Urushi - The origins
Urushi is the Japanese word for laquer that is derived from the sap of the paint tree " Rhus Verniciflua Stokes ".
For more than 3000 years this organic natural lacquer has been used for the production and decoration of art and utensils in the entire Chinese-Asian region.
Over thousands of years, Japanese craftsmen in particular have brought this art form to its full potential and developed thousands of techniques and methods of varnishing, most of which are very
complex and time-consuming and are still carried out today in the same way as then.
Harvesting
As an organic varnish, of purely natural origin, Urushi is still harvested by hand from the varnish tree today.
The profession of lacquer harvesting ("Urushi - Kaki") is an independent profession in Japan.
One working day a Kakiko ("scratcher" - "harvester") can harvest about 2 liters of raw varnish from 150 trees - that corresponds to less than 15 ml per tree on average. The working time for this is 15 hours per day.
This in combination with the long refining process ("kurome & nayashi"), in which the water concentration is reduced from 30% to 3% and the various varnish substances are homogenized after filtering, is the main reason for the high price of Urushi.
The price of Urushi varies greatly due to many different varieties that vary depending on harvest time, place, composition.
High quality Japanese Uruhsi is between gold and silver in gram price, which makes it a very valuable material and the most precious lacquer available.
Processing and
In recent years Urushi has defied all attempts, to modernise its processing (for example by air pistols or other tools, or the acceleration of the complicated hardening process, which is not a drying process but an enzymatic hardening process, failed completely), as it is not a single pure chemical substance with clearly defined physical properties.
Even today, the only possible application is the traditional one that has been used for hundreds of years.
Urushi is applied by hand with special high-quality brushes (traditional Japanese brushes consist of fine Japanese woman's hair) in many wafer-thin layers, each of which must be completely hardened.
Various additives, which are also 100% natural and of high quality, such as balsam pine terpentine, orange oil and camellia oil are used.
These are used for thinning, polishing or cleaning the brushes.
While Japanese masters often use between 30 and 100 layers of lacquer in very decorative styles - e.g. the Maki-E "gold picture" - a very decorative style where gold powder is sprinkled on the still wet varnish to create images - apply,
for sound reasons, only simple painting techniques with a considerably thinner layer thickness are used for the LUNA Handpan.
These create a completely smooth, calm surface from which the sound can emerge unbroken.
Even after 6 years of working with Urushi, the fascination about the possibilities and depth this material offers, and the craftsmanship experience its processing requires, does not diminish.
Physical properties of Urushi
LUNA-Handpans are the world's first and for the time being only Handpans painted with Urushi.
Since Urushi is still largely unknown to the general public in our European culture, I would like to inform you a little about its properties and effects on the sound of Handpans.
In contrast to synthetic varnishes, which are not suitable for the coating of a Handpan, as they dampen the sound considerably, Urushi has physical properties, which predestine it for use on ideophonic steel instruments such as the handpan.
The effect of these properties can be seen above all in the overtones and the clear, long sustain of the LUNA:
- The hardness. Urushi achieves a hardness of 5.5 on the Mohs scale when properly cured, which is almost as hard as glass.
Converted, this is about 600 kp/mm2 on the Vickers scale.
For comparison: nitrided steel only has a Vickers hardness of approx. 400 kp/mm2 !
- During hardening Urushi remains permanently flexible, which is of great importance for the Handpan and its sound.
The average modulus of elasticity of Urushi is between 1000 and 2000 MPs with a tensile strength of about 40MPs.
This in combination with an elongation at break of approx. 5.8% makes it suitable not only for the coating of Handpans, but also after the varnish application, warranties a problem-free tuning.
- Urushi is chemically highly resistant when cured.
It is absolutely resistant to water, alcohol as well as acids (hand perspiration!) and bases, and thus offers ideal protection for the Handpan.
- In addition to these scientific properties, however, the beauty in optics and haptics weighs particularly heavily.
With Urushi you no longer touch a metallic surface when playing LUNA, but an organic one.