Thread: Kagi-ba-Sword forging shop

So much to comment on. Good motivation on the shop man, coming along. I could use just a tad more (motivation) for keeping my own in better state of cleanliness.

State of American craftsmanship; probably not as bad as you think, look at the customs displayed here! There seems to be a resurgence in skilled trades in this country. People are starting to remember that working with ones hands in general and creating new or new from old is a noble task. At one time men who created were highly regarded, I hope that time is to return.

Collecting; It's OK, lets face it guys some of what we make is art, plain and simple. I prefer to use an item for its intended purpose, and when I build new, I build to be used and abused. I drove my 701/2 Camero RS all the time (mid 90s). Many people told me I should take it off the road, UMMMM wait... that was mostly the police...

Jeff

It may be art, but it is art intended to be used.
I will not make a razor or knife for someone who does not intend to use it, and I have never restored a razor for someone who would not care for it afterwards. I don't spend all that time to make or restore it, only to have it never used or neglected.

Originally Posted by Bruno

Ok to get back to the swords: how is it that a skilled user can make a thousand successive tameshigiri cuts with the same blade? If a blade gets unusable after 3 cuts, what is then the significant difference with tameshigiri?

This could get really esoteric but keeping to the physical, cutting thru a rib cage & spinal column may well cause more damage than cutting wet mats ? I think back in the day the reality of armoured battle would see a lot stabbing of unprotected targets where the armour hinged. A sharp edge is unnecessary then.

Bruno, I have had occasion to help in surgery. Now you'd think that a surgeon would have access to the best modern steel for a scalpel. The people that make scalpels believe they produce a fine scalpel and work to refine the stainless steels they use. But a sharp edge on a scalpel is crap after about 24 inches of cutting skin, sometimes even less. A human beings innards are acidic very slightly. Just enough to erode a fine edge. Plus, the gore will stick to even the finest polished surface. That creates drag. The blade is likely still "good" but it's no longer efficient. Cutting straw doesn't produce gore and doesn't erode the edge as actively as meat.

"Wet" bone cuts surprisingly well if the technique is good. As an example, try cutting growing bamboo and then cut some dry bamboo of the same diameter. For the most part, good technique will trump the quality of a blade every time.

I apologize for helping this conversation, um, wander. A bit.

Originally Posted by Mike Blue

Bruno, I have had occasion to help in surgery. Now you'd think that a surgeon would have access to the best modern steel for a scalpel. The people that make scalpels believe they produce a fine scalpel and work to refine the stainless steels they use. But a sharp edge on a scalpel is crap after about 24 inches of cutting skin, sometimes even less. A human beings innards are acidic very slightly. Just enough to erode a fine edge. Plus, the gore will stick to even the finest polished surface. That creates drag. The blade is likely still "good" but it's no longer efficient. Cutting straw doesn't produce gore and doesn't erode the edge as actively as meat.

"Wet" bone cuts surprisingly well if the technique is good. As an example, try cutting growing bamboo and then cut some dry bamboo of the same diameter. For the most part, good technique will trump the quality of a blade every time.

I apologize for helping this conversation, um, wander. A bit.

Actually I like the way this conversation has wandered.

Mike,
I saw a story one time of someone making scalpels out of obsidian. Have you any experience with these and do they resist the corrosive effects of the human body any better than stainless?

Your good technique comment is true. I watched a show just last night "Penn and Teller tell a a lie." They shot at a katana in a rigid setup and it split the bullet. But then they set up a plain old butter knife and shot at it as well. It split the bullet as well. Now the katana split it cleanly and the butter knife kind of shattered it into more than two pieces. Point is, it was the speed of the bullet doing most of the work.

As a side note, it is the same with a sword cut. It is the velocity of the blade, not the power put behind it that makes it effective.
Speed + mass =energy.
That is why the technique of the cut is far more important then the power of the cut.

As far as the user/collector debate I say thank God for collectors. Without them the remarkably unique craft of the Japanese sword would have probably been lost after WWII. There would have no custom knife industry that began with Bob Loveless and a few others in the 70s. A razor can be used but there is little or no practical, legal use for a Katana or a long, pointy, double edge, stab somebody in the heart thingy.

If somebody wants to buy something from me in order have the pleasure of looking at it and holding it I am more than OK with that. Having said that I agree that I get more personal satisfaction from someone using one of my tools on a regular basis.

