Brachystegia eurycoma, Brachystegia nigerica, Brachystegia boehmii and Microberlinia brazzavillensis."
Frye said that in Africa, the trees often had different common names in the different provinces: oakume and achit in Nigeria; meblo in the Ivory Coast; Zebrano in Gabon; Amouk in the Cameroons; and mjombo, mtondo, msasa, mafash, muputu, miombo, mienzi, molo, mtundo, mundu, and lohumbo in Tanganyika and Rhodesia. Frye added that the trees cut from both Brachystecia and Microberlinia are very similar and are both sold under the trade name zebrano, which leads some to speculate that the trees are really the same.
The wood with the golden heart
Zebrawood is a naturally lustrous wood. Its heartwood is a golden hue with stripes and streaks of dark brown that border on black. The wood is popular for accenting furniture, and is used as banding to provide contrast. Zebrawood is a dramatic looking wood. Its pattern varies and the grain is often wavy or interlocked. The sapwood can be as thick as 4 inches wide and is distinct from the heartwood. It is a tall tree, averaging 150 feet, and grows in what the U.S. Department of Agriculture's Forest Service calls "gregarious, pure stands along riverbanks" in West Africa. The trees have straight cylindrical boles that are "relatively short, up to 50 feet, with trunk diameters of 4 to 5 feet over low buttresses." When freshly cut, the wood emits an unpleasant odor, which diminishes after drying.
The very nature of its beauty, the dual grain/hard-soft mix, makes sanding difficult. In most other operations, however, the wood can be worked fairly well with machines or hand tools. The wood saws easily, but a clean and smooth finish is hampered by the interlocked grain which easily tears--a belt sander is recommended to get the best results. Often, the wood must be filled before finishing, Gluing poses problems, and special care is needed to get a proper bond.
Zebrawood is difficult to dry. Problems include warping, surface checking, splitting and distortion. The U.S Forest Service recommends a kiln schedule of T2-C2 for 4/4 stock and T2-C1 for 8/4 stock.
Zebrawood is a delicate wood to handle in the veneer stage as well. The best way to slice it is to quarter cut, but sliced veneer kept in stock may buckle. Experts recommend weighing down bundles to avoid buckling. When the wood is flat sawn or rotary cut, the zebra stripes are replaced with a very exotic pattern of streaks and stripes. The dramatic nature of the wood makes it a good choice for sculpture and also for specialty items like wood handles and small one-of-a-kind turned pieces.
Opinions vary on the durability of zebrawood. The U.S.D.A. Forest Service book, "Tropical Timbers of the World," calls zebrawood's heartwood durable. In other journals, however, it is rated non-durable. The heartwood is resistant to preservative treatment but the sapwood is permeable.
Zebrawood, Microberlinia brazzavillensis, also Microberlinia bisulcata, of the Family Leguminosae.
Zebrawood, zebrano, zingana, allene, ele, amouk, Allen ele.
Tree's average height is 150 feet. Average weight is 46 pounds per cubic feet. Specific gravity is 0.74.
Hard, heavy, stable wood unsuitable for steam bending. Rated brittle. Wood is difficult to dry. Has interlocked, wavy grain. Wood works well with hand and machine tools, except for sanding. Mixed grain poses finishing problems, too.
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|Title Annotation:||Wood of the Month|
|Publication:||Wood & Wood Products|
|Date:||Jul 1, 1994|
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