Trade Names
European Birch, Norway Burl, Karelian Burl, Karelian Birch, Alpine Burl
Latin Names
Betula alba
Origin
Northern Europe
Range
Birch Burl logs are primarily found in Central to East Finland and also in Russia (Karelia) in the extensive Birch forest stands there. However, it is always a case of just odd trees which have developed this special form of growth. It is either genetic or caused by the soil conditions and the location. There are strict felling quotas in Finland which are stringently controlled. As a general rule the usable length for veneer is from 50 cm to 150 cm. To be considered as absolutely rare are usable logs of 200 cm to 300 cm in length. Due to their small diameter Birch Burl logs are rotary cut. This is why the width of the veneer sheets is generally greater than their length. One log rarely yields more than 3 - 4 bundles.
Uses
High quality architectural woodwork.
Properties
The burl form is not the usual kind of burl development but generally shows a firmly ingrown pattern of many small, black deposits (eyes). These are spread more or less regularly over the surface of the veneer thus producing the attractive pattern.
Machining
The wood can be worked well and easily with all tools. Planed surfaces are very smooth.
Seasoning
Birch Burl calls for very slow and careful drying to keep tension checking and warping at the lowest possible level. Perfect tools prevent fibre pick-up on the surfaces.
Finishing
Surface treatment causes no difficulties.
Jointing
Glue is taken well by Birch Burl and joints hold well. Screw and nail joints should be pre-drilled.