60th Anniversary Exhibition of Kagawa Prefecture lacquer Institute has been held.

Originally lacquer coating strongly robust heat and humidity, because it is resistant to acid and alkali, and has been used as paints and adhesives and waterproofing agents.

In addition, Urushi is provided with a unique texture and luster, unique beauty is consistent with the aesthetics of Japanese, many of lacquer ware has been created.

Lacquer ware completed through green body process to create a foundation and the underlying process for shaping the green body, coating step of repaint the lacquer on the underlying surface, the process over the long trouble of decorating process to put the pattern on the lacquer surface.

urushi

Recently, chemical paint has been used as an indoor paint, but can cause sick house syndrome by solvent evaporates. Lacquer has the property of drying themselves unlike science paint. Also, once it completely dry, you do not have poison ivy. Lacquer is as natural paints, has been attracting attention as health friendly paint of environment and people.

How the lacquer to dry (the lacquer dries as fast as the day of rain)

Lacquer of the main component is a resin content of urushiol.

The ratio of urushiol ingredient rises as good lacquer.

Temperature if become humid, an enzyme (laccase) included in the urushiol is activated, and take in oxygen from atmospheric water, and, by an oxidation reaction with the urushiol, constitute a huge macromolecule of the halftone plate structure scientifically.

It changes from a liquid into a solid on the appearance.

It is said, "lacquer dries" in this course.

The lacquered drying is not a phenomenon that water evaporates and dries, and it means that an enzyme makes a macromolecule.

Temperature (around 25 degrees) and the humidity (around 75%) necessary to let an enzyme activate are necessary so that lacquer dries.

Therefore the lacquer dries early because an oxidation reaction promotes it as the season of high temperature and humidity in the rainy season.

 The lacquer dries early as a day of the rainy weather.

 It becomes sealing up structure that the lacquer bath puts the board of a hinoki and the cedar and enhances protection against dust, thermal insulation, an effect of the humidity retention, and temperature and the humidity that are most suitable for lacquered drying come to be found.

【漆が乾燥するしくみ（雨天の日ほど早く乾く）】
漆の主成分はウルシオールという樹脂分で、フェノール系の物質。上等な漆ほどウルシオール成分の割合は高くなります。温度や湿度が高くなると、ウルシオール中に含まれている酵素（ラッカーゼという）が活性化し、空気中の水分から酸素を取り込み、ウルシオールとの酸化反応によって、科学的には網目構造の巨大な高分子を構成します。外見上では液体から固体へと変化します。この課程を「漆が乾く」といいます。漆の乾燥とは、水分が蒸発して乾くという現象でなく、酵素が高分子を作るということです。

漆が乾くためには、酵素を活性化させるために必要な温度（25度程度）と湿度（75%程度）が必要です。そのため、梅雨時の高温多湿の季節ほど酸化反応が促進するので、漆は早く乾燥します。雨天の日ほど漆は早く乾燥するのです。漆風呂（うるしぶろ）は檜や杉の板を貼って防塵、保温、保湿の効果を高める密閉構造になっており、漆の乾燥に最適な温度と湿度が確保されるようになっています。

Tapping lacquer

[Tapping lacquer]

Tapping lacquer means craftsman damages the lacquered tree trunk which grew up and repeat picking the sap which oozed out.

This work is performed from about the middle of June through the end of October while watching weather and the situation of the tree.

§  　　In the Middle Ages, common people must put the lacquer as a tribute like rice, silk and those were recorded an investigation to a place and the number that the lacquered tree grew at a government office.

It stirs the KIURUSHI which removed small pieces of wood from the gathered lacquer, and do an ingredient homogeneously; "NAYASHI". Next, it heats and vaporize water "KUROME", it is to refinement lacquer with the viscosity in semitransparent reddish yellow.

It becomes the vermilion lacquer when you add red colors such as the red ocher to purified lacquer and it becomes the black lacquer when you add, iron powder and iron hydroxide. Many wooden bowls or bowls are made with vermilion lacquer and black lacquer.

Recommend video 

http://www.youtube.com/watch?v=87dGyvRCKAM

【漆掻き】
成長した漆の木の幹に傷をつけ、にじみ出てきた樹液を掻き採る作業を繰り返します。この作業を漆掻きといいます。この作業は、6月中旬頃から10月下旬にかけて、天候と木の状況を見ながら行われます。

中世では、漆は米・絹などと同様、年貢として納めなければならないものであり、漆の木の生えている場所と本数までも役所で調査・記録されていました。 採取した漆から木屑等を取り除いた生漆を攪拌して成分を均質にする「なやし」、加熱して水分を蒸発させる「くろめ」の作業を行うと、半透明の飴色で粘度のある精製漆になります。精製漆にベンガラ等の赤色顔料を加えると朱漆、鉄粉や水酸化鉄を加えると黒漆になり、朱漆と黒漆を使って多くの椀や鉢などが作られます。

Refinement of Japanese lacquer

【漆の精製】
漆の木から採取したままの漆は、木屑やごみなどが入っているうえ、質が均一でなく、水分が多すぎます。攪拌機（かくはんき）でかきまぜながら、熱を加えて水分を少なくします。それが漆の精製です。精製することによって、漆の用途は広がります。
木屑やごみをろ過したものを生漆（きうるし）と呼びます。


The lacquer gathering from a lacquered tree are contained some small piece of wood or garbage and quality is not equality with a high water. It add heat and reduce water while stirring it with a stirrer. It is the lacquered refinement. The lacquered use spreads by being refined.
It is called “KIURUSHI” which filtered a small piece of wood and garbage.



I found the movie about refinement of Japanese lacquer from youtube.

http://www.youtube.com/watch?v=LiZpDblfRT4