Once the forging of the blade has been completed and the swordsmith has given the sword a rough polish (kaji-togi) it is then passed to a professional sword polisher. The polisher’s job is very important to the aesthetic and function of a Japanese sword.
Japanese sword polishers do not only polish new swords, it is also their job to restore and preserve old blades too. As one would expect, in order to preserve an old blade you would not want to have it polished very often, in fact as little as possible, for very time a blade is polished a small amount of steel is removed. However, it is much easier to care for and preserve a blade that is in good polish and in a good shirasaya (sleeping scabbard) than one in poor condition and is already rusting.
In broad terms sword polishing is broken into two-parts: foundation work (shitaji-togi) and finishing work (shiage-togi). This division can be discerned by the posture used by the polisher to carry out that particular part of the polishing process.
Shitaji-togi (foundation work)
Omura-to, Aoto, Iyoto, Binsui, Kaisei, Nagura, Komanagura,
When foundation polishing is being performed the polisher sits in a crouched position and moves the blade across large polishing stones. From which stone that the polishing process begins depends on the age and condition of a blade in question. For instance, new blades would usually begin from the coarsest stones whereas old blades may start from a bit further along in the process so as not to remove too much steel. There is an old adage amongst polishers that says “You can always take more steel off, but you can’t put it back on”.
In the case of new or very rusty blades the process may begin from the coarsest stones. This first half of the foundation polishing process is for removing any deep rust and perfecting or repairing the shape (sugata) of the blade. In the second half of the foundation process gradually finer and finer graded stones are used in order to remove the scratches caused by the coarse stones.
Shiage-togi (finishing work)
Hazuya, Jizuya, Nugui, Hadori, Narume, Migaki (burnishing)
In the case of shiage-togi the polisher will sit in an upright position resting the blade on his leg or a pedestal and polish it using stone wafers on the end of his thumb. This is always performed from the mune (back of the blade) so as to reduce the possibility of cutting oneself. Only in the case of a hadori finish (cosmetic polish applied to the hamon), is polishing performed from the cutting edge. In the next stage a compound of iron oxide mixed with choji-oil called nugui is applied to the blade. Depending on whether a Sashikomi polish or a hadori polish is being applied depends on which kind of nugui is applied. This compound revitalises the steel somewhat after the constant abrasion by the stones. It also darkens the color of the steel, after which the hadori polish may be applied in order to highlight the hamon. This is the burnishing process applied to the shinogi-ji and the mune. To do this tungsten burnishing rods are used. This is the very last stage of the polishing process. *Editor’s note. This brief explanation of Japanese sword polishing is in no way shape or form a guide to polishing Japanese swords. It is only an explanation of the Japanese sword polishing process, the training required and the complexities of the profession. Please do not attempt to polish any blades yourself, but send them to a professional Japanese polisher who has completed a full apprenticeship under a recognised artisan. If you would like help in contacting a professional Japanese sword polisher please feel free to contact us via our contact page.