Thread: Japanese razor honing

Hi, and thanks for reading, because I really need some help. I have a few very nice Japanese razors, all of which have a dull "factory" type edge on them, and I have been trying to get them sharp using my stones, but no luck. I just don't know what I'm doing wrong, and I hope that someone here can give me some simple pointers.

So here's what I tried. I used a honing pattern similar to what Jim R. shows in his YouTube video -- 10 back and forth laps with the side WITHOUT the writing against the stone, followed by 1 stroke (or 1/2 lap), spine first direction, with the side WITH the writing against the stone. (I don't use concave or convex, because people seem to mix those up, and I also don't use ura or omote, because I know that I will mix them up.)

Anyway, I tried to put light pressure on the edge as I was doing the laps, but all of the wear I noticed was on the part of the "wedge" that is midway up the blade. Also, with even light honing, I notice now that the wear is not even!! How could that happen with just a few strokes?

As for the stones, I used a Belgian coticule and then two natural Japanese stones that I am evaluating right now for a purchase. I can see that the Belgian took off a lot more steel in a lot fewer strokes, but nothing I did got me any closer to shave ready sharpness.

Thanks.

Originally Posted by OLD_SCHOOL

My theory is that this comes from the fact the razors are all hand forged, so some unevenness in the work may be natural, since it's humans making them and not machines.

I think this is correct, it is observed in traditional japanese knives too, except the really high end ones because they are hand flattened during the polishing process.
As far as jigane, although its not true iron, that's what its referred to may be for ease of translation, its just very low on carbon and thus very soft.

Ok, this is just the kind of information I need, but can you give me some more details about the progression to follow? I don't think I need a whole tutorial, but if you can just tell me which stone to start with, how many laps, when to stop? Thanks!!

For reference, I have a Belgian combo hone, a nice Nakayama finishing stone and a balsa CrOx strop.

BTW, I got the razor you sent -- very nice looking! Thanks.

Use a 12K. You will get a lot of hone wear especially on the convex or side without the writing because of the way the blade is. That high point on the blade will take the full brunt of the honing.

The art in honing these things is in knowing how much pressure to exert as you hone. Of course this assumes all you need is a touchup or moderate honing. Anything more or if you need the bevel reestablished is a totally different problem.

Hmm? If you think about it Gents:
Let's say you must remove x from the edge to become sharp. what difference then does it make whether you spend 3 minutes on 1000 or 3 hours on 8000.

If you will notice in the pictorial demos pressure is applied pressing the omote onto the stone- pressure directed to the edge bevel- the point I believe, as I have pointed out previously, is to make sure you are not over-abrading the low carbon steel jigane.

As is usual it has less to do with what you use, more to do with how its done
iirc fwiw et al ji-gane means earth-metal or sometimes called mother metal. ha-gane means edge-metal

Yes you can do less strokes with lower grits and more strokes with higher and if your just interested in removing metal your right but the degree of finess to the edge will not be the same. No different than taking some extra coarse sandpaper to wood as opposed to extra fine. You can remove the same amount of wood but the finish will not be the same.

Originally Posted by JeffE

Hi, and thanks for reading, because I really need some help. I have a few very nice Japanese razors, all of which have a dull "factory" type edge on them, and I have been trying to get them sharp using my stones, but no luck.
.............

Thanks.

As others indicated hand forged and hand honed by the blacksmith...
This tells me that the shape of the edge reflects the hand of the blacksmith
and the shape of the stones he used to do his shaping.

It is possible that you can use a light hand and feel your way along
the bevel. The edge should be very hard and not respond to the tooth
of the stone while the bulk of the blade being softer might tug.

Use a marker often so it is easy to what part of the blade is touching
your hones as you feel your way along it.

If the shape is not even close to your well flattened hones consider using
a set of abrasive films on a flexible base (chilled, stiff modeling clay comes
to mind) and use a pull honing stroke.

Use the marker a lot. The flat side only gets 'touched' while the bevel
sees lots more of the stone.

I read some place that Japanese knives can have steel harder than R65
bonded to steel softer than common nails. It can chip and do odd
things on a hone. Arkansas (quartz) hones may just worry it into shape.

Jeff, as you are hearing, and agreeing I think a lot of your work is getting concentrated on the soft stuff. the hard stuff shows gray in slurry, but the soft (esp. true with the soft iron backing) is black. the low C steel will show up blacker that the edge material. Maybe that can keep you on track.

A new razor will develop a flat. If you look over the pics in the wakamisori sharpening thread you will see that noted as a must have aspect.- two flats on the omote.

If you think the flat @ the shinogiji / the grind line is overgrown; you can tape the razor for this first setting. If you want to undo it later it will be easy enough. Just make sure you start the tape so it covers the flat on both faces.

Use two hands (rt hand'd) use finger tips on your left hand to press down on the edge bevel with the right hand supporting. try to move the razor with just the left. not 100% easy but try to get into that groove. Now let the rt hand torque the edge onto the stone with lift at the back. Dont lift it off just lighten it up. add enough power to keep the predominat lft hand moving the razor. The right hand is both guiding the edge (into) onto the stone as well as guiding its X path across the stone.....

That may be confusing so I'll stop and see what happens next to you

Originally Posted by OLD_SCHOOL

Hagane is one word and uses one character 鋼 which means steel.

I thought it was the same kanji kane. As in jigane; mokume-gane. Ha is the Jp word for edge, the edge of nihonto is ha. But at least now you know what jigane means.

Here an explanation of the constuction of traditional Japanese kasumi knife (which is similar to what a razor is)

Craftsmen forge kasumi knives by joining a piece of soft iron with a piece of carbon steel. After forging, hammering, and shaping, the carbon steel becomes the blade’s edge. The soft iron portion becomes the body and spine of the blade. This reduces brittleness and makes sharpening easier

this is taken from Korin - Fine Japanese Tableware and Chef Knives, which is one of the Suisin owned brands.
I guess the translation is iron which is an earth metal.