Hamon Depth

[Thekirsh]

I was just wondering when you look at the condition of a blade is there a minimum depth that the hamon can be before it is judged to be over polished?

I have read of the core metal showing or the blade becoming to thin but not much about the hamon.

Simon

[Carlo Giuseppe Tacchini]

I've seen a Rai school Tanto with less then a millimeter Ha left

in some points, but still considered alive. No exposed Shingane and

likely no other polishing allowed. It needs some prayers...

[nagamaki - Franco]

When the depth of the hamachi and boshi are at risk of running off, unless a blade is of some importance as in Carlo's example, then most blades begin to fall into that "over polished" category.

Its best to ask a polisher as its amazing what they can do at times with saving blades.

 

fd

[Brian]

If you are talking about the width of the hamon, then unless it does run off anywhere..it is not considered fatal yet. If a subsequent polish will allow it to run off, then that will be taken into account before professional polishing.

Some schools (such as some Naminohira blades) specialised in a thin suguha hamon called ito suguha..so a thin hamon is not necessarily a sign of an over polished blade. The condition of the machi and the characteristics of the school would need to be taken into account before declaring the blade over polished.

 

Brian

[Carlo Giuseppe Tacchini]

Brian is right. Machiokuri is possible but not ever, so maybe you find to have enough Ha (in case of very broad ones) left, but no room for a new machi without altering too much the Nakago.

[David Flynn]

I have seen some Hein blades, where the Hamon is only 1 mm or two thick, and the boshi is gone. These were still classed as acceptable and I am lead to believe, some like this have made juyo.

[kusunokimasahige]

but when is a blade considered "ruined" by overpolishing?

 

when all core steel is visible? when the Hamon is totally gone?

 

does anyone of you have Photos of ruined swords?

 

would be nice to see a visual reference!

 

KM

[John A Stuart]

Hi, This is a point where opinions abound. So these are my thoughts. To the collector of nihonto for its artistic merit a blade would be unacceptable when the wear overwhelms the artfulness of the sword. Certain swords of immense provenance would be viewed with a less critical eye. Collectors with a more historical bent would see a value that relates to the study of a sword to ascertain certain data or fill a smith or period niche. With this in mind I am sure most judges would think in a similar way. A sword newly discovered by a smith known to have existed but never had an example extant, even though 'ruined by general standards' would still be an immensely valued object. John

[mike yeon]

A simple way to look at it is asking "is the sword functional?" We should remember that Japanese smiths for the most part made their blades with the full intention of creating a weapon, not a piece of art. What we as collectors find artistic today (hamon/hada/shape) were seen as utilitarian or adhering to tradition by the old smiths.

 

If the hamon falls off the edge in any way, it is considered flatally flawed because it cannot hold an edge in these spots. The integrity of the yakiba is diminished (creating stress points). Like John mentioned there's a lot of ways to look at it. But if you want to be strict, none of the Japanese organizations will paper a blade with a broken yakiba. (unless as John also pointed out, it's a rare case of a very important blade).

 

mike

[kusunokimasahige]

So is re-hamonning possible at all??

 

is that done? can it at all be done? or is that in the realm of retempering...

 

is it possible to reheat a blade re-covered in clay, to get a new Hamon?

 

just a question....... very interested in the technical aspect!

 

KM

[John A Stuart]

Hi KM, It is done quite often and is termed sai ha. The telltale is mizukage among others. There was discussion once where it was mentioned that there is a fairly high percentage of sai ha blades floating around including highly regarded examples of rehardened and tempered blades of prominent smiths that had been caught in fire and repaired by other prominent smiths. John

[kusunokimasahige]

I found this site:

 

http://www.ksky.ne.jp/~sumie99/index.html

 

on which they state that it is not always a sign of retempering...

 

however i find what you write very interesting!

 

anyone ever retempered their nihon-to or had it retempered?

 

KM

[mike yeon]

KM, retempering is looked at as a flaw. We don't retemper blades today because we don't use them (in very few cases retempering is done to try and save an old masterpiece).

 

In the past people retempered blades because it was expensive to buy new swords. Retempering effectively returns a hard edge to the blade so it can still be useable. In the proccess, it loses the original characteristics including many activities in the hamon. Retempered blades I've seen had wide/cloudy suguha hamons. The shape also changes dramatically and there will be un-natural curves in even the best retemper jobs.

 

mike

[Curran]

Hamon:

 

Ultimately, it is your call. On pre-1500s stuff, if it runs near or touches the edge, but is of true artistic merit... very few Japanese seem to mind. Even if it looks like it is at the very edge of the blade in a few spots, a good polisher can still do wonders.

 

I have seen many a thin to microscope thin hamon on many a nice old Yamato, Yamashiro, and Bizen piece.

 

I have seen Juyo and even a Toku Juyo with small areas (1.5 inches or less) of what I would call 'no hamon'. I don't fully understand it, as some of the blades' artistic appeal escaped me.

 

Then, one of the nicest blades I have ever had the chance to study for a while was a nice Bizen blade where the hamon got very thin in one or two small spots. It bothered me for the first few days I got to look at, but the more I studied and held it and considered it both as art & a weapon; I thought it had lost nothing and was one of the most elegantly balanced (in art and function) Nihonto I'd gotten to study. Those fingernail wide areas thin hamon points were quickly eclipsed in my mind.

 

Retemper:

 

Extremely complex issue. Mizu-kage on both sides of the blade with loss of activity is a sign of the retemper have spoken about.

 

But there are other signs that some call retemper. The one I most often mention is when something (usually pre-Edo blades that were probably used in the warring states period) and had the hamachi moved up- it has been shown to me how it was often done with a heated copper block to soften the metal structure in the edge and not split/hagire when cutting the new hamachi. Creates a bit of what looks like mizukage on one side, but doesn't seem to have much other affect on the blade. I DO NOT consider this a retemper.

I've seen dealers claim these blades are 'retempers' to get a seller down, then try and buy and paper them. I'm thinking of a nice Bizen blade where the owner decided not to believe one of our self proclaimed "foremost experts"- and it papered very well. Absolutely beautiful blade.

 

The sort of retemper you mention is very hard to do well. It leaves lots of clues, and if those clues are inconsistent with the school from which the blade originates- then you do (highly likely) have a retemper different from its original form and now mostly a weapon- not so much a piece of original form artwork.

 

But then sometimes these clues are misleading. I know of 4 blades, all Oei period Bizen or Yamashiro-Bizen that were called retempers by many experts because of "the clues". All of these 4 blades (2 swords and 2 O-tanto) now have Tokubetsu Hozon papers. One of the O-tanto belongs to me. That one won't leave me until I am in my coffin.

 

But yes, a true retemper puts a lot of stress on a blade already under stress. It changes the shape and creates havoc in some areas leaving 'clues'- especially along the mune in those I've been able to study.

 

The retemper issue can be a very complex one.