Woods to Know: Bubinga - Canadian Woodworking Magazine

Woods to Know: Bubinga

Bubinga (Guibourtia spp.)

Most woodworkers are familiar with the common and beautiful African heavyweight, Bubinga. Famous since the 1700's for its rich and distinctive colour and figure, it is now renowned for the large live edge tabletop slabs it produces. More than twenty species of Bubinga are found worldwide, with a dozen located in the West Equatorial region of Africa. Of these twelve, 2 species (Guibourtia tessmannii and Guibourtia desmeusi) are commonly exported as African Bubinga or under its other common name, African Rosewood. It typically grows alone or in small stands favouring moist habitats such as swamps, riverbanks and lakeshores.
 
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Bubinga, unfinished
 
The tree can reach heights over 160', clear of branches for the first 60'. Diameters of 6' or more are not uncommon. Logs from these trees can weigh over 10 tons, so they are floated out of the jungle during the rainy season. The sheer weight of the wood can also help explain its popularity as a veneer, and the sliced veneer is easier to ship to market due to its lower weight.
 
Bubinga found its way into Europe by the 1700s where it was quickly incorporated into French Renaissance furniture. It became known as 'bois de rose d'Afrique' or African Rosewood since it shares many superficial characteristics with the true rosewoods such as its colour and the presence of oils. However, it is not a botanical member of the rosewood family. 
 
The reddish purple heartwood often contains streaks that vary from dark red to black. The sap is a creamy white sharply demarcated from the heart. The grain varies from straight to interlocked and the texture is fine. Bubinga is heavy, dense, and exceptionally hard. This is a durable wood due to the presence of oils that protect it from insects and decay. All types of figure are commonly found: mottled, curly, quilted, pommele, and waterfall. The wood is often sliced into veneer to take advantage of these diverse figure types in cabinetry and architectural applications. It dries well and is considered stable.
 
Straight grained Bubinga machines well with sharp carbide tooling. Unless you want to break into a sweat, hand tools are not advised. Wood with interlocked grain and/or high figure will be difficult to work without chipping and tearing out. Slower feed rates and different cutting angles can be used to reduce tear out. Pre-drilling for screws is advised and waxing any screws will make installation easier. The oils and density can make gluing a challenge. Wiping the wood with acetone to remove the oils from the surface to be glued may help. Increased clamp pressure should be considered to avoid starved glue joints. The wood stains easily and can be finished to a wonderfully high polish. The pores do not have to be finished, although sealing the wood may be necessary to prevent the oils from bleeding through the stain or finish.

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Bubinga end-grain
 
Bubinga is commonly used for furniture, tabletops, and flooring. Since it turns well, it is also used for bowls, pens, and decorative articles. However, it does not carve well. Bubinga is often used in drums and acoustic guitars because of its excellent tonal qualities wood. Rotary cut veneer can yield a swirling, psychedelic figure called Kevazinga, often seen in architectural installations.
 
Supplies of Bubinga are constant and stable for now. Export constraints on Bubinga may limit its future availability as the exporting countries try to sell more added value products. Non-figured, dimensional Bubinga represnets good value considering its pedigree. Prices can be expensive for the highly figured wood and large tabletop slabs. Diverse in appearance, Bubinga can offer the woodworker a rich palette to choose from for a multitude of projects. 
 
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Krenov style handplane in Bubinga by Michael Kampen (view the article)


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Ode Desk in Bubinga, Satinwood, and Ebony, John Morel

 
Average Dried Weight56 lbs/ft3A measure of its weight at 12% moisture and an ambient temperature of 70°F.
Specific Gravity.89A measure of the ratio of its density compared to water (at 12% MC)
ShrinkageRadial: 6%,
Tangential: 8.2%,
Volumetric: 13.9%
Radial (the amount of crosswise shrinkage);
Tangential (the amount of lengthwise shrinkage);
Volumetric (the total amount of shrinkage.)
T/R Ratio1.4A measure of the uniformity of tangential to radial shrinkage.
Janka Hardness2,410 lbfA measure of resistance to denting and abrasion.
Crushing Strength10,990 lbf/in2A measure of compression strength parallel to the grain.
ColourHeart is deep red/purple with dark streaks. Sap is a creamy white. 
GrainStraight to interlocked. Diverse types of figure often present.
TextureFine
Workability
Can be difficult depending on figure present, tear out is possible. Carbide tools a must. Gluing can be difficult due to presence of oils. Turns and finishes well. Difficult to carve.
UsesFurniture, flooring, tabletops, veneer, turnings and decorative objects.
Price$12.05/BF (4/4 stock)
$13.25/BF (8/4 stock)
$2.85 (per sq. ft., figured veneer)
Approximate Pricing
Dependant on amount of figure present.

 
  
Photos and Specifications Courtesy of: The Wood Database