Woods to Know: Wenge - Canadian Woodworking Magazine

Woods to Know: Wenge

Wenge (Milletia laurentii)

by Peter MacSween

Wenge is one of the most popular of the imported exotic hardwoods. With most hardwoods being light in colour, Wenge is renowned for its rich dark brown heartwood. One could argue that its relatively rare and distinct figuring inspired its original use in Africa for ceremonial masks and religious carvings. 
 
Wenge is a modest tree, typically growing to 60 feet with a trunk diameter of 2 feet. Some specimens can reach 90 feet in height with diameters approaching 4 feet.  It is found in the swampy areas of Zaire, Cameroon and Gabon. A closely related species Panga-panga (Millettia stuhlmannii) resembles Wenge, but it is lighter in colour and comes from the drier interior African countries of Mozambique and Tanzania.

WTK_wenge
The heartwood of Wenge is dark brown with contrasting creamy white demarcated sapwood. The heart possesses fine black and white striping, which gives the heart a distinctive feathery appearance. When quarter sawn, Wenge displays instead a very linear and striped grain. The tree’s parenchyma cells that serve the tree by providing food storage and transport produce these black and white stripes.
 
Wenge’s grain is straight and coarse. It is very fibrous which can make machining difficult especially when creating edge profiles. The rough material is also notorious for producing small splinters, which can easily become infected. Gloves are a must when handling the rough board. Happily, this propensity for splintering disappears in the dressed material. 
 
Wenge is also a dense wood.  Wearing extremely well, it makes a fine floor. Tools should be carbide and kept sharp as the wood can blunt tools. Nails and screws should be predrilled. Resin producing cells are present which can make gluing a challenge, so material should be glued shortly after machining and clamping pressure should be watched carefully. Too much clamp pressure can produce starved glue joints. 
 
Wenge finishes well with few concerns. The light and dark areas can have different densities; so vigorous sanding can produce a rippled surface. The resinous nature of the wood can be problematic with some solvent-based stains. If a smooth surface is required, the large pores will have to be filled.  Application of oil-based finishes can turn the wood almost black, which can be a desirable effect.

WTK_wenge-endgrain
Wenge endgrain
 
Wenge has been used in all types of interior and exterior applications. Once dried, it is stable and suited for cabinet making as well as flooring. Its dark colouring is often used as a contrasting feature in segmented turnings and decorative accents. It carves well, and its unique appearance enhances many decorative objects. This wood has also found a home in luthiery, especially for solid body guitar frames, fingerboards and necks. It is also a very common decorative veneer, especially when sliced on the quarter. 
 
Woodworkers should be aware that the fine dust produced by Wenge can produce allergic skin and respiratory reactions. I would recommend a good dust mask and proper dust collection. 
 
Wenge is considered a threatened resource. This has been caused mainly by over exploitation and habitat destruction. Careful use and continued management will guarantee future access. Its dark colour means a little will go a long way, especially when used as a contrasting design element in inlays and bandings. For those who want build larger pieces with Wenge, I would recommend using veneer. The quarter sliced veneer is spectacular and using Wenge in this fashion will help preserve this distinctive species.
 
 
Average Dried Weight54 lbs/ft³A measure of its weight at 12% moisture and an ambient temperature of 70°F.
Specific Gravity.87A measure of the ratio of its density compared to water (at 12% MC)
ShrinkageRadial: 4.8
Tangential: 8.1
Volumetric: 12.9
Radial (the amount of crosswise shrinkage);
Tangential (the amount of lengthwise shrinkage);
Volumetric (the total amount of shrinkage.)
T/R Ratio1.7A measure of the uniformity of tangential to radial shrinkage.
Janka Hardness1,930 lbfA measure of resistance to denting and abrasion.
Crushing Strength 11,710 lbf/in²A measure of compression strength parallel to the grain.
ColourHeartwood is dark brown contrasting with creamy white demarcated sapwood.
GrainStraight.
TextureMedium to coarse.
Workability
Somewhat hard to work - make sure tools are sharp.
Uses
Fine furniture, cabinetry, musical instruments, veneer.
Price$19.20/bf  4/4 stock
$21.75/bf  8/4 stock
$3.25/ft²   Veneer
 
  
Photos and Specifications Courtesy of: The Wood Database