Honing razors on 200-400 grit stones

[Herrenberg]

@Gamma, if you would be willing to answer another question: which of those makers would you consider especially worthwhile? In the West, it is clear that Iwasaki has the best reputation, but I have no clue about picking other makers to explore, and I'd like to.

I've heard of kamisoris made from blue steel, but have never used one. Do you think it's a good razor steel? I know it's a good knife steel and plane blade steel and chisel steel, but I've always been surprised that it has not been widely adopted for razors. Any guesses about the reason?

 

[stone and strop]

I realize that the thread title seems like clickbait. Who would ever hone a razor on a 200-400 grit stone?

My answer: someone who had spent 3000 passes on a Shapton Glass 500 in order to get a ding out of a kamisori.

It's not just that kamisori. I've been buying messed-up Japanese razors on eBay, and trying to reshape them according to my standard, which is: the bevel is entirely flat. If you put the razor on a flattened fine stone, the scratches go all the way to the edge along the entire bevel. This can be a surprisingly hard thing to achieve.

I do know about the tricks, the pressing and the X-strokes and the windshield wiper and the tape and all that. I don't want to use them. I want perfectly flat bevels, and I am willing to pay the price for them.

That price is high, especially for the steels used in Japanese razors. So naturally I started to wonder about coarse stones, and that has opened up a whole new world for me. I'd like to report what I've discovered, and invite the advice of anyone who has swum in these waters.

Discovery 1: Slurry is the enemy

Slurry is a wonderful thing when honing on a fine stone. It speeds things up, and seems to aid in polishing. Yes, you can get some more refinement by doing some final passes with just water, and you should. But there's no harm in riding the slurry train as far as it will take you.

On a coarse stone, that is completely untrue. Kick up any slurry at all, and you are inviting edge dings. Tons of edge dings. It's just awful. You can feel the horrible rocks rolling around under your delicate edge, and the microscope will show just what a mistake you made in persisting at all, once you feel that.

So now I hone on coarse stones under a stream of running water. Exception: vitrified diamond stones. I'm not sure they even know what slurry is.

Discovery 2: Pressure is the enemy

Pressure makes slurry. It also invites unevenness. On coarse diamond stones, it makes scratches so deep that you're not really saving any time, because you're going to do even more work, later, to get rid of those scratches. Every one you don't deal with becomes a ding in the edge at the end of the process.

Discovery 3: Add those two together, and coarse stones aren't that fast.

A 300 grit resin-bonded diamond stone turns out to be a pussycat under light-moderate pressure and running water.

The Shapton Glass 220 turns into a barber hone. Really. The normal word on this stone is that if you don't use it with a lot of pressure, it glazes really fast. True. The interesting thing is that once it glazes, it puts quite fine scratches on the edge. Maybe 800-1000 grit? It's the same principal as a barber hone, and I think it comes from the combination of coarseness and a hard binder. It's a useful quality, because you can judge whether the bevel is truly flat without going up to finer stones, discovering a lack of flatness that was not apparent at the coarser grit, then falling back.

Another observation: running your finger over a stone, and judging its smoothness, is not proportional to grit if you are comparing two different lines of stones. The ones that feel smoother are more likely to make good coarse razor hones. Shapton Glass is tops in this area, above the 220, which is why I have ordered a 320 to complement my 500.

This is all still a work in progress, but it seemed like enough to relate, and to solicit your thoughts.

There is a saying in Carpentry I was told and pass on.
Know when to hog!!
There is a time for aggressiveness to expedite your journey. Knowing when to begin finessing is part of it.

 

[Gamma]

I think most vintage Kamisori are very good blades, so long as they weren't damaged through misuse. Personally, I value condition and size over brand. My whiskers don't care if they were cut by Tamagahane, White 1, White 2, or reclaimed steel from a junk yard. The smith's skills matter more than the materials... I tend to evaluate each blade on it's own merits, not based on who made it, when it was made, or out of what.

 

[Kyle89]

Gamma I love your writing. I'd bet money that you write professionally.

 

[Jasper J.]

IMO kamisori set a bevel angle of 1k is sufficient, 5k does not work. In the above 800x zoom picture, because of warping edge of kamisori, you sometimes cannot relly hone to the edge of the omote side. This is different from the western straights. To reach the edge, using a low number can save you thousands of useless laps.

 

[eKretz]

Are you sure that's 800x? It doesn't strike me as being that high just looking at the size of the bevel. The edge looks exceedingly smooth to be that high as well. Have you actually checked the field of view with some sort of reference such as a calibration slide? Even a finely graduated ruler with .010" or 1/64" graduations will work.

 

[Steve56]

The soft iron is an issue with coarser stones as Keith says. If I have to do chip removal/geometry correction I tape the omote to prevent it from wearing. If needed I can remove the soft iron later on finer stones, but I’ve never had too much soft iron on a used kamisori.

