An overview of African hardwoods

AHOGANY is the most widely lUlrecognized hardwood from Africa, but many imported forest products suppliers include other African hardwoods on their species lists. Obeche, afrormosia, irokb, mansonia, limba, shedua, and zebrawood are important, frequently as teak and walnut substitutes.

African mahogany, KhaYa sPP., is produced by five species found throughout the continent, but commercial timber is mainly K.ivorensis and K.anthotheca shipped from West Africa. Related to Swietenia botanically, the African wood was first used at the end of the last century to supplement the limited supplies of true mahogany from Mexico. Central. South Africa. and southem Florida in the United States. Today it is almost universally accepted as mahogany.

Pale-pink to red-brown in color with a medium texture and interlocked grain with a stripe figure the wood is considered light in weight.

Rated as easy to dry and stable in use, African mahogany is recognized for good working and finishing properties. On the negative side, some timber from the center of large logs maY be brittle and care is needed with quartercut surfaces. It is considered moderately resistant to fungi.

Alttrough the demand for mahoganY furniture has declined, the wood is still used in antique reproductions and office furniture. The veneer is very decorative. Other uses include drawer sides, and in joinery for doors and commercial interiors. Light and moderately durable, it also is a popular choice for boat building. An additional use is for general-purpose plywood.

One of Africa's leading export timbers, obeche, Triplochiton scleroxylon, is commonly found in the Ivory Coast, Ghana, Nigeria and Cameroon areas. The tree grows very large with a long straight tnrnk.

iomi'aratively, ii is oie of the lightest hardwoods in use, generally weighing about the same as the liehtest softwoods, or twice the wEieht of balsa. It is considered very attrlctive with a pale straw-yellow color that has a silky sheen as a result of natural high luster. Decorative- ness is enhanced by a Pronounced stripe in the quartered sections from the combination of medium texture and interlocked grain.

The wood can be dried raPidlY with very little degradation. It is very stable in use although not strong because of the light weight. Its workability rates well although care must be taken in cutting end grain surfaces as they tend to cmmble. Cutters must be kept sharP to Produce a eood finish. The veneer is considered Excellent.

Story at a Glance

Af rican hardwoods. . good workability. decorative figures. . used in furniture, Yeneer, boat building... look alikes for mahogany, teak, walnut.

The wood is perishable and raPidlY attacked by fungi in conditions favorins decay.

-necau-se it is attractive and easy to work, obeche is desirable for uses where mechanical strength is not important. Cabinetwork framing, drawer iides, mouldings, interior joinery' and plywood are common uses.

Afrormosia, PericoPsis elata, is also known as kokrodua. It is native to the Ivorv Coast, Ghana, Cameroon, the Congo-, and Zaire, with the principal loeging done in the lvory Coast anlO Ctrin-a ieas. The tree is tall with a lons and often irregular trunk.

It is a substitute for teak although it does not have the leatherY smell and sreasiness to touch. Like teak, it is iellow-brown to brown in about the slrne weight with a finer texture. The interlocked grain Produces a striped figure. In moist conditions it is^ know-n to react with iron fixings and blacken in color.

It dries slowly with little degradation and is very stable when dried. A strong wood, it is rated better than teak in most strength properties. Durable and resistant to both fungi and termites. it saws and works well taking a fine finish. Quarter-sawn surfaies require careful handling because of the interlocked grain.

"Getting hard to get hold of," according to an industrY executive, afrorm6sia has been marketed onlY since World War II. First used as a teak substitute, it is now accePted on its own merit for furniture both in the solid and veneer. Its most imDortant use in the United States is in the boat building industry'

Another teak substitute, iroko, Chlorophora Excelsa and Regia, is known-as kambala when it comes from the Congo. Coarser textured, a little liehter in weight and less strong than teik. it also laiks the distinct odor and feel.

Yellow-brown to deeP brown in color, it has light markings caused by the vessels. The texture is coarse and uniform with an interlocked grain' Weieht is about 40 lbs. per cubic foot.

Tte wood saws and rirachines well. However, stony deposits of calcium carbonate can damage saw teeth and cutters.

Although iroko is not as enduring as teak, it is cheaper, according to an industry spokesman, which makes it suitable fol manv purposes even if it is not particulaily d'ecorative' Not utilized to any great extent in this country, it is suitable for boat building, jdinery, counter and bench toPs, and parquet flooring.

Mansonia, Mansonia altissima, is not readily available here. Produced in West Africa from a tree of modest size, it is a good walnut substitute. Medium brown to dark brown, the wood often has a greY or PurPle tint and is sometimes faintly striped. With exposure it can lose.the dark color and eventually fade to a pale yellowish brown. Fine textured with a straight or interlocked grain, it falls between mahogany and walnut in weight.

Thi w'ood dries quickly wittr tittte degradation although it has a tendency to-split. After drying it is moderately stable. It is a strong wood comparable to beech except for stiffness. Durable, it is resistant to fungi and termites.

Alttrough it saws well and machines to a good finish, the wood dust irritates the skin, eyes. nose and throat. Because of this, it is not in wide commercial use. Suitable applications would be highclass joinery, furniture, cabinets, and fittings.

Limba, Terminalia superba, is known in most English speaking countries as afara and in the United States as korina, the copyrighted name for selected limba plywood-. Alttrough the tree is found'throushout We"st Africa, most commerc-ial timber comes from Zaire and western central Africa.

Limba varies in color from pale straw to darker with irregular gray markings. Medium textured with a straight or slightly interlocked grain, it usually weighs about the same as mahogany. It dries rapidly and well. Stable, it has moderate strength although this can vary with density and some timber is brittle.

Light limba is a popular general purpose wood in Europe with the darker colors used for veneer. In the United States it is used primarily for decorative plywood. A hardwood importer classifies it as nice, but hard to obtain.

Zebrawood, also known as zebrano, comes from two large trees, Microberlinia brazzavillensis and M. bisulcata, in Cameroon and Gabon. Usually the pale sapwood is adzed off and bnlv the fisurid heartwood is exported.'

Straw colored or pale brown with many dark brown or almost black stripes, the wood varies in appearance from log to log. The method of conversion also changes the appearance. On quartered surfaces. it mav have a rejular and parallel stripi while on flat or rotary cut surface the pattern is less resuiar. With interlocked grain and Eoarse texture, the wood is moderatelv dense and weighs slightly heavier-than oak.

Zebrawood must be dried with care to prevent twisting. Distortion can be kept to the minimum in the solid by quarter sawing. With good strength properties and shock resistance, it works well by hand or machine to a good finish. The wood slices and peels well for veneer although the product tends to be somewhat fraeile. It appears to be fungi resistant.

A very distinctive and decorative wood, it is mainly used as slice veneer in decorative inlav for cabinetrv and furniture. Solid w'ood can be ui"A in brush back, handles, and small turned items which are attractive. Its shock resistant qualities suggest possible use in tool handles and skis.

Shedua is offered bv a limited number of imported woodhealen although there is little technical information available. It is used primarily as a walnut substitute.

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