Gassan Sadakatsu and Masamune's secret process

[DoTanuki yokai]

11 hours ago, Apercus said:

Twisting the sunobe does not produce ayasugi hada. It’s usually created by cutting, filing, or grinding groves in both sides of an oversized bar while alternating the locations between sides. The groves would be deepest at the edge and more shallow towards the mune. The bar would then be forged flat into the sunobe. It’s a common technique used be knife makers today. Twisting a bar produces a very different effect that looks nothing like ayasugi hada.

 

I don’t know how the Gassan in Muromachi (and today) made the Ayasugi Hada but I’m very sure they did not cut into the sunobe like it is done in ladder “Damascus” for some reasons. 
It would be very time consuming to do without electric tools and a waste of expensive material.

I can think of ways to do it in the forging process but don’t know really. 

[Apercus]

You may be right. There are other ways to produce it that are less wasteful and difficult. It’s just not produced by twisting the bar.

Edited May 19, 2023 by Apercus
Typo

[Bryce]

G'day Guys,

Here is a shot of the boshi.

Cheers,

Bryce

 

[Bryce]

G'day Guys,

I realise now that when Gassan Sadakatsu is referring to a blade as Soshu den or Bizen den he is only referring to the hamon style rather than the hada. Thus you see blades described by him as Soshu den with hada ranging from "standing out" itame, thru to pure masame and even very tight koitame. Here is the hamon from the 1938 boxed gunto example posted above.

Cheers,

Bryce

 

[Bryce]

G'day Guys,

A Japanese dealer made the comment that he thought one of these blades by Sadakatsu resembled the Ishida Masamune sword. After tracking down a description of this blade on the internet I have to agree. Sadakatsu's Showa era blades closely match this sword, both in sugata, hada and hamon.

 

e-Museum - Sword with no sign, by Masamune (celebrated Ishida Masamune) (nich.go.jp)

 

Cheers,

Bryce

 

[Bryce]

G'day Guys,

I think that Japanese dealer was spot on. I think the Ishida Masamune had a massive influence on Gassan Sadakatsu. The earliest mention I have come across of Soshu Masamune Den on a Gassan blade was the blade that started this thread. It is a Sadakazu daisaku by Sadakatsu dated Meiji 30 (1897). What I first noticed about this blade is that it is a dead ringer for Sadakatsu's usual Showa period blades. The sugata is very different to the usual Gassan blades being produced up to this point, but almost identical to the Ishida Masamune. I don't think that can be a coincidence? Here is a comparison photo of the Ishida Masamune (top) and the blade signed Sadakazu Meiji 30 (below).

Cheers,

Bryce

 

[Rivkin]

Below: Sadakatsu versus Masamune, I did not process either image to the fullest yet.

As with most shinshinto and especially gendai which carries some study of Ikkansai Yoshihiro's approach - Sadakatsu's "Masamune" will have only small nie which does not sparkle too much and all forging lines are going to be pristine and well defined.

Masamune will have at least two fukure, everything will be three notches brighter, nie size will be all over the board, transitions much more natural and irregular.

[Bryce]

G'day Kirill,

Thank you for that comparison. I agree that generally a Gassan Sadakatsu will exhibit uniform ko-nie and clean, well defined forging lines. Below is a comparison of a Gassan Sadakatsu in my collection done in masame on the right, with the Masamune photo you supplied on the left. It would be nice to be able to compare them in the same light.

Cheers,

Bryce