Through Genki-san’s recommendation, I visited a traditional tool shop in the northeastern part of Tokyo that specializes in high-quality woodworking tools. The visit was enriching, almost like a spiritual experience. I visited with the owner, Inoue-san, a very knowledgeable man who, besides selling tools to professionals and hobbyists, teaches woodworking at a nearby high school.
Before this visit, I purchased my woodworking tools online, so seeing and holding the tools like this was eye-opening. I told Inoue-san I was looking for a smaller plane and a dovetailing chisel, and over a cup of coffee he explained which tools would suit me based on my needs and my budget. After I settled on the plane and chisel that I wanted, Inoue-san asked if I was in a hurry to leave (I wasn’t). He smiled and asked his wife to fetch him a pail of water. He led me to his sharpening station, took out a flat piece of iron plate (kanna-ba), sprinkled some baby (talcum) powder onto the plate, and added a few drops of water from the pail to form a paste. Inoue-san then started to lap the back of my newly purchased plane blade. I had never seen such a process before, and I paid very close attention to what he was doing. The lapping was done in a controlled motion with light strokes.
After each burst of lapping, Inoue-san would turn the blade over to inspect it for even flatness. The super-fine abrasive paste polished the back, revealing high spots. After his initial flatness inspection, the back of the blade showed a highly polished strip all the way across, except for one of the corners. I expected Inoue-san to bring out a coarse stone and start lapping away to remove more material; instead, he took out an anvil made of soft wrought iron and reached for his hammer. “Uradashi!” he said. All of a sudden, I understood why uradashi would be more efficient than removing material. Because of the laminated construction of the blade, tapping the soft iron on the bottom of the bevel creates an impact that pushes out the hard steel. The soft anvil provided good support for the blade and absorbed the hammer blows. Inoue-san alternated between the kanna-ba and anvil several times before the back was entirely flat. He then showed me proper freehand sharpening techniques on both synthetic and natural stones.
–Kim Choy, excerpt from “10,000 Hours: A Journey into Japanese Woodworking,” in Issue Five