Cocobolo or cocobola (Dalbergia retusa) is one of the most beautiful appearing woods in the world. (Sometimes cocobolo is called Nicaragua rosewood. In Mexico, the wood is called granadillo.) The Dalbergia genus also includes Brazilian rosewood and Honduras rosewood, but cocobolo is heavier and stronger and is often consider more beautiful in appearance.

The cocobolo tree, found growing in Central America, including Costa Rica, Nicaragua, Panama, Mexico, Colombia, Salvador, Honduras, and Guatemala, is rather short (60 feet at most) and usually less than 24 inches in diameter. It requires at least 80 years to reach maturity. Being a deciduous (meaning a tree with leaves) legume tree, it does have pods, but usually there is only one seed in a pod. Being a legume, it can fix nitrogen in the soil, so it is an important tree in tropical areas where heavy rains tend to leach nutrients from the soil.

The primary use of this wood is in the cutlery business. Cocobolo wood makes beautiful handles that have great color, natural water repellence, and high surface hardness. Another common use is for fine guitars; reportedly, the musical properties are fantastic. When the wood has a lot of grain figure, which is commonly found in veneers, it will be used as an accent wood for fine furniture.

The scarcity of this wood (slow growth; over-harvesting in the past; restricted harvesting in some countries--CITES Appendix III) and its wonderful beauty mean that prices are extremely high. We cannot afford to use it today for more than accent woods.

Of major concern is that contact with the wood, especially the dust, can produce a reaction similar to poison ivy in many people. Apparently, the dust mixes with perspiration to create this reaction on the skin. Breathing problems also occur.

Processing suggestions and characteristics

Density.

This wood has a density when kiln-dried over 1.0. In other words, it doesn’t float. It is 50 percent heavier than oak. When kiln-dried, this wood will weigh at least 70 pounds per cubic foot; a KD piece of lumber planed to 3/4" thickness will weigh over 4 pounds per BF.

Drying. Drying requires great care as the wood is prone to warping (especially when the grain is swirly or interlocked) and prone to face cracking or checking. Drying procedures, including kiln schedules, are the mildest possible. Nearly all wood found in the marketplace will be already air-dried. Checks may not be obvious at this moisture content, but may re-open when kiln dried or machined. Shrinkage in drying is reported to be under 4 percent, which is quite low.

Gluing and Machining. The wood is quite waxy and so gluing is extremely difficult, even if surfaces are cleaned with a solvent just before gluing.

Machining is moderately difficult, as with all dense woods and woods with interlocked grain, but the waxiness actually enhances final machining giving a wonderful smooth, polished surface. Note the previous comments about severe allergic reactions to this wood and its dust. A freshly machined piece of cocobolo has a spicy smell.

Stability. This wood is amazing stable, considering its density. Overall, it requires a 7% moisture content change for a 1 percent size change tangentially (across the width of flatsawn material) and 10% change for a 1 percent size change radially. This is roughly twice as stable as most U.S. hardwoods. In addition, the waxiness provides resistance to moisture absorption.

Strength. There is no published strength data, but it certainly is stronger and stiffer than its close relative Brazilian rosewood. The values for Brazilian rosewood are ultimate strength (MOR) = 19,000 psi; stiffness (MOE) = 1.88 million psi; and hardness = 2720 pounds. For comparison, northern red oak values are 14,300 psi, 1.82 million psi and 1290 pounds.

Color and Grain. The heartwood has quite a few different colors, but after exposure to light, the wood turns dark red with some black stripping at times. Apparently, the darkening continues for years. The wood has natural luster.

Some woods have rather straight grain, but others have very swirly grain patterns. Overall the surface grain is very smooth.

There are some reports that the color is partially dissolved by some finishes and then can bleed into adjacent, lighter colored species.

 

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