How Many Polishes In A Lifetime?

[general_piffle]

This thought popped into my head today and I appreciate it's a bit of a 'piece of string' question because there are many variables. For example, thickness/size of a katana to start with and variations in different styles and approaches by different polishers. But I wanted to find out more about polishing as part of a katana's life.

 

Roughly how many polishes would a katana undergo until it was better to 'leave as is'? Why/when would a katana typically be polished? How much material might be removed in a typical polish that doesn't include any repair work? Any other interesting notes or insights around polishing?

 

For the queries above I'm assuming the polisher is traditionally trained and knows what they're doing. Not some butcher with a belt sander!

 

Thanks in advance for your thoughts.

 

[Ray Singer]

Hi Joel,

 

    The number a polish a sword can sustain varies dramatically according to its construction (for example, how close the shingane is to the surface), whether it has sustained damage (removing deep rust or hakobore can greatly reduce a sword in a single polish), the presence of kizu (and their location) and other factors. Sometimes swords have been preserved with very few polishes over their lifetimes. Daimyo treasure swords for example may have been maintained in close to their original condition. As one example, you can see this in the sword collection of the Uesugi family where most have been kept ubu, in their original koshirae and in like-new condition. You can also sometimes find swords like this in the "wild" and it is easy to mistake them for much later swords. The Korekazu I sold here was incredible healthy and Andrew Ickeringill later commented that he felt it only had 1-2 polishes since it's original. I have a Nobukuni which is like this as well, with a 8.5mm kasane that is close to its original state.

 

Kind regards,

Ray

[Geraint]

Dear Joel.

 

You are absolutely correct about the piece of string idea but here are some thoughts.  I have heard it said that a polish will last 100 years but this is surely arbitrary.  Degree of use, conditions of storage, original construction and a number of other factors play a part.  A tachi in the collection of a daimyo which never sees the light of day might do very well whereas a tachi that has been carried in battle and worn by a succession of owners will inevitable require more care and attention.  I once handled a Nambokucho tachi which gave every impression of being Shinshinto because it was in such health, it cannot have seen very many polishes at all.  The other side of this coin is that a meaty blade might take several polishes without showing signs of age whereas a thinner blade might start to become very light after only a few.

 

The construction of the sword also plays a part here, Hizen-to are notorious for their thin skin steel and are likely to reveal core metal after a very few polishes, a sword constructed in a different way might take considerably more polishes before displaying signs of tiredness.  You rule out damage but that in itself is not an easy thing to quantify, how about light rust?  Talking with polishers it seems that what appears to be very light and hence shallow rust sometimes has a way of masking pitting that requires the removal of more metal.

 

If you are interested in the effects of polishing on blades then I recommend Nakahara's Facts and Fundamentals which includes some valuable insights into the effects of such work over the life of a sword.

 

Random thoughts, make of them what you can.

 

(Crossed posts with Ray but at least there is some commonality in what we are saying)>

.

 

All the best.

[nagamaki - Franco]

Additionally,

 

1. Some of the earlier swords were made without core steel and can become surprisingly thin without showing folding related flaws in the steel. There would be other things to worry about, but otherwise should be ok even after a good number of polishes..

 

2. One polisher commented, when shown, that he thought a late nambokucho period sword still had at least a half a dozen more polishes left in it.

 

Yuh, depends on the sword, depends on any previous physical damage. 

[SAS]

Once the steel has been taken off, it can't be put back; therefore, a polisher uses his judgement to determine whether certain blemishes should be left in the interest of preservation of the sword. 

[general_piffle]

Thank you all for your insights. Much appreciated.