The process of repair and bringing back the old glory of old Japanese blades requires more skill and knowledge and should not be attempted on your own. It is certainly possible to do a decent and acceptable initial polish job on a blade with the aid of non-traditional materials and techniques, nevertheless a trained polisher must be consulted.

Some modern smiths employ the use of sandpaper and small stones for newly made blades where the major shaping has been done on the grinder (i.e. the blade is ground to nearly perfect shape before “polishing”). In this case, sandpaper or small stones can be used for progressively removing scratches from the pre-shaped blade.

It is a different case for old blades or even blades where there is damage to be repaired such as those showing chips, rust, among others. If that is the case, some degree of reshaping is needed since it’s difficult to tell how many times a blade has been polished previously, even for a new blade, re-grinding the foundation using a power tool is a risky prospect. It is just not possible for older blades where you might only be a few strokes away from exposing the soft core steel.

Restoration and repairs can only properly be done using traditional techniques. For old samurai blades in particular, a trained polisher is the only option you have to salvage the blade.

You must consider the following things when repairing damage on a blade. For example, whether or not to change the convexity or “niku” of the edge, whether to move the “shinogi” (ridge, line) evenly over the entire edge, or to taper it towards the point to maintain visual balance, whether to shift the position of the “yokote” line (tip separation line) and reshape the point, etc.

Some of these things will be at odds with trying to preserve the intentions of the smith and school. More often than not, an improper decision can greatly reduce the value of an samurai sword to merely nothing. A polisher must have the knowledge to decide where to maintain and where to repair. For example, a characteristic of Yamato school is the very high shinogi ridge giving the blade a very pronounced diamond shape. When restoring such a blade, in order to maintain and for the blade to be recognized as a Yamato school blade, then the pronounced diamond cross section must be preserved, even if you have to leave something else unfixed. It is very important that some of these features are identifying characteristics of specific schools and smiths. The rationale of such importance of the diamond cross section is best explained in this scenario: for example you had a sword signed “Masamune”, and the signature was correct, but an unskilled polisher messed up the shape or practically altered the shape, the appraiser or any knowledgeable buyer would say that this sword does not have the characteristics of a real Masamune blade, and so the signature must be a fake. In the end, instead of having a sword worth a $1,000,000 you now have a sword maybe worth less than $1,000!

To protect the value of the samurai sword, everything has to match up. The signature must be right and the workmanship must reflect its smith. Any small deviation could result in the sword being declared a fake sword. Now, obviously, this importance does not apply with a blade you’ve purchased for cutting practice, etc. But in this case, proper restoration is still vital even if the sword is used with proper care which should last up to several hundred years, but indiscrimate use of abrasives even chemical abrasives like MetalGlo and Flitz does not only harm the weapon’s functional potential but also severely shorten its lifespan.

Technorati Tags: old blades, old japanese blades, polishing, samurai weapons