Specialty moon wood 

General Feature and Characteristics of Tonewood

The highest criteria for wood are used for the building of musical instruments:

• Trunk wood free of any knots
• Straight grain (free of twists)
• Homogeneous wood (no tension wood)
• A uniform structure with tight annual rings ranging from 1-2 (3) mm
• Low ratio of late wood (less than 20-30% of the total growth ring.) This assures a light coloration of the wood.
• Light in weight (a low or middle specific weight under 0.450g/cm3) without being soft
• Stiffness: a high deformation resistance (elasticity model) very high in relation to weight
• Sound velocity in high relation to weight and at the same time a high degree of damping.
• Low resin content, no pitch pockets
• Uniform in appearance (no color variation)
• Sufficient dimensions for quarter sawing (trees with a diameter of more than 50 cm)
• If possible, a special sheen
• If possible, smooth, not brittle plane shavings

Wood from the Region of Bergün

In a large-scale study slated to test the importance of the timing of tree felling, Prof. Dr. Ernst Zürcher was able to compare simultaneously three locations, and partially a fourth location, over a period of several months. The test subject of Prof. Zürcher's detailed study was alpine spruce. One hundred forty-four trees from a natural, northerly-exposed stand (altitude between 1520 and 1580 meters) were studied. This spruce wood was then compared to wood of the same kind from another alpine stand and a stand of trees at a lower altitude. In each case, 144 trees were felled. The trees at the lower elevation came from artificially planted stands of trees of the same age and form.

The best trees are found at higher mountain elevations of over 1000 meters, typically on northern exposures where nutrient-poor soil and a cool climate promote a short growing season. Small mountain hollows and localized level areas sustain individual trees free of compression wood. These trees grow naturally in managed stands, benefiting from regular, but conservative, harvesting. They exhibit a narrow crown of smaller branches that drape the trunk. Occasionally spruce shows fine waves in the annual ring growth (bearclaw)

Based on scientific evidence from extensive material the following could be documented:

• During the drying process of the heartwood (used in the making of musical instruments) the moisture loss for the spruce from the Bergün region was clearly lower in relation to its green volume - an indication of drier wood.

• In the 24 weeks of testing, during which time trees were felled on 48 different days from October to March, a slight, but clear decrease in moisture loss was observed. As a rule moisture loss is subject to much less variation over time.

• Shrinkage (percentage of dimensional loss as a result of moisture loss) was, however, analogous to the shrinkage exhibited in the spruce from the other two locations.

• Considering the very tight ring spacing of the wood from Bergün, the oven dry weight (after laboratory-controlled drying at 103 °C) was exceptionally low - its total average practically identical to the weight of the samples from the other two locations where the spruce showed wider annular ring spacing.

• Moisture absorption tests with already dry wood samples were surprisingly informative. Wood from Bergün clearly absorbed less water, both in one-week submersion tests and in capillary testing (absorption through dowel-shaped samples.)

• This characteristic could be of some importance considering the changing climatic and humidity conditions to which musical instruments are exposed. 

The Importance of Lunar Cycles and Position as They Relate to the Felling of Trees and Wood Characteristics

What is moon wood? 

The encyclopedia defines moon wood, as wood that, according to tradition, exhibits outstanding and unique characteristics when felled during a certain phases of the moon.

For centuries lumber was cut exclusively in the winter and then only at certain times in accordance with the phases of the moon. Specific, moon-related felling guidelines passed down through generations have apparently proved useful for other professions in the timber industry.

The goal of this study, encompassing various regions throughout Switzerland, was to determine scientifically whether variations in wood characteristics could be determined in connection with lunar cycles. Criteria such as moisture loss, shrinkage, and relative weight (the ratio of oven dry weight to green volume) were specifically analyzed by using individual samples.

For time being, the following conclusions can be summarized:

• The amalgam of the data material (with the aim of forming overall trends for the alpine regions of Switzerland) and the use of specific, statistic-based analysis allow for a determination of significant (statistically relevant) lunar oriented components in the variability of moisture loss, shrinkage and relative weight.
• It was determined that the division waxing (from new moon to full moon) and waning (from full moon to new moon) points to significant, across-the-board differences in shrinkage, but final results are still outstanding. The data analysis permits two precise, systematic, lunar orientated divisions that apply much more precisely to all three criteria.
• The variation spectrum was not, however, totally attributed to the position of the moon. The inclusion of the reference weight (taken before felling) of each individual tree, independent of time, shows that this factor plays a superordinate role, but confirms the significance of the lunar models tested.

Experiences of a Swiss Violin builder