GONCALO ALVES

BOTANICAL NAME: Astronium spp., mostly A. fraxinifolium and A. graveolens both of the family Anacardiaceae, the cashew family. The wood from the latter is reportedly more straight-grained, less dense, and slightly plainer in looks than the former. Also A. lecointei (trade name aroeira)

COMMON NAMES: aderno, almedro macho, arathanha, aroeira do campo, aroeira preta, batao, bauwana, bois de zebre, bosona, bossona, bototo, chibatao, ciruelillo, ciruelo, coubaril, cubatau, diomate, frijolillo, gateado (venezuela), gomavel, guarabozebra, guarabu bata, guarabu encirado, guarabu rajado, guarita (brazil), guasango (ecuador), gusanero (colombia), gusango, jejuira, jenjuira, jobillo, kingwood (not to be confused with the real kingwood), locustwood, maracatiara, masicaran, muira, muiracatiara, muiraquatiara, mura, ormigo, palo de cera, palo de cruz, palo de culebra (mexico), palo obero, potrico, quebracha, quebracho, rajado branco, red astronium, robel gateado, ron ron, ronron, roron, sangue, tibigaro, tigerwood, ubatin, urunday, urunday-para, vermezho, yoke, yomato, zebrawood (not to be confused with the real zebrawood),

Goncalo alves is commonly called tigerwood which underscores the wood’s often dramatic, contrasting color scheme, but many planks are very plain and not particularly attractive. Although it is also reportedly called zebrawood, I have never seen it referred to as such, and there is another very distinctive wood named zebrawood which is nothing like this wood. The name kingwood is often listed as a common name for this wood, but I have never seen that in actual use and there is a different and very distinctive wood that is normally referred to as kingwood.

It 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.

TYPE: hardwood

COLOR: ranges in color from light to orangish/reddish brown to deep mahogany red-brown with a striking figure in some pieces created by beautiful, bold, brown to nearly black irregular markings or striping. The sapwood is very light. The heartwood exhibits a large degree of color change over long exposure, with a pronounced darkening of the background under the stripes from an orangey tan to a deep reddish brown color, which then in turn makes the striping less contrasting and more subtle. It sometimes happens, but not commonly, that some areas on a plank of this wood will bear a striking resemblance to macassar ebony, being a creamy tan with black streaking.

GRAIN: fine, varying from straight to interlocked and wavy.

TEXTURE: fine to medium and uniform. My experience is on the fine side, and many reports warn against coarse sandpaper because of the fine texture. One report recomments scraping rather than sanding, for that reason. Natural luster is moderate.

PROPERTIES / WORKABILITY: very stong and durable with strength values considerably higher than any well-known U.S. species. In spite of its high density, it turns readily, carves well. It can be finished very easily and polishes very well due to the fine texture. No grain filling is required, also due to the fine texture. The wood’s density and interlocked grain can make it difficult to work and cause moderate to severe blunting of cutting tools but straight-grained pieces are a pleasure to work with. Cutting edges should be kept sharp. Preboring recommended for nails and screws but holding of nails and screws is good. Several reports mention tearout/chipping as a potential problem especially when boring with twist drill bits. When ripping, a low-tooth-count blade is highly recommended. Sands very well, turns well (although interlocked-grain pieces can be a problem), and reportedly carves reasonably well, although reports on carving are mixed --- some say it's pretty difficult to carve.

At least one expert says the wood is very oily, which causes problems with gluing. Personally, I have found it to be just a tiny bit oily, but I have had absolutely no problem glueing it, perhaps because I only glue freshly rough-sanded pieces. See the web quote below on glueing veneer. Several reports do recommend pre-treatment to reduce oils before gluing.

Gum and resin pockets and streaks are occasionally reported as potential problems.

DURABILITY: highly durable, unaffected by moisture, insect and fungal attack, but extremely resistant to preservatives. Very durable mechanically and sometimes used for flooring because of that.

FINISH: Wood finishes well and takes a high natural polish because it is so dense. A clear finish will enhance the beauty of the wood.

STABILITY: small movement in service

BENDING: not suitable for steam bending

ODOR: no distinctive odor or taste

SOURCES: Central and Latin America; Brazil is a major exporter of the wood, but it also comes from Argentina, Bolivia, Colombia, Columbia, Costa rica, Ecuador, Guyana, Honduras, Mexico, Paraguay, Peru, Trinidad and tobago, Uruguay, and Venezuela.

USES: accent wood, archery bows, bedroom suites, billiard cue butts, boat building, bobbins, bows, bridge construction, brush backs, building construction, cabin construction, cabinetmaking, cabinetry, carving, chairs, chests, construction, dampers in grand pianos, decorative veneer, desks, dining-room furniture, exterior joinery. factory construction, figured veneer, fine furniture, flooring, fuelwood, furniture, handles, heavy construction, jewelry boxes, joinery, joinery (external with ground contact), knife handles, ladders, light construction, living-room suites, marquetry, mine timbers, musical instruments, paneling, piling, plywood, posts, railroad ties, shafts/handles, shutters, specialty items, sporting goods, tool handles, toys, turnery, vehicle parts, wardrobes, wheel spokes, wheels

TREE: a large canopy tree, sometimes with heights to 150 feet reported, although 120 is more normally reported as the maximum. Trunk diameters of 4.5 feet have been reported, but but 3 to 3.5 is the normally reported maximum. The tree has a clear, straight cylindrical bole for two-thirds or more of its height, above a buttress that can rise as much as 6 feet (usually less). The logs are typically sound throughout.

WEIGHT: reports range from 53 to 80 pounds per cubic foot which is quite a range, but the upper end is highly suspect, I believe. My own experience has been in the 60 lbs/ft3 range and most reports are in the low 60's.

DRYING: Can be difficult to dry --- slow air drying is recommended. Drying problems include warping (crooking and bowing), checking, and a slight tendency to twist. Rapid air-drying rates may cause excessive warping and checking.

AVAILABILITY: readily available

COST: readily available under $10/BF, but I assume that this is for the more plain planks. Figured pieces go for much higher prices, with highly figured pieces regularly commanding $20/BF, though you might get lucky and find terrific pieces for $12 to $15/BF. I've never gotten lucky.

I have found Gancalo Alves to be less interesting than the more figured pieces I've seen pictures of would suggest, but I assume that that's BECAUSE the pieces I've owned were not the more figured pieces. Most of the pieces I've owned were quite bland compared to what this wood is apparently capable of, although one of my samples is, as you can see from the pics, quite variagated in color.

web quotes:
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Goncalo alves has been heavily exploited because of its great beauty. It is now rare outside of the protection of national parks, and is listed as threatened in "Arboles Maderables en Peligro de Extinción en Costa Rica."

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.

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.
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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.

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.
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Goncalo alves is sometimes referred to as zebrawood or tigerwood which underscores the wood’s often dramatic, contrasting colors. While the clearly demarcated sapwood is light colored (generally a dirty grey or brownish-white), 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 develops a patina, particularly if left unfinished, due to the exudation of natural oils in the wood. Many planks are, in my experience, and based on wide examination of pictures on the Internet, merely a nice honey-brown with mottled black streaking, which is a far cry from the beauty that is sometimes found in the wood. Not a good wood to buy sight-unseen.