The only kamisori that I’ve seen that are ‘one piece’ are symmetricals and oddly enough, I have a couple (same brand) of WW2 vintage orihi that seem to be one piece of hard steel. My guess is that at that time when steel was plentiful and cheap, one piece of steel was cheaper than forge welding two pieces, but that is a guess. I have an older Yama Daii orihi that’s definitely bi-metal construction.

 

[Jasper J.]

Are you sure that's 800x? It doesn't strike me as being that high just looking at the size of the bevel. The edge looks exceedingly smooth to be that high as well. Have you actually checked the field of view with some sort of reference such as a calibration slide? Even a finely graduated ruler with .010" or 1/64" graduations will work.

I do have a calibration slide, in fact it can be up to 1000x, I just need to adjust it to the required magnification, but you misplaced the point. Look again, in this picture, the edge is not honed, which is not visible under the microscope.

 

[Jasper J.]

The edge is not honed.

 

[eKretz]

I do have a calibration slide, in fact it can be up to 1000x, I just need to adjust it to the required magnification, but you misplaced the point. Look again, in this picture, the edge is not honed, which is not visible under the microscope.

I'm afraid you're going to have to rephrase that. I do not understand what you mean. Is the edge supposed to be at the top or the bottom red arrowhead? The photo is not very clear. And what do you mean by "the edge is not honed, which is not visible under the microscope?" Are you saying that the apex of the razor is not in the photo?

Looking at the photo, it appears that the apex of the razor is near the top red arrowhead in your latter photo, however your description has left me scratching my head.

 

[Jasper J.]

I'm afraid you're going to have to rephrase that. I do not understand what you mean. Is the edge supposed to be at the top or the bottom red arrowhead? The photo is not very clear. And what do you mean by "the edge is not honed, which is not visible under the microscope?" Are you saying that the apex of the razor is not in the photo?

Looking at the photo, it appears that the apex of the razor is near the top red arrowhead in your latter photo, however your description has left me scratching my head.

It's not important, I don't need to explain this for you. Just remember that some areas on the kamisori edge may not be honed, if you do not use low-number stones.

 

[eKretz]

Uhh, okay...That's generally the case on every razor, and is pretty common knowledge as far as I'm aware...

 

[Jasper J.]

If it is common knowledge, why can't you understand what I'm talking about?

 

[eKretz]

If it is common knowledge, why can't you understand what I'm talking about?

I had no problem understanding the original idea. The part I had trouble understanding was what I quoted in my last post. Maybe because your grammar isn't very good?

 

[rbscebu]

The edge is not honed.
View attachment 1267668

Correct me if I'm wrong. The photo appears to show a double bevel. There is one bevel that is highlighted with the red arrow(s) and then there is a second bevel directly below the red arrow(s). Your course stone is only working on the second bevel (below the red arrow(s)) and not touching the first bevel (marked by the red arrow(s)).

Are you referring to the first bevel as the "edge"?

 

[eKretz]

He's saying that the honing work didn't reach the apex, but that it couldn't be seen without the microscope...I think....

If that is in fact the case, his post should have said "which is not visible except under the microscope." Which is what threw me - seeing that as-typed it said the exact opposite.

 

[Jasper J.]

Correct me if I'm wrong. The photo appears to show a double bevel. There is one bevel that is highlighted with the red arrow(s) and then there is a second bevel directly below the red arrow(s). Your course stone is only working on the second bevel (below the red arrow(s)) and not touching the first bevel (marked by the red arrow(s)).

Are you referring to the first bevel as the "edge"?

Sir, only because of the warping of the omote edge, the pic shows that the real edge (red arrow area) cannot be honed. In this situation someone uses tape, I use 1k to go on, otherwise there will be no apex on both sides.

 

[Jasper J.]

He's saying that the honing work didn't reach the apex, but that it couldn't be seen without the microscope...I think....

If that is in fact the case, his post should have said "which is not visible except under the microscope." Which is what threw me - seeing that as-typed it said the exact opposite.

So does it make you funny of my English?

 

[eKretz]

If it is common knowledge, why can't you understand what I'm talking about?

So does it make you funny of my English?

I wasn't making fun, just answering your question... You asked why I couldn't understand - with the implication that it was my fault - and I answered.

 

[LJS]

Surely you could see that without a microscope? That would reflect light from a distance without magnification it would sure seem.

Tape is one way to reach the edge but that may have been what caused that problem in the first place.

Do you have a NON-magnified picture? How does the omote look? Is there still plenty of hollow or has this kamisori been ground flat already? I ask those questions because I wonder if there is enough razor to set a bevel properly without tape.

A big second bevel what looks like extending a significant portion of the edge should be visible without significant magnification.