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Doug Ayen

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update [Feb. 5th, 2004|09:27 am]
Doug Ayen
Wow, it's been a while. I haven't been completely lame, just busy with other things for the most part.

Most recently, finished off an axe for a commission (wrought iron with welded on homemade steel edge, ash handle), but I have also been spending quite a bit of time on the various tantos and other knives that had blades heat treated but not polished & etc. I must say, grinding out surface rust pitting on a blade that was near-perfect after HT is discouraging, but reminds me I just can't let the blades lie around without protection or at least finishing them up and sending them to rust at someone else's.

I definitely need to get a milling machine, the thought of hand-cutting out a dozen guards is pretty daunting. I'll be checking out the local metalworkers list, see if anyone has a machine they're not using, but most likely I'll be buying a mini-mill from Harbor Freight. Yeah, the machines are crud, but this will let me get started, and hopefully I'll be able to pay for a real mill using the profits from these knives. We'll see.

Polishing tantos is a slow, hand-eye coordination intensive process. Even cheating by using machines, it still takes over an hour per knife to get it right. I start by loading up the high-speed grinder with A65 trizact and the other, a Bader III with a small drive wheel, thus slower speed, with X30 Norax. I start on the x30 grit, and if I find a scratch or pit that is taking too long on that grit, I move to the A65 and remove it. Once all the knives I'm currently working on are at the x30 finish, I move that to the high-speed grinder and load an X15 onto the Bader. Repeat with A6 and I'm done with the grinder work. A6 is about 2000 grit, and really leaves a mirror finish with barely noticeable scratches -- hit it with a buffer, and you get a true scratchless finish. On differentially hardened knives, however, hit it with a buffer and you'll remove the visible hamon, which was the point of this exercise.

Next update will probably be Sunday, by which time I should have some finished blades to brag about.

--doug
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Comments:
[User Picture]From: justinjs
2004-02-05 03:58 pm (UTC)
Excellent. I'm looking forward to seeing and reading about those tanto blades.

So, how do you get a really great finish on a blade while leaving the hamon intact?
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From: dougayen
2004-02-06 01:57 pm (UTC)

Re: good finish

Normally, you spend a 10-15 year apprenticeship in Japan under a master polisher, learning the names, schools, styles, and works of all the great swordmakers so that, should one of their pieces fall into your hands, you'll know how to best restore it. Oh, and you also learn how to get a mirror-bright yet dark and clear polish on a sword while maintaining the edge geometry, outline, and how best to bring out all the features of a Japanese blade. You'll also have several thousand dollars worth of polishing stones, and have spent several thousand hours practicing.

As I don't have this experience, I improvise. To get a good base polish, I use a grinder et on a low speed. When this is done, the hamon is usually visible, but not terribly bright and clear. To bring it out, I either etch in hot vinegar, or (the method I'm working on developing now) use a polishing compound and a leather pad on a detail sander to rub out the blade, which leaves a bright and shiny hamon and a matte background. A method that also works well is the late Bob Engnath's method, www.engnath.com, go to "The Manual" then click on the "polish" link.

--doug
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