Woods to Know: English Oak

Woods to Know: English Oak

English Oak (Quercus robur)

English Oak has a rich and illustrious history throughout Great Britain and Europe. Famed as a shipbuilding timber, it helped power the rise of the English Navy. It is also the most common tree in English forests and is revered there as a symbol of British durability and strength as a nation. 
 
English or European Oak grows throughout Europe, south to the Mediterranean and east to Asia Minor. Some authorities consider the Eastern and Southern varieties as a separate species. Since it grows over such a wide geographical range, there is considerable variation in the wood’s colour, grain and texture. 

WTK_english-oak

It is a large deciduous tree growing up to 130 feet in height with a massive girth. Trees with a circumference of 36 feet have been reported.  Most modern trees average 12 to 15 feet in circumference. English Oak matures slowly; usually taking 150 years before harvesting can begin. Some specimens have attained 1,000 years of age with the oldest oaks approaching 1,500 years.
 
Like most of the white oak family, the wood is hard and durable. The heartwood is a light to medium brown, while the sapwood is lighter in tone occasionally blending into the heart. It is straight grained with a coarse uneven texture. Variation in growing conditions can produce interlocked and irregular grain. The density of growth rings is also highly variable. English Oak has large medullary rays and they are very prominent and distinctive on the quarter-sawn surface.

WTK_english-oak-endgrain
English Oak end grain
 
English Oak has a high tannin content. These chemicals help make it rot resistant and durable. Air dried English Oak is an excellent candidate for steam bending.  Kiln drying must be done slowly to prevent honeycombing in the interior of the wood.
 
English Oak is a superior shipbuilding wood, and it is also an excellent choice for cabinetry. It is used for trim and millwork, is the preferred wood for barrels and cooperage as well as sliced into decorative veneers. English Oak will reward the woodworker who shows patience and finesse. Tools must be kept continuously sharp to work this hard and dense wood. Routing edges need multiple passes to prevent tear out and burning. When dressing rough material, care must be taken to prevent damaging the fragile medullary rays. Slower feed rates and perhaps sanding to final dimensions may be helpful. It glues well and the use of screws and nails will require pre-drilling. It is a premier wood for staining, and it is receptive to all common finishing techniques. 
 
The high tannin has important implications for the woodworker - one problematic and the other spectacular. Tannins will react to iron, especially in the presence of moisture to produce dark stains in the wood.  Woodworkers should be careful with metal clamps and when storing oak on metal racks. This propensity for staining also produces the extremely rare bog oak. Bog oak is English Oak that has been buried in peat bogs. The low oxygen levels preserve the timbers while the acidic environment allows iron and other salts to stain the wood an extremely rare and striking inky black colour.
 
English Oak can also be infected with a fungus that turns the wood a rich brown colour that so far has been impossible to duplicate by artificial stains. Once the tree is cut and dried, the fungus dies leaving the distinctive colouration. The process is inexact and natural. Some pieces will show a consistent colouration where others will possess a more random, mottled appearance. This results in a distinctly coloured pattern that will appeal to many woodworkers.
 
Since the European Oak is imported, the price is high and supply is limited in North America. The trees are usually cut using the Boule method, which can increase the waste factor and make it higher than that of North American Oaks. Bog and Brown oaks are rare and pricey.It can be easier to obtain these varieties in veneer. English Oak is a wood with a pedigree, excellent in all applications. Woodworkers should not let pricing discourage them from trying this historic species. 
 
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English brown oak, imbuya and maple showcase cabinet  by Jacques Breau
 
 
Average Dried Weight42 lbs/ft³A measure of its weight at 12% moisture and an ambient temperature of 70°F.
Specific Gravity.67A measure of the ratio of its density compared to water (at 12% MC)
ShrinkageRadial: 4.7
Tangential: 8.4
Volumetric: 13
Radial (the amount of crosswise shrinkage);
Tangential (the amount of lengthwise shrinkage);
Volumetric (the total amount of shrinkage.)
T/R Ratio1:8A measure of the uniformity of tangential to radial shrinkage.
Janka Hardness1,120 lbfA measure of resistance to denting and abrasion.
Crushing Strength6,720 lbf/in²A measure of compression strength parallel to the grain.
Colour
Heartwood is a light to medium brown. The sapwood is a lighter brown. Bog oak is a deep black. Brown oak has a distinctive brown colouring provided by a harmless fungus.
GrainUsually straight grained.
TextureCoarse uneven.
Workability
Rewards a patient approach. Tools must be sharp. Glues well and accepts fasteners when predrilled. Stains and finishes well. Beware staining from metal clamps
UsesExceptional cabinetry wood. Shipbuilding, trim, millwork, veneer and wine barrels.
Price$24.95/bf 4/4 lumber
 
  
Photos and Specifications Courtesy of: The Wood Database