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Wood of the Month:
Goncalo Alves -
Beautiful and Durable

By Jo-Ann Kaiser


FAMILY NAMES
Astronium fraxinifolium of the family Anacardiaceae. Also from Astronium graveolens.

OTHER NAMES
For Astronium fraxinifolium: Goncalo alves, zebrawood, tigerwood, kingwood, bosona, urunday-para, mura, and bois de zebre. Other names for Astronium graveolens: chibatao, guarita, urunday and aderno.

HEIGHT/WEIGHT
Average height is 120 feet with diameters of 2 to 3 feet. Average weight is 59 to 63 pounds per cubic foot with a specific density of 0.95.

PROPERTIES
Timber is difficult to dry with a tendency to warp and check. Experts recommend slow air drying. Shrinkage on drying is rated low. Wood has small movement in service. Texture is medium and uniform. Wood's density and interlocked grain can make it difficult to work and cause moderate to severe blunting of cutting tools. Cutting edges should be kept sharp. Wood is made of contrasting hard and soft material plus irregular or interlocked grain. Experts recommend a reduced cutting angle of 15 degrees. Preboring recommended for nails and screws. Wood finishes well. Wood is highly durable, unaffected by moisture, insect and fungal attack, and extremely resistant to preservatives. Not suitable for steam bending. Material turns and carves well.

Goncalo alves is sometimes referred to as zebrawood or tigerwood - names that underscore the wood's often dramatic, contrasting color scheme. While the sapwood is very light, the heartwood is a mix of deep red and brown, often with dark streaks and colorations that give it a unique look that some compare to rosewood. The wood's color deepens with exposure and age and even the plainer-looking wood has a natural luster.

Goncalo alves grows plentifully in the forests of Mexico, Central America and in South American countries including Ecuador, Colombia, Venezuela and Brazil. Brazil is a major exporter of the wood.

Two species are usually listed as sources for goncalo alves. They are Astronium fraxinifolium and Astronium graveolens. The wood from the latter is usually more straight-grained, less dense, and slightly plainer in looks than the former.

Variety of Uses
In addition to its strength and density - its weight averages between 59 and 63 pounds per cubic foot - the wood is extremely durable, weathers well and is highly resistant to moisture. These properties lend it to utilitarian uses in the countries where goncalo alves grows. Heavy-duty applications include general construction, flooring and exterior joinery.

Jim Dumas, president of Certainly Wood in East Aurora, NY, describes goncalo alves as extremely heavy. "Of the 300 or so commercial woods sold, it is one of the heaviest," he says.

According to "Wood Handbook - Wood as an Engineering Material," published by the USDA, "The high density of the wood is accompanied by equally high strength values, which are considerably higher in most respects than those of any well-known United States species." However, the wood is not imported for its strength. In the U.S. market, goncalo alves is usually prized for its beauty.

Goncalo alves is used to make the dampers in grand pianos, but the tree is also a source of beautiful lumber and veneer used in furniture, cabinetry, marquetry and specialty items such as billiard cue butts, archery bows, and jewelry boxes. It is also popular for turnery and carving. Veneers are used for architectural applications such as paneling. The distinctive-looking wood is often used with other woods as an accent.

Working With the Wood
Dumas says the wood is very oily, which causes problems with gluing.

"We sell it with a disclaimer and tell people who plan to glue the veneers that other customers have reported problems," Dumas says. "I think if it weren't for the difficulties in gluing, it would be a much more popular wood because it is very dramatic. It is a cross between ebony and teak with broad black lines. Some novices mistake it for marble wood because it has that look."

Dumas says his company keeps goncalo alves in pallet form for customers who use it for specialty items such as gun handles and custom fishing rod grips. "One manufacturer makes custom grips from the solid goncalo alves by having customers imprint their grip in a material like Play-Doh, which is used as the pattern for the wood grip," he adds.

Another of Certainly Wood's customers, a New York fashion designer, used highly figured goncalo alves veneer for paneling in a showroom. "The wood has a natural luster. The right piece can be very dramatic. Non-figured goncalo alves is very bland. People usually buy it for the distinctive figure," says Dumas.

Goncalo alves can be difficult to dry. The USDA's Forest Products Lab recommends a kiln schedule of T3-C2. Problems in seasoning the wood include "some crook and bow accompanied by a slight tendency to twist."

All in the Family
Goncalo alves belongs to the Sumac and Cashew (Anacardiaceae) family, which includes some 600 species around the world. Relatives of the tree include the tropical cashew, pepper trees, mangoes and pistachio trees. Cotinus obovatus, or the smoke tree, grows in the United States and is also from the same family. Smoke trees, which are grown as ornamentals, are especially beautiful in autumn when their leaves turn.

                                                                                                                                                                                           

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