When I speak of wood selection here, I limit myself to describing the woods I work with: spruce and sycamore maple. Both woods have been used for centuries in instrument making and can be found in our native forests. I consciously refrain from the botanical description, for this I like to refer to the wood encyclopedias that can be found in the Internet. The question is, which trees are suitable and which are not? Where can I get such wood? In what quantities? The following are pictures from a professional timber company:
Traditionally used for centuries, spruce wood comes from the mountain forests of Central and Western Europe. Its range extends from the Jura Mountains to the Romanian Carpathians (France, Switzerland, Austria, Italy, Germany, Czech Republic, Slovakia, Slovenia, Poland, Romania, Russia, Ukraine).
The most favorable locations for the Klangholz
- are located in the mountains (reduced growth rate and low proportion of late wood)
- ensure regular water supply during the growing season (regular growth)
- are more or less protected from the wind (no compression wood, no cracks or resin pockets)
- are not too steep (no compression wood)
The most favorable altitude for the growth of the sound wood depends on the climate and topography.
- Italian Southern Alps: from 1000 to 1300 m
- Upper Bavaria, Northern Alps: from 800 to 1300 m
- Swiss and French Jura: from 1000 to 1300 m
- Carpathians and Bohemia: from 800 to 1200 m
- Ore Mountains 650 to 900 m
Of course, you can't just go into a mountain forest and cut down a tree, in Germany (in neighboring European countries it will probably be similar) there are various options. One is to go directly to the producer (forester) or to a dealer who has already purchased and sorted the desired assortment (wholesaler). Timber growing (production) is often in state hands, forestry offices sell the timber. If the forests are privately owned, the forest farmers have often joined together in forest farmers' associations which sell the wood. Wholesalers purchase the wood from them.
Forestry is normally seasonal and the majority of timber trade takes place in the winter half of the year, because in this period the normal harvesting economy rests and the farmer cuts timber according to tradtition. Timber prices for different qualities of use are kept in a narrow band. Forestry offices determine average prices, which then hardly change. Thus, any quantity of normal quality wood sells throughout the year. Prices directly from the producer are of course cheaper than from the wholesaler. However, the wholesaler also represents a value through his services (sorting, transport, sawmill, etc.).
In addition to direct purchase, it is also possible to buy logs at timber auctions. If a log turns out to be particularly good, the forestry offices or forest farmers' associations try to achieve a higher price by auctioning off the individual logs. For this purpose, several hundred individual logs are often lined up together and numbered at large timber collection points, usually in the spring. Upon request, commercial bulk buyers receive lists on which the log number, the type of wood, the dimensions and the quality are noted. The interested party bids by submitting a list of bids, on which he notes the price he is willing to pay per cubic meter of timber. These lists must be received sealed in an envelope by the deadline of the bidding. At the opening of bids, the respective bids for the log number are compared and the bid is awarded to the party willing to pay the highest price for it. A subsequent bid increase is not possible.
For Bavarian mountain spruce
as tone wood from wholesalers:.. currently 500-1100 € / m³
as valuable timber from the producer:.. currently 40-500 € / m³
Skidding / Transport
per ordinary (in small numbers) 50-80 €
often charged per cubic meter, make up beforehand, otherwise per hour on the band saw between 45-80 €
(an interesting comparison numbers from a Canadian study)
|Species||Master cost||Unit volume||Spreaders|
|Sitka Spruce||700-800 $ / m³||1 m³||150-200 Top|
|General Spruce||170-250 $ / m³||1 m³||60-80 Top|
Age at least 120-150 years, better 250 years. Latewood proportion uniform and low. Diameter of the trunk from 60 cm. Depending on the amount of wood cut, trunk thicknesses from 85-90 cm are required for large guitar tops by radial cutting.
Trunk part is considered usable clay wood if it grew at least 5m above the ground. Logs as free of knots as possible. According to the TLG of the GDR, there were to be no knots in the best quality (K1) per 2 meters length. Examine cut surface for knot ends, possibly evidence of value wood loading.
