Monday, January 15, 2007
Dai making explained in Taiwan
But while the main blade was important (and still is), the dai are made locally. The red oak used is of excellent quality and the one found nowadays has been left drying for several years, up to more than 10 years.
The dai made in Taiwan had followed the Japanese way, that is it has grooves allowing the main blade to be secured in place even without a subblade. But then the dai began to be cut without the grooves, requiring a subblade to hold the blade. This is the way it is done in China for example, in Europe also and in the USA for wooden planes.
A Taiwanese dai maker explained me that the pin maintaining the subblade began to be much thicker and tougher. He also said that the Japanese way was more challenging to make.
During the grand opening of a woodworking school, where I am a part time student (class on saturdays), I decided to finish the dai I had started few time ago. It would be a good occasion to explain where are the differences between Taiwan planes and Japanese planes.
This dai has a 66degree blade angle. I chose a high angle because the wood found in Taiwan ranges from hinoki (chamaecyparis obtusa formosana, ch. formosensis) to acacia (acacia confusa), and the later is very difficult to plane. The grain goes in all directions, and when dry, the wood is tough and relatively hard (harder than oak for heart wood).
The main plane is a "miki" blade from Tsunesaburo. The steel is hap40, a particular HSS steel and should be tough and hard enough for this intended use (high angle and hard wood). It has good resistance to wear. Hap40 is made by hitachi and has equivalents from other manufacturers. Its indicative content is:
C: 1.28 mass%, Cr: 4.21 mass%, W: 6.63 mass%, Mo: 4.57 mass%, V: 3.03 mass% and Co: 7.5
Miki blades or complete planes are available from Japanese tools Iida.
Dai making explained to Taiwanese amateur woodworkers