SPANISH WALNUT

Technological properties

Walnut wood is lighter than beech. Walnut is dried slowly, requiring care, but once it is dry it is quite stable. There is risk of deformations arising, of internal cracks appearing and of collapse occurring in thick pieces if the progress of drying is forced.

Sawing is difficult due to its hardness, the presence of knots, the irregularity of pieces and other flaws. The performance obtained is not very high. For these reasons, a large percentage of the wood is used for products with lesser performance.

The wood is not suitable for obtaining rolled veneer due to its hardness and its texture. It is suitable for obtaining sliced veneer.

It is easy to work on, is characterised by its excellent finish, and is easy to machine. Repelling may occur during brushing. Blunting of tools is normal. It is good for curving.

Gluing does not pose a problem, but alkaline glues must be avoided (such as casein glues) which are susceptible to reacting with the tannins and causing stains. It is easily nailed and screwed. The finish does not pose difficulties.

Origin and availability

It is found in the south east of Europe (Spain, France, Italy, Yugoslavia, Greece, Bulgaria), in the west of Asia (Turkey, Armenia, northern Iran), in the north east of India and in the Himalayas.

Description of the wood

Walnut is a medium sized tree, from 20 to 30m tall, important for its nuts and its wood.

European walnut wood is greyish brown, with black grain, and is generally more variable than American walnut, which is typically a dark, uniform reddish brown colour. The thick or coarse grain is straight, occasionally slightly wavy, with a medium texture.

The colour of the sapwood varies from grey to light brown, and the heartwood from greyish brown to grey. It has very dark coloured grain with a tendency towards black. The sapwood is clearly distinguished, and the wood rays are more or less discontinuous lines of a whitish colour, and difficult to notice. The growth rings are not prominent.

The fibre is normally straight, occasionally slightly wavy.

Through baking it acquires an attractive reddish colour, while highlighting the grain.

Natural durability

It is moderately resistant to fungi. It is classified as moderately durable against fungi and sensitive to anobiidae, powderpost beetles and termites. The heartwood has low penetrability and the sapwood is penetrable.

Applications and use

The bark is rich in tannins used as a tanning agent for dyeing

It is not used outdoors due to its medium durability. It is widely used in the butts of firearms, such as those used by the allied armies in the first world war, which were made of Spanish walnut.

The tree has a very closed treetop, which releases a large amount of tannins when it rains. These tannins have a strong odour which causes headaches among people who spend a long time under the tree. This is the origin of the legends which circulate about the harmfulness of the shadow of the walnut tree.

It is one of the most decorative woods in the world, used since antiquity for the manufacture of furniture. Today, walnut is mainly used as a veneer for the manufacture of furniture and for coverings, as solid wood used in luxury carpentry and for the manufacture of bowling pins and other turned items, and is the preferred wood for the butts of revolvers and shotguns. Other uses: Doors, Floors and parquets, Friezes, Mouldings, Staircases, Sports items, Pianos, Handicrafts, Carving and Engraving, Roads, Firewood, Charcoal and Curved pieces.