Process of the Polishing Work

The sword restoring work is roughly divided two steps. The first is shaping, next is polishing. These two steps are very different on their action. And the shaping is the most important for the blade, and most difficult in the polishing work.
1) shaping To restore the blade we shape it with stones. We start with a rough stone, and step up toward finer one to make the shape finer. Normally we use some kinds of stones, from rough to fine, Arato, Binsui, Kaisei, Chu-Nagura, Koma-Nagura, and Uchigumori. For this work, the shape of the stone is very important.Wide stone is good for the flat surface and the cutting surface. Narrow one is good for the back surface. Stones, there are two kinds, natural stone and artificial one. Each kind has good point.
preparation Before starting the shaping work, we have to study the blade exactly to make a plan how shape it up. And straighten the blade with wood vice. To make it exactly is very important to get good shape.
ARATO stone The most rough stone. We use it only for fresh borne blade or deep rusted one, to make a good shape. Hold the blade with right angle to the stone, and push the arms forward. For the flat surface (shinogiji), a little slant angle is not so bad. For the back surface, hold the blade 45 degrees to the stone, and push forward. The work is same to the next step BINSUI. This step is the most important for the shaping. The system is very simple but it is the most difficult in all steps of shaping. Never grind too much steel. We have to get the perfect shape with the least grinding.BINSUI stone Most of blades are started with this stone. To remove rust and make a good shape. Be careful to save the flesh on the cutting surface.KAISEI stone To make the shape finer. Hold the blade with 45 degrees to the stone, and push the arms forward. But the working system for kissaki never change with any stones.CHU-NAGURA stone To make the shape finer. From this step we never use artificial stones. ( In some case artificial stones are easy to be used by hobby polishers. ) Hold the blade 45 degrees to the stone, and move the blade along the blade's length. The work looks like pushing the blade toward the left hand. The trace should be parallel to the length or a little slant.KOMA-NAGURA stone To make the shape finer. This stone is a little finer and harder than CHU-NAGURA stone. The work is same to CHU-NAGURA step. But the trace has to be very parallel to the length. UCHIGUMORI stone To complete the shape and to make the character of the blade come up. Hold the blade the same way as in the previous step. But the working direction is opposite. It is pulling the blade carefully towards your right hand. Then every surface is completely shaped, and the characters come up.
2) polishing To study the quality of the blade we make the surfaces clear. Then we can see the details easily. In the polishing work, there are two kinds of finishing style. One is the classical polishing style (SASHIKOMI). The other is the modern polishing style (HADORI). The big different between them is in the step of NUGUI.
preparation Before starting the polishing work, we have to make the stuff for the work, HAZUYA, JIZUYA and NUGUI. Good preparation is very important for smooth work. making hazuya and jizuya Hazuya is made from uchigumori stone. Jizuya is from narutaki stone. Both stones are similar kinds of finest stone in Japan. Narutaki is a little harder than Uchigumori. The fineness of texture and the hardness is very important to select them. Slice the stone with chisel and hammer.Grind them to get flat surface and the thickness as thin as paper.Fix them on the paper with lacquer. The paper should be thin and strong. Cut and shape them to proper size. Grind them again to the proper thickness to use. The hazuya for NARUME work is larger size and the best quality. making nugui powder Nugui is very fine powder mixed with oil. Each polishers have their own powder making system and material. One of them is grind the material completely with mortar to the finest powder. Examples of the materials are, narutaki stone, tsushima stone, iron ore, oxidized iron, and other things. polishing migaki needles There are some kind of needles with different shapes for blades' surfaces. Polish them up completely to get mirror surface on its own. The finish of needle surface moves to blade surface. HAZUYA HAZUYA is a very thin Uchigumori stone fixed on the paper.Polish the blade surface with HAZUYA on the thumb completely, especially in the hamon.Then the surface becomes clean. And all the tempering effects come to be seen.JIZUYA JIZUYA is a very thin NARUTAKI stone. Some of them are fixed with paper, and some are not. Choice is case by case. And select suitable quality jizuya for the steel quality. Polish the blade surface with JIZUYA completely except the hamon area. The steel becomes clear and the steel particles come up.NUGUI NUGUI is a very fine stone powder mixed with oil. Polish the whole surface of the blade with it using cotton ball. In this step, the work is very different between the classical style and the modern style. The nugui work in the classical style is the final cleaning for the blade surface. The work in the modern style is to make up a good contrast for an attractive view. On the classical style, natural stones can be used for NUGUI. There are various kinds of stone for it, for example, NARUTAKI, NAGURA, TSUSHIMA, iron ore.The surface becomes clean and the hamon comes up.On the modern style, polishers have their own special material and oil for nugui. It is far harder than the classical style's to make a black shining surface on the blade. The work effects whole surface of the blade even on the hamon. So the hamon is masked by this hard effective polishing. Then the hamon area has to be polished again with hazuya. Polisher uses hazuya carefully by their thumb to make a white pattern along the hamon. This work is called "HADORI". So this polishing style is called " HADORI style". Good hadori work makes good contrast between the white pattern and the rest black shining area. On this work polishers are thinking to get an attractive view. So the pattern of white area is quite different by each polisher's sense, even if the hamon would be the same. And the real hamon can be seen in the white pattern when you use good lighting.
Be careful, some polishers use acids or chemical treatment on polishing process to trick the view. They emphasize hamon pattern and layer pattern, and its view is indecent and unnatural. However skilful it is, they never lift the blade quality up, only damage the steel. Such work is done for purpose to deceive beginners. It is very bad for serious sword lovers. Good polishing never use any acid.