Woods To Know: Briar

Woods To Know: Briar

Briar (Erica arborea)

by Peter MacSween

Briar is a small tree, rarely growing more than thirty feet tall in its natural range, the coastal areas of the Mediterranean Sea. It is not harvested for lumber but for the burls, which grow between the roots and stem of this shrub. Burls have long been prized for their distinctive grain and appearance. Briar burls have a unique purpose: they are the preferred material for the bowls of tobacco pipes.
 
The discovery of this singular purpose for briar was accidental. A Frenchman traveling in the south of France to Corsica broke his pipe on route. He asked a local carver to fashion a new pipe out of whatever local wood was available. The craftsman chose Briar burl and the long history of Briar pipe making began.

wtk_briar
Briar burl block (plateaux)
 
Briar burl has several distinct properties that make it an ideal choice for pipe making. First, it is very hard and dense which makes it heat resistant. It can handle temperatures over 700 degrees Celsius before it will start to burn. This heat resistance is aided by extractives in the burl itself – which means that only tobacco burns in the bowl of the pipe and the briar does not add any flavouring.
 
In addition, Briar helps cool the smoke making it easier to inhale and ‘taste’ the tobacco. Being derived from the roots of the shrub, which are adapted to absorb water, the Briar burl takes up any hot moisture produced by tobacco combustion and in the process cools the smoke before it's inhaled. Finally, briar burls with their unique grain and appearance make a pipe that is very beautiful to look at. 
 
Burls are benign tumours or wart-like growths found in many different tree species typically on the stem or on the roots. The grain of the burl is an interlocked swirl. All burls have ‘eyes’ with the most prized burls having the highest density of eyes. The eyes are actually buds, the same buds one finds on the small branches and twigs that produce new growth.  No one knows why these eyes form in burls – distant from their normal location and purpose.  Many theories have been proposed such as trauma, insects, disease, etc., but we just don’t know what causes the burls to occur.
 
After the Briar burls are harvested, they are cleaned and cut into pieces suitable for pipe making. There are various types of cuttings available. Ebauchon blocks are usually rectangular in shape and cut from the center of the burl. These cuts maximize yield and are more widely available. Plateau blocks are wedge shaped and often include some of the bark of the burl. These pieces maximize appearance and figure and are more expensive. Blocks are often steamed which reduces drying stresses and helps even out colouration. Then the blocks are graded according to appearance and allowed to dry.
 
Even if you don’t want to make a pipe, Briar burls are affordable and offer the woodworker an introduction to working with burls. Briar can be used for small decorative objects and items such as knife handles. The burls should be cleaned thoroughly since they are dirty and can contain sand. Some woodworkers progressively remove wood in stages, letting the wood rest in between each step. This may help the wood dry and prevent cracking. It’s important to remember that burls are never kiln dried.  The interlocked grain would self-destruct. Success in working burls requires patience.
 
All tooling should be sharp since the wood is very hard and the interlocked grain can tear and chip. Waste will be high. Usually only one quarter of the burl will produce useable material. There are often bark inclusions and other defects to work around. Experience helps guide the hand when working the burl as the most dramatic appearance comes from viewing the eyes head on and not from the side. Finishing should complement the beauty of the wood not hide it. 
 
Briar burls are not endangered and are relatively easy to purchase. Dealers who supply pipe makers will stock the plateau and ebauchon blocks. Specialty wood dealers often stock whole burls, which are sold by the pound. Briar is an excellent choice for woodworkers willing to explore the gems of the forest and will reward the patient and persistent crafts person.
 
 
Average Dried Weight30 lbs/ft³A measure of its weight at 12% moisture and an ambient temperature of 70°F.
Specific Gravity.91A measure of the ratio of its density compared to water (at 12% MC)
ShrinkageRadial: 6.1
Tangential: 8.5
Volumetric: 15.6
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 Hardness2,090 lbfA measure of resistance to denting and abrasion.
Crushing Strength8,540 lbf/in²A measure of compression strength parallel to the grain.
Colour
Light tan and beige, to light brown and reddish brown. 
GrainTight grained, typically interlocked swirl or flame pattern (wood fibers grow radiating from a central point to the outer bark).
TextureRough, gritty.
Workability
Abrasive on cutting tools. Better suited for rasps, grinding tools, and sanders.
Uses
Tobacco pipes, knife handles, and other small specialty wood items.
Price$6.00 - $10.00 per pound

 
  
Photos and Specifications Courtesy of: The Wood Database