Originally Posted by Danocon

Speed + mass =energy.
That is why the technique of the cut is far more important then the power of the cut.

actually, energy = m * velocity^2
except we have to consider the fact that this is a rotating object so the angular momentum counts as well.


Now, I know swords are not used anymore for cutting people in half, but aren't most genuine shinken used for JMA practice?

Great thread. Angular momentum at a constant speed is acceleration IIRC.

No disrespect meant Bruno, but if I can build something that some guy wants to display I get to charge him more for it and can make more of the daily tool for use for at more reasonable cost. And after all displaying an item is a use, and sometimes is the intended use (art knives) wether I like it or not.

Danocon, correct without the pure collectors we would have lost much throughout history. Especially when looking for the original forms and uses of "legendary" items and the dispelling of myths relating to them. Think of all the debates concerning the muscle car wars of the late '60s and the myths and legends created by the mid '80s. Factory cars rumored to run 11 second 1/4mi. Right, only the truly exotic (factory race cars). We had to go back and dispel these (myths) and owe true collectors, who saved many of the original examples in original condition and a fine state of repair, a thanks. It also allows us to go back and build true to form (and usable) reproductions. These collections are a benefit to society in many ways. They show us much about ourselves, where we have been and where we are going.

Jeff

Originally Posted by Danocon

... someone making scalpels out of obsidian. Have you any experience with these and do they resist the corrosive effects of the human body any better than stainless?

http://www.midwestlandcompany.com/ne...photo5_000.jpg This pic is a good comparison. The last time I encountered obsidian scalpels was in the hands of an adept opthalmologist (eye surgeon). They were very desirable blades in his hands. Like any glass, they fracture easily. Generally medics get into trouble if they leave instruments or parts thereof inside someone.

As a side note, it is the same with a sword cut. It is the velocity of the blade, not the power put behind it that makes it effective. .... That is why the technique of the cut is far more important then the power of the cut.

One also has to account for the sword's geometry. The curve (sori) of the katana's edge creates a single point perpendicular to the body where the cut begins. The points on the edge next to that are not perpendicular due to the curve. A perpendicular point has to push through the material where a non perpendicular point can slice into the material from the side. (Hmm, is this how a scything cut works?) After initial contact then the curve causes the blade to slice with considerably less resistance. Included in most (IMO this means good) technique is a slight degree of turning around the vertical axis of the swordsperson that enhances this slicing motion, and the blade becomes incredibly more efficient as a cutting instrument.

It is a poor contrast to shoot something at a static edge and claim that somehow that is a better blade. I like P&T's butter knife example though. Really for a bullet at speed, any wedge shaped object would split a bullet. It is cool to watch things like that in slo-mo.

Likewise, most people who are asked to cut with a katana will swing it much like an axe, a direct perpendicular chop. Then they wonder why they don't slip right through the target like in the movies.

I have often said that, setting luck aside, I would be more afraid of a master swordsman armed with a rusty lawnmower blade than a novice with the finest sword in the world.

Originally Posted by Mike Blue

I have often said that, setting luck aside, I would be more afraid of a master swordsman armed with a rusty lawnmower blade than a novice with the finest sword in the world.

LOL. I know some guys that I would find scary with a blunt pencil let alone a lawn mower blade.

PS the obsidian pic is cool.

Originally Posted by TURNMASTER

Great thread. Angular momentum at a constant speed is acceleration IIRC.

No disrespect meant Bruno, but if I can build something that some guy wants to display I get to charge him more for it and can make more of the daily tool for use for at more reasonable cost. And after all displaying an item is a use, and sometimes is the intended use (art knives) wether I like it or not.

Then again, if something is for display only, why even bother heat treating it, or use tool steel pattern welded steel instead of softer 'looks pretty' pattern welded?

I know this is going to sound weird, but I would not mind if the knife was a 'pretend' knife for someone who didn't use it. Because then the design and construction are fit for the intended use. Now, I understand that a knifemaker cannot build such things because if someone then actually tried to cut something with it, it would suck and your name would suffer.

And I understand that if knifemaking is your job, you need to pay the bills. I have been a consulting software programmer for 10 years before I got my current job. If the customer wanted to do something stupid, I would explain that it was stupid, but I'd still do what he wanted if he insisted.

For me it is more of a philosophical thing. And since knifemaking for me is a hobby and I don't rely on it for income, my situation is different. I can only make a very limited amount of razors / knives per year. And I make them because I like making them. If I can make 10 things in a year, I would rather make 10 things that will be used by someone who appreciates a quality tool. That way, my effort has not been for naught.