Trade Names
Walnut Burl, Californian Walnut Burl
Latin Names
Juglans nigra (with Juglans regia graft on)
Origin
West coast of the USA from Southern California to Oregon.
Range
The burl is only a “by-product”, the actual purpose of the tree is to grow nuts. To this end gigantic walnut plantations have been set up where the European Walnut (Juglans nigra) is being grafted the American Walnut (Juglans regia). As a result root burl growth develops below the grafting point. After the productive capacity of the trees for nuts has been exhausted these burls are dug up as a second product and sold.
Uses
Highest quality interior work and furniture production. Used in larger quantities for dashboards by the automobile industry. Also used for high quality instruments in the production of upright and grand pianos. Most desirable as solid wood for gearshift knobs.
Properties
Walnut burl occurs in many different forms. From head veneer and cluster to solid burl which now as before numbers amongst the most expensive and most sought after veneers. Splitting often occurs within the trunk.
Machining
The wood is easy to work with all hand and machine tools.
Seasoning
The burly texture calls for extremely slow and careful drying to keep tension in the wood as low as possible. Mechanical machining also requires the greatest of care to prevent surface fibre pick-up. The texture of the burl is highlighted best by high gloss varnishes and polishing.
Finishing
The very smooth surface takes all stains well, particularly water and nitro stains. The wood polishes well when fillers are used.
Jointing
Joints using screws, nails and glues are easy to produce and have normal tensile strength.