Update on Cocobolo

Geographical Distribution

As I have written about Cocobolo before, consider this to simply be an update based on more recent working experience.  Cocobolo, scientifically known as Dalbergia retusa, is a tropical hardwood of the true Rosewood genus, Dalbergia, which grows in Central America.  Dalbergia retusa, a fair-sized tree, is reported to reach 15–25 meters in height and this is probably the species contributing most of the wood to the trade. Because of the wood’s beauty and high value, the trees yielding this wood have been heavily exploited and they are rare outside of national parks, reserves and plantations.

General Characteristics

Most often the yellowish sapwood of the Cocobolo, which is distinctly demarcated from the orange to reddish-brown, or even purple heartwood, is discarded and only the highly colored and figured Cocobolo heartwood retains commercial value and utility.  The heartwood is well known to change color after being cut and worked, which can lend to the appeal, but which can also pose problems if the original coloration and figure is highly desirable.  Fortunately, there are some well-known and relatively simple means by which color change in exotic lumber can be prevented or slowed.

It is important to note that Cocobolo is highly oily in both look and feel. The oil lends a strong, unmistakable floral odor even to well-seasoned wood and the oil can occasionally stain the hands with prolonged exposure.  However, the high natural oil content of the wood makes it difficult to achieve a strong glue joint, and can inhibit the curing of some varnishes, particularly oil based finishes.  A pre-wash prior to gluing of a solvent such as lacquer thinner or acetone, which are highly volatile and dry quickly after use, can make gluing easier, or even possible.  The high oil content also means that the wood stands up to repeated handling or to water and sweat under common usage conditions such as in gun grips and knife handles.

Some users report that the wood has a distinct scent when being turned although I have only experienced this to be mild if present at all.  However, it has been used in at least one women’s perfume so it must be pleasant to some.

Working Characteristics

The wood is quite hard and dense.  It is very finely textured as well, but with the addition of the high oil content it cuts and machines nicely and makes an almost ideal turning wood which can be cut so smooth, provided some skill and sharp tools, that finish cuts need little to no sanding, which is fortunate since Cocobolo is a nightmare to sand since the high oil content simply immediately loads most any abrasive pad or paper rendering it useless or risking burning the wood.  Abranet has proven successful in sanding Cocobolo if the screen is blown or rinsed out frequently.  Cutting with fine toothedblades may also cause loading, so care should be taken to examine the blade frequently.  The high oil content of Cocobolo also means that it can be easily polished to a high gloss finish even with the addition of other finishing chemicals or waxes.  Due to its density and hardness, even a large block of the cut wood will produce a clear musical tone if struck. Cocobolo can be polished to a lustrous, glassy finish.

Pricing

Only relatively small amounts of prized Cocobolo wood reach the world market and therefore it is expensive.   Pen blanks can be purchased for $1.50 to $3.00 each, while a more substantial bowl blank size measuring 8”x8”x3” retails for slightly under $60 at an exotic wood retailer such as West Penn Hardwoods, a reliable source for bowl blanks from many species at fair prices.  Other exotic wood suppliers may also have Cocobolo in stock as it is a relatively common exotic wood in dealers stock.  Woodfinder is a website that is dedicated to advertising exotic wood dealers and I can’t speak to the quality of any of them, but they do have the advantage of performing searches based on your location which might allow you to visit a wood dealer in person to hand pick what you want to work with at a price you are comfortable paying.

Uses

Besides its use in gun grips and knife handles, cocobolo is favored for fine inlay work for custom high-end cue sticks, police batons, pens, brush backs, and musical instruments, especially guitars, drums and basses. Cocobolo is famous as a “tonewood,” or a wood used to make musical instruments, and even large blocks of Cocobolo will emit musical tones when struck.  This may be again due to the high oil content of the wood.  There is abundant other information available for those who are interested in detailed musical applications including manufacturers and players who have used Cocobolo instruments that is beyond the scope of this post, but which you can read about on-line.  More uses include decorative and figured veneers, bowls, jewelry boxes, luxury pens, duck and goose calls, and other expensive specialty items. Some cocobolo has a specific gravity of over 1.0, and will sink in water which can allow its use in very specialty items like fishing lures and weights.

Health Hazards Associated with Cocobolo

As with all true rosewoods, care must be used when cutting Cocobolo, as the wood’s oils can induce allergic reactions if inhaled or exposed to the unprotected skin and eyes of sensitized people. Complete information about health hazards associated with a wide variety of exotic hardwoods is available from The Wood Database along with additional information about the best use of a dust collection system, coupled with the use of personal protective equipment such as respirators, which is highly recommended when machining this wood.  Fortunately, I have never experienced any negative side effects from working with Cocobolo.

My Personal Experiences

I have long found Cocobolo to be a joy to work with.  I appreciate its tight grain and low porosity because with the careful use of a sharp fresh carbide blade I can achieve a cut that doesn’t require sanding either at all, or at a grit as low as 400 or 600 more to polish then to cut.  The color palate will vary from piece to piece but I love the creams and violets that I commonly encounter in some pieces as well as the more common dark reds and browns in swirls and high figure.  The wood is extremely easy to finish since it really only needs a high buffing to achieve a high gloss from its natural oil.  The preservation treatments don’t obscure the beauty but they can help preserve what you see on the fresh cut wood if you don’t want to risk the darkening that will likely happen over time.  I have not personally experienced difficulty gluing with cyanoacrylate glues but other types might require a pre-wash with acetone or lacquer thinner to dissolve the surface layers of oil prior to glue application.  I look forward to working with Cocobolo on even larger scales in the future including the making of relatively large bowls from blanks that are currently slowing seasoning in the wood pile.