Urushi

I’ve been looking forward to this part of the apprenticeship for a long time, well before the program, in fact, not only because I practice kintsugi and am familiar with using urushi, but because I’ve known there is a method of finishing wood with urushi that produces a whole range of finished looks that are completely natural, food safe, resilient, durable, and aesthetically stunning.

When I say “finishing” I mean applying a finishing coat of urushi. And when I say “urushi” I mean raw lacquer, the natural sap from the lacquer tree that grows throughout Asia (see below). This is not to be confused with lacquer as we know it in the west, a man-made product composed of synthetic polymers, and that is also used for finishing wood products. In this program, we are going to learn how to finish our wood products using natural lacquer, which in Japanese is called urushi.

The technique is called fuki–urushi and means to wipe on lacquer. And that’s what I’ve been wanting to learn for a long time. The reason we’re learning it in this program is because the box we’re making is actually a bento lunch box. The small compartments on the inside are going to come into contact with food, and that means they need to be protected with a food safe finish. While a simple beeswax or salad bowl finish would suffice, urushi embodies the craft and enduring beauty that is far more suitable for our sashimono apprenticeship.

This is a real sample of a section of a lacquer tree, approximately 15 years old. Each incision releases about 1 – 3 grams of urushi. The incisions are spaced out by 4 days each and are cut in multiple sections at a time over a 4 month period. Only about 200g can be obtained from one tree before it is cut down and repurposed as fire wood or other creative means. At “Und” they make quite a few different lacquer tree wood products.

A traditional basin for mixing and refining raw urushi

The process of fuki-urushi was actually quite simple, especially because we had a very experienced teacher guiding us today. His name is Taku (see above) and he’s a fourth generation urushi refiner. He and his wife run an urushi business called “Und” where we participated in the fuki-urushi workshop today. After teaching us all about lacquer and giving us a tour of his refinery, he showed us how to mix raw lacquer with natural turpentine in order to thin it out· so that it can penetrate the pores of the Paulownia wood. After applying the thinned lacquer, we wipe off any excess, not unlike applying other kinds of wood stains. The initial colour is very light brown but after placed in a controlled environment of around 25 degrees celcius and 75% humidity, the colour darkens significantly in less than 24 hours (as seen below.)

These conditions are very important for the lacquer to harden or cure properly. Unlike synthetic finishes that dry, raw lacquer will harden or polymerize slowly under these ideal conditions, and will continue to strengthen over time.

Any of the allergenic properties present in its raw form will be gone after sufficient time in these ideal conditions, making it eventually food safe. Taku said we could add subsequent coats, with light sanding in between, using progressively higher and higher grits of sandpaper. It will develop a deep, warm sheen that maintains the texture and highlights the grain of the wood. I plan to apply at least 2 more coats.

Taku is also making an effort to grow more lacquer trees in Japan to secure this treasure for generations to come. Between his refinery work, workshops, high-end retail space, all of the education he offers, and the way he collaborates with countless other artists, he’s doing an impeccable job to preserve this beautiful lacquer craft. I’m certainly excited to learn more about it and to incorporate what he taught me into more of my woodworking.