Loading... Please wait...
shop by

Browse by Tag

Japanese Finishing Trowels




History of Japanese Trowels

Strangely enough, the story of Japanese trowels and exquisite plastering begins with tea and fire.

Tea and the Japanese aesthetic

Between the 9th and 13th centuries, Buddhist monks brought tea seeds from China to Japan and in the 16th century, Zen practitioner Sen no Rikyu, established the tea ceremony. The tea ceremony generally takes place in a chashitsu, or tea house. More than 400 years ago, Sen no Rikyu plastered the walls of his tea house with local, native soils, and forever changed the course of history.  To this day, following the Japanese aesthetic of "wabi-sabi", the unostentatious walls of the chashitu are plastered with earth. As the tea ceremony and the construction of tea houses spread throughout Japan, the art of Japanese earthen plastering flourished. Unlimited time and resources were granted to craftsmen to create unpretentious, but exquisite earthen plastered walls. In this way, tea and the Japanese aesthetic led to the high development of fine earthen plastering in Japan.

Fire, fear and awe

Like many traditional societies, in Japan, fire was something to be feared and awed. Since most traditional Japanese buildings consist of a wooden structure, the danger of fire was ever present. In order to safeguard valuables and food rations, thick earthen plastered storehouses, known as kura or dozo, were built. The massive earthen walls of these buildings protect valuables from fire and food stuffs from rodents and temperature extremes. However, Japan also experiences high precipitation. In order to protect the earthen walls from weathering, storehouses were often finished with a thin coat of Japanese lime plaster . In a sense, the fear and awe of fire led to the development of massive earthen plastered walls in Japan, and high precipitation led to the development of fine Japanese lime plastering. 

Through tea and fire, we see two streams of natural plastering in Japan, fine finishes to be appreciated and functional massive earthen walls for protection.

Concomitant with the spread of natural plastering in Japan, trowels were developed for various purposes. At the end of the Edo period, with the dissolution of the samurai class, the production of swords was forbidden.  Highly skilled sword black smiths, in turn, shifted their emphasis to carpentry and plastering tools.  To this day, Japan is known for its exquisite carpentry and plastering tools.  With over 100 different types of trowels, Japan probably hosts the largest variety of trowels on the planet. But unfortunately, with the spread of mass produced commercial building materials and tools, the demand for hand forged trowels has decreased. And as a result, the number of craftsmen who produce these fine tools are dying.

There are two general types of trowels: Nakakubi and Motokubi.
Nakakubi trowels are typical Japanese trowels, held with the neck attaching the handle and plate between the forefinger and middle finger.

Motokubi trowels consist of a single piece of steel, with the neck held between the thumb and forefinger.
Motokubi trowels are historically older.  Along with the introduction of western cement mortars, Nakabuki trowels were first invented around the end of the 1700's and came into popular use around the end of the 1800's. 

A primer on Japanese steel

Originating from the culture of sword making, forging metal in Japan is a fine art. Trowels are produced from steel of various temperaments, ranging from "soft" iron known as jigane to "hard" high carbon steel known as honyaki (literally fully fired). Between these two extremes are a variety of steels including hanyaki (literally half fired) and aburayaki (literally fired with oil).

Choosing the right steel for you depends on your purpose:

Jigane is unfired forged iron. Whereas a hard carbon steel tends to slide over a plaster, "soft" jigane iron will push and pull material, making it excellent at distributing plaster on wall. By "soft", we refer to the quality of the steel, not the flexibility of the trowel.  Because Jigane is a soft steel, Jigane trowels tend to be thick, stiff and heavy.  Jigane is suitable for scratch and brown coats of earthen or lime plaster.

Hanyaki is fired once after forging. Hanyaki is suitable for all coats, and can also be used for cement based plasters as well.

Abarayaki is steel that is forged, coated with oil, and then fired twice. It is harder than hanyaki and suitable for compressing plaster for a glossy finish.

Honyaki is made in a similar fashion to abarayaki, but is fired at a higher temperature. Being a very hard carbon steel, it is suitable for earthen or lime finish coats and cement based plasters.

Stainless steel is a relatively hard steel but can be produced so thin as to be flexible as well. Thin stainless steel trowels are used to apply thin coats and to smooth trowels marks. Only stainless steel trowels should be used with gypsum and synthetic plasters.

Forging a Trowel by Hand

1.      Cut the steel: Steel for both the trowel plate and neck are cut.

2.      Forge and shape the steel plate.
3.      Open the hole for the neck: The neck connects the plate and handle.

4.      Forge and shape the neck and neck hole: The physical pressure applied to trowels differs according to the size of the trowel, the plaster and intended finish.  The neck and hole are sized to maintain their shape under the force and pressure of application and compression.

5.      Remove the barbs from the steel

6.      Normalize, heat and quench the steel: The steel is heated to 1200.

7.      Temper the steel: Depending on the desired temperament (Honyaki, Aburayaki, Hanyaki or Jigane), the plate is tempered.
8.      Adjust the shape
9.      Smooth the steel with a grindstone and coarse sandpaper
10.   Swage the neck into the plate: The neck is pounded to form to, and connected with, the plate.

11.   Polish the trowel with fine sandpaper

12.   Treat the steel with a protective coating to prevent rusting while in storage: This coating is removed before use or naturally wears off during use.

13.   Attach the wood handle.

Traditional steels will rust if not cared for properly. Trowels should be cleaned and dried immediately after each use. When storing trowels for an extended period of time, they should be oiled to prevent rusting. In order to prevent the remaining oil from discoloring subsequent plasters, remove oil with a rag before plastering.







View Cart Go To Checkout