Spacing of annual rings between 1-1.5mm for top quality. Uniformity between early and late wood, i.e. spacing between annual rings is uniform.
Shine as white and mirror-like as possible. No color changes.
The wood should be cut lunar in December new moon. It is said that lunar cut wood, which was stored downhill until spring, is particularly good. If one waits until the tree tries to build up new shoots and only then cuts the branches, one should have a dehumidified and dehumidified tree trunk, which sounds particularly good.
Under the bark:
Another quality criterion is the structure of the log under the bark. Small scar-like grooves indicate stiff, good tonewood. Often, such logs also have lively hazel growth.
The following wood defects severely limit its usability to tonewood:
Knottieness: Tone wood must be free of knots! Small knots and knotlets may be located where they fall away after cutting for use. However, care must be taken that the evasive growth of the wood fibers around the defects is not too great.
Rotational growth : If the growth direction changes from straight from the bottom to the top in such a way that the fibers follow upwards, similar to a thread of a screw, this is called rotational growth. Very well recognizable in debarked spruce logs (observe natural wood cracks). The wood grown in this way has created tension in the growth and cannot be calmed by splitting and long storage. It "throws." Cut and planed surfaces of such wood have much more fibers cut than straight grown wood.
Damage due to human intervention : Probably the most annoying mistake is called nail or barbed wire! If the saw blade hits an ingrown piece of steel, the saw immediately loses its sharpness! Most often, you can hear the sawyer swear strongly, then a new blade must be sharpened and mounted. Depending on the damage, the sawyer charges e.g. per nail 35-70€!
Irregular annual rings : Normally, over 75% of the clay wood surface, the growth of the annual rings should be uniform. Strongly different growth makes the wood throw and it warps. Wood with irregular annual rings should be rejected.
Eccentric growth: If a tree trunk does not build up its annual rings evenly layer by layer around the center of the trunk, but the layer thicknesses on one side are considerably thicker than on the other side, this results in an eccentric growth. This can be recognized by the slightly oval log cross-section and by the fact that the wide annual rings are usually very hard and brittle (redwood). It will warp strongly and it cracks easily. Eccentric growth often occurs in trees that have been exposed to strong winds on one side or were standing crooked.
Weather damage : If the tree is damaged by lightning, heavy frost (wound wood) or strong wind (breakage) during storms and the tree can "enclose" the wounds, these growth changes have a strong disturbing effect on the tone wood quality.
Resin pockets : Not in hardwoods, hardly in firs, but strongly in spruces. These are small "resin lakes" along the annual rings. When these areas dry or empty, voids remain, weakening the wood and hindering sound transmission. Emptying resin pockets clog saw blades in no time!
Color changes of the core : If the wood cells of some tree species are no longer in direct nutrient flow, the color of the core changes (beech, ash). Besides these harmless species, color changes due to decay threaten the wood quality considerably. Spruce is often attacked by red rot. The otherwise light-colored felling wood parts of the annual rings become reddish, in the advanced stage the trunk crumbles, the wood is spongy. Other bacteria and fungi cause cankers, heartwood fungi cause green streaking in maple, for example. Damaged areas must be removed for storage, unaffected trunk parts can be further used.
If the tree is not yet felled, it is very easy to see abnormalities in the leaves and bark. Are the leaves discolored, are all parts of the tree in sap? Is the tree heavily mossy, do many lichens or resin exudates adhere to the bark?
If the tree has been cut down, look at the cut surface (with a plane or even a chainsaw, you can uncover unsightly areas). Around the tree, look at the bark and look for changes. There are also people who hold a tuning fork to the wood. If one knocks on the trunk with a small hammer, a first statement about the damping quality can also be made here. What does the annual ring structure look like? Knottiness, rotational growth....
But you can only really tell after sawing!
So what do really beautiful pieces look like in practice? Summarized it is in the picture:
This is what a cream spruce looks like from the side:
beautifully pronounced hazel growth.
Straight fiber and uniform growth
In the sycamore maple also opens up beautiful grains