Urushi

 

Urushi work involves the use of the sap of the urushi tree to make, lacquer and decorate objects. 

The first step is the gathering of the urushi sap that flows in the xylem between bark and trunk. It seeps out when cuts are made in the bark using a special sickle and is scraped into a small bucket. The sap is milky white at first, but changes to a light brown on exposure to the outside air.

Usually gathering urushi sap is done from the middle of June to the end of October. The character of the sap is defferent from the gathering season or the place.

The quantity of the gathered sap is only 200g for a year. Urushi sap is really precious and fulls of cares.

 

Generally speaking, urushi hardens at a temperature of 25 and a relative humidity of 70%.

As well as hardening at room temperature, urushi has another hardening point at the higher temperature of 80-150. High-temperature hardening of urushi is used on ceramic and metal items, for example inside cast iron tea ceremony kettles. Once it has hardened, urushi is extremely resistant to water, heat, acids and alkalis and protects the body to which it has been applied. Its viscosity also makes it an excellent adhesive.

My gathering experience in Okayama  Aug'99

The three main features of urushi are its viscosity, long hardening time and gloss. The beautiful lustre of hardened urushi is what makes it so special, and the various decorative techniques applied to the final gloss layer are only possible because of urushi's extended hardening time and viscosity, which allow the drawing of long fine lines.

 

Recently urushi wares are proved that they are more durability and sterilizing power.

 

 

 

 

Urushi rash

 

Urushi is botanically related to the poison ivy plant.

Urushi can cause an allergic rash and dermatitis when liquid.

The allergic reaction due to contact with poison ivy is from the urushiol oil (pronounced oo-roo-she-ol from urushi, the Japanese word for lacquer) contained in all parts of the plant except the anthers (pollen) and the wood cells (honey from poison ivy is harmless). 

Fully dried urushi can't cause it.

 

The dermatitis is often serious.
Swelling and itching last for a while. It depends on the person how long or serious.

If the part of the rash has not scratched, it would become as before without scars. And the person becomes immune from urushi. The immunity is hereditary.

 

 

 

 

How to care of Urushi wares

 

Washing

Urushi wares are washed by water or warm waterwith a synthetic detergent.

After washing, wipe them by a soft cloth then put in order.

You shouldn't pile with ceramics or potterys because it sometimes results in cracks.

Also don't soak them in water for a long time.

 

You don't have to pay attention to casual wares. Just avoid using a microwave or

a dishwasher. Urushi wares are durable basically.

Regarding to precious pieces, you had better keep a constant temperature and humidity. Also UV should be kept away. It's extremely bad to urushi things.

It depends on the pieces how careful to treat them.

 

New pieces

Urushi takes about 6 months to dried completely inside.

You had not better use new urushi wares at once.

If you put it aside for a while, the surface would be getting harder and damaging or the change of the color would be getting rare.

Sometimes new urushi pieces have got a peculiar smell.

Considering these things, new pieces should be taken out from their boxes and be put aside on the shelf keeping away from UV.