Filing a crisp yokote line at tip of blade?

Robert_Phelps

Robert_Phelps

Joined
Nov 29, 2005
Messages
475
I took out a piece of steel today, and thought I'd try to figure out how to file a crisp line transitioning from the straight-ish part of a blade, to the tip (A "yokote", on a japanese blade.. or so I gathered..) But it just turned out smooth. How is it done?
yokote3.jpg

Is the tip's bevel ground/filed at a slightly different angle than the rest? If so, is the tip's bevel ground at a steeper angle, or a shallower angle than the main body of the blade?
Or, is the line there because the blade begins tapering, in thickness, to the tip?:confused:

Any help on this is appreciated
 
The Ji ( long flat of the edge) is formed with long straight strokes that go STRAIGHT off the blade,not up and around the Kissaki ( point area).After the Ji is established,the Kissaki is shaped by drawing the strokes down at an angle matching the angle of the tip.The line where they meet is the yokote.It is the intersection of the two straight 'cuts' in the edge that make such a sharp facet line.Using draw filing,stones,and hard backed sanding blocks makes this more distinct.Any method that promotes rounding,such as belt sanding and buffers, will diminish or remove the yokote.
Stacy
 
So, to clarify... is it initially a compound angle on the kissaki, and a single angle on the Ji, that makes the line where they meet distinct? Then just always follow those same strokes throughout the polishing process with stones/backed paper to keep it?

Thanks for the help:)
 
The yokote is the intersection of two planes,one of the ji and the other of the kissaki.The kissaki is often a convex surface,the ji is usually fairly flat.If the kissaki is flat,too,then you get a tip like a western tanto.
 
Robert asked me for a more detailed explaination, I'll try to describe it as good as I can.
Lets assume you have a 1.25" blade with the ji roughly profiled in on the shinogi/mune and the ha (I don't cut the mune until the very last - just the shinogi at this stage).When these surfaces are about 80% filed in it is time to start the kissaki.First,shape the kissaki profile (just the end profile,not the kissaki-ji).At this point you have two bevels going straight down the blade above and below the shinogi,and ending at a blunt curved tip.Approximately 75% below and 25% above the shinogi.The shinogi-ji and mune-ji make up the top 25% and the ha-ji is the bottom 75%.We are only concerned with the ha-ji right now.
The kissaki-ji will make a 145-150 degree angle with the ha-ji (for the purpose of this example),and is slightly curved (lets assume it is a chu kissaki ,or medium point).File from the mune perpendicular to the kissaki (not perpendicular to the ha) and shape the bevel,using smooth strokes that go from saki (point) to yokote.By keeping the file cut downward and perpendicular to the edge you will make a sharp line as you intersect the ha-ji.The trick is to keep the file flat,don't go around at the yokote like you would if filing the tip of a bowie knife (imagine you are using a 2" wide file,and making one straight cut).If you are making a powerful kissaki with extra thickness,and a convex ji,file it that way,or you can make it flatter, like the ha-ji, for a thinner and sharper kissaki.Either way the yokote will still be a sharp line.
Once the kissaki is established (and the yokote is defined) you will have to alternate from a stroke down the ha-ji to a stroke on the kissaki-ji,back and forth,etc.Turn the blade over often and do a little on one side then a little on the other. When the kissaki and ha are getting well along the way start adding the shinogi and mune to the series of cuts. At this point the shinogi will have moved up towards the mune a good bit.Don't worry it will come back down and be established as you bring the shinogi-ji along.
Once the blade is 90% shaped it is time to go to stones or a HARD sanding block and GOOD grade paper (I'll describe paper).As in filing,all strokes should be smooth,long ,and in one direction only (usually from machi to saki) .Start at 120 and do EXACTLY as you did with the file.go to 220 and then 400.Change the paper often, fresh paper cuts better.When the blade looks exactly like you want it to,and is about 95% done,do the HT,creating the sori and hamon.
Go back to the 220 paper,400,right on up to 8000 if you like. Finish with a hard leather strop block make by taking a 2X2X8" wide block of very hard wood and surfacing the bottom with hard leather.Charge the strop with green chrome polish,rouge,ZAM,or whatever final polish you like.I rout deep grooves in the side for a good grip and to keep fingers away from the EXTREMELY sharp edge you are polishing.Use smooth ,slow, firm strokes to polish the edge (and make the hamon pop).Recharge the strop very often.
A proper sword jig is a good idea to do all this filing ,sanding,and polishing safely.It is somewhat like a sawhorse with the top padded with leather and a clamping method to hold the blade firmly down.
Be aware that polishing a katana is very dangerous if absolute attention is not applied (and fairly dangerous when you are paying attention!).
I hope this helps a little.There is,of course a lot more to it than this,but this will give you the basics.
Stacy
 
I left out a trick that works well.

Use a piece of popsicle stick as a stop when polishing in the yokote.
Hold it with one hand in place as you work the polish block or hazuya stone on the kissaki.
Some use a piece of duct tape as a stop.
 
bladsmth said:
I left out a trick that works well.

Use a piece of popsicle stick as a stop when polishing in the yokote.
Hold it with one hand in place as you work the polish block or hazuya stone on the kissaki.
Some use a piece of duct tape as a stop.
Click to expand...

Thanks for the tip. I have been copying a video clip I saw but instead of a waterstone I use a sharpening stone with some success, but more failure.

Are there any good videos for sale that detail this process? Japanese blades in general? I'm trying to understand all you wrote with a glossary of the correct terms and my head is spinning. If I see someone do something as they explain it I understand WAY better no matter the subject.
 
Last edited:
One of the best guides to polishing Japanese blades is the book " The Art of Japanese Sword Polishing" by Setsuko Takaiwa
You can get it from Amazon or ebay for about $45.

It shows and explains the full procedure from every angle in great photos and excellent description.

You have to read the book completely through about five times before some of the things suddenly make sense. Use a set of highlighters and highlight all the main terms/words in yellow, and the main procedures in green. If you skip a section that seems of no interest, you will miss some needed term, info, or process later on. The principles learned can be applied to hybrid polishing.


There are several videos on Hybrid polishing, with Walter Sorrells doing a very good one. I would suggest a person who plans on doing Japanese style swords and knives with hamon getting the entire set of Walter Sorrells DVDs.

Videos on traditional toigi are almost all in Japanese. They are also very expensive. There is one in English, called Japanese Sword Polishing, but it is hard to find. You might try smartflix.
 
You must log in or register to reply here.
Back
Top