Yari Ganna (Yarri Kanna) - the ancient type of Japanese Plane
Drawing the blade of the Yarri-Kanna across the work should result in fine shavings, given a very sharp blade and proper positioning of the tool. Inexperienced users tend to hold the tool at too sharp of an angle to the work, which causes the blade to dig in. The blade should be held at the shallowest angle possible to the surface of the work, almost horizontally, and should also be drawn across the work at a trailing angle, almost "gliding" over the surface. The Yarri-Kanna should not be used as a drill, and only light pressure should be exerted on the tool when "planing" (shaving). Otherwise, due to its shape and hardness, the blade may break, for which we naturally cannot be responsible.
Sharpening the Yarri Kanna is less complicated than it may look. If you can hand-sharpen plane blades and knives, you should be able to make the transition to sharpening the Yarri Kana in a very short time. The cross-section of the blade is simply a triangle, consisting of two bevels and the polished face. The face is concave, similar to that of a Japanes chisel. To sharpen the bevels, use a small contoured stone (as found with the Japanese waterstones in our woodcarving set). Clamp the handle of the tool in a vise, face downward, blade resting on a workbench or other surface, placing the bevel free so that the stone can be freely drawn over it. Working the bevels with the stone will create burrs on both sides of the face. These may be removed by moving the tool's face back and forth over a flat stone with a rocking motion.
It is obviously more dangerous to draw a sharpening stone over a blade than it is to draw the blade over a stone, and proper care must be taken when sharpening. Carelessness when working with the small slip-form stones can very easily result in a cut.
Caution must be exercised not only in sharpening but also in using the Yarri-Kana to minimize the risk of cuts.
Take your time and concentrate when sharpening!