How do the kamis do this?

[RockFarm]

Hey folks,
I was wondering how the kamis manage to temper these excellent blades. I know that they pour water on them from a kettle, but if they poured on on side of the 1500+ degree steel it seems like the other side would not be tempered at all. So do they pour the water edge up? These are the questions that keep me up at night!
Actually any info on the process would be helpful,
Take care,
Jim

 

[Eric C]

Hi Jim
On a video footage, floating around on the net somewhere, I've seen them pour water on both sides. You are right about the hardening to occur only on the side where water was poured.
Cheers
Eric

 

[Kazeryu]

The forumites who etched their khuks might be able to shed some light on this.

If it's hardened one side at a time I would expect it to be plain from the hamon having a very different shape on either side.

 

[ferguson]

From http://www.himalayan-imports.com/kami.html

Water was the quenching medium for 2500 years or so. It was used in Nepal "since the beginning" and a kami's skill is largely passed down from one generation to the next. The hardening of the blade is really an art rather than a skill.

Bura was giving me a lesson in hardening a couple of years ago --"setting the pine" they call it. Pine = hardness.

Bura lectured as he did the work.

"Color is very important. See this color? The blade is not hot enough. See this color? The blade is too hot. See this color? It is just right. See the color at the tip? See the color at the cho? These all must be just right before you start to pour."

When the blade color was just right he began to pour from his pitcher.

"You cannot pour too fast and you cannot pour too slow. You must pour just the right amount at just the right speed. Watch the blade change color. You will see red, purple, green, in various shades and then black. If you do not see the color change seven times you have missed and must begin again. See it has changed three times already. There, again. And again. Again, and now it is black. It is finished and the blade pine is just where we want it to be. It is very hard here (pointing to the chopping area) and not as hard here and here (tip and bottom of blade). This knife is perfect."

I took a file to check the blade and Bura chuckled. "You are wasting your time," he said.

And I was.

--Bill Martino, 5/2002