Micro chips

[jezah81]

After just recently cutting a few bamboo poles, i just checked the edge of my shinsakuto under the light, and i can see some really really small chips along the edge in the monouchi part. Surprisingly, it still cuts through paper like a razor, and feels sharp as hell when you touch it. So, is it anything i should worry about, can i keep cutting with the blade??

Kind Regards,

[ichibyoshi]

Is cutting paper a good idea? I know my mum always used to freak out if I used her "good" fabric scissors to cut paper. She always said it would blunt them. Now I have no idea how this is so, but that's the power of a mother's rules: 35 years later, I still think they must mean something!

b

[kdlarman]

Well, to say what should be perfectly obvious, the bamboo is chipping your blade. Continue doing it and you will chip it further. Continue further and you could permanently and irrevocably damage the blade.

[Ken-Hawaii]

Keith, that's a very interesting statement.

I've been cutting bamboo ranging from 1-2.5 inches in diameter for quite awhile now (two years-plus), & I see absolutely no effect whatsoever on my shinken, even under magnification. Why would there be such a difference :confused:??

I'm using a hand-forged 1095 blade, clay-tempered with a hybrid polish. Nothing special about it that I know of. The sharpness & cuting ability doesn't appear to be affected during tameshigiri with tatami omote, either.

Could you please elaborate? Thanks!

[renfield_kuroda]

Not to overstate the obvious, but since all swords and bamboo are different, it's tough to use one's experience in judging another's.
I would say you've got some combination of hard bamboo and brittle shinken -- not that there may be anything wrong with the sword, per se.
But the brittler the steel, the more likely to chip. Perhaps it was oversharpened? Perhaps it's stressed to the point of critical failure? Perhaps your bamboo is too dry and tough?
Impossible to tell from here.
Be safe.

Regards,

r e n

[JAnstey]

Is cutting paper a good idea? I know my mum always used to freak out if I used her "good" fabric scissors to cut paper. She always said it would blunt them. Now I have no idea how this is so, but that's the power of a mother's rules: 35 years later, I still think they must mean something!

b

Ben you are 100% correct paper contains kaolin which is a white clay like material, basically is is a sedimentary rock. Paper also contains other oxides and in most cases acids, however Kaolin is the main enemy.

Listen to you mum! :p

Cheers

Jason

[jezah81]

Hi guys,

Thanks for all the useful information. I just got in contact with my friend in Japan who cuts VERY regularly. He has a Showa blade which is 80 years old, in original polish, it also has micro chips and cuts like anything until now. In response to the micro chips he told me " that was the nature of cutting".He also knows many other people in Japan(in the battodo circle) who use cheap shinsakuto (under $10,000AUD) for cutting bamboo, tatami etc.... Also knows alot of people who cut with Showa blades. Many people in Japan also sharpen their own shinsakuto using the hazuya stone. Ive heard Toshishiro Obata and Sekiguchi-soke Sensei also advocate this. There are some people who also use shinsakuto that havent had the last stage of polishing done on it. The blade is just dull, grey and shows no sign of a hamon or jihada. So, from what i have surmised, i think there may be nothing to really worry about. At the end of the day, cheap shinsakuto are just a modern day blade, a workhorse and they are replaceable.

Kind Regards,