Continuing... GRINDING!
Guys, sorry for any language mystakes. I don't speak english, but I have been study every day, and have been make vip classes. Sorry for eventual wrongs! I'm enforcing me!!!
In this post I bring my method of machining a traditional Japanese kitchen knife, the model is called Santoku.
Traditionally Japanese bladesmiths not produce integral knives. Substantially all of the knife models of Japanese School is mounted.
As the full construction is a strong characteristic of Brazilian Bladesmiths, virtually all kitchen knives that I produce, are integral. So I adapted my way to work the Japanese model.
Following demonstrate my step by step machining.
The first step of grinding forged damascus knives with dies or forged damascus knives manually, is the removal of the "carepa" just we called in Brazil.
The resulting iron oxide heating. One of russets characteristics is that it is extremely hard, which consequently destroys very quickly sanding belts. Thus, whatever the forging method of the knife, I recommend complete removal of iron oxide (I don't this name in English! Tell me please!), on all sides of the knife. When grinding, take great care with the disc tilt with relative to the blade. If too lean, you can in a split second, producing a groove in the blade, which may order the part. Be especially careful with the back and the edge region, as by being edges they are much easier to produce an accidental groove.
The blade carefully grinded!
The first step to do the grinding the knife, whatever model is define the profile. For this, invariably, the back of the blade, that in almost all models, is a reference to the grinding of the other parties. The exception with respect to start the back, are daggers and double-edged swords, which obviously has no back. Today do not like to pre-design a model,
nor to work attached to the X or Y inches, with the caliper at hand. I did so many years at the beginning of his career and to recommend new bladesmiths. But today, with years of practice and studying constantly models and proportions rather trust the eyes, that trained and adjust the proportions of the best. I always ask customer to trust in my ability to fabricate the knife, it is common that the measures it passed, do not result in the best proportions, which will result in a beautiful knife and high performance in use.
Looks like the cap protects my eyes from sparks! It's very important secutity equipment too!
After the profile, always grind the sides of the blade. Remembering that my constructive method always makes flat convex design. Another method also much used is called hollow ground, but I do not use this. For those who are starting, will advice:
From the beginning accustom yourself to use both hands for to grind the knife. This will preserve his "good arm" of overuse. Fortunately I developed this ability from the start and I am ambidextrous to machine. I know that in the early development of skills that will be difficult, but persists worth. A memory:
Nearly 100% of the sides of the blade grinding, is performed with the edge facing upward. Exceptions precisely this type of integral construction, where for a few moments, grinding with the edge down. About grinding standing or sitting, I think everyone should do the way you feel more comfortable and safe.
Just one more tip: As in the picture, position yourself with the eyes of upright grinding machine to take full control of the blade contact angles on the sanding belt.
For this model specifically I decided to do the integral bolster, grinded at 90°. Most of my bolsters are grinding on the roller, ending the blade symmetric and harmonious curves, which I think is more beautiful. The characteristics of the traditional Japanese style, decided by 90 degrees. For this grinding the sides of the bolster so as to be parallel one with respect to another and both with respect to the center line of the back. Then hold the blade in the file guild and grinding the side manually by file. It's easy to do.
The next step is the printing of the mark on the side of the blade. I always use a pen to scratch the region, parallel to the back of the blade. I do not recommend you to do the alignment in the eye. Already I missed doing this way and marked the inclined blade.
To position the blade to be printed, make a simple support, like the photo and use shims at the opposite end, in order to regulate the inclination. The secret is to keep the top of the stamp parallel, both the north / south axis, as in the east / west, with respect to the press cylinder support. I often also regulate the support tilt the base of the press, on which the knife is by placing taps the thin end, so as to leave the aforementioned parallel surfaces. For this printing style, a press of 15 tons is sufficient. My stamp has very thick and blunt surface and I can stamp with 11 tons of pressure.
Stamped blade. One point that I would like to highlight relevant and is unnecessary sanding the blade, with manual or belt sanders, the finer the grain 50 prior to heat treatment. I did it for many years in the career start. Grinding the sander to the grain 220 and the hand to the 320. After he tempered and remade almost everything. I learned this way and I answered for some time. Not necessary! Grain 50, after quenching, then yes makes it the ultimate finish!
Very nice work, your english is good, by the way.