Lapping a Nakayama

Hey all,

So after talking to OLD_SCHOOL, it seems that it's really my decision as to whether I should lap my new stone. It doesn't need lapping in terms of removing chips or inclusions. I told him that I had decided to just leave it the way it is, but I'm beginning to second guess that.....I know it's really up to me, but I can't help but wonder if it would perform better with a good lapping.

So my question is: For those of you who had an unlapped Nakayama and lapped it, did you notice an improvement in performance?? The only way for me to check for flatness is to actually lap, so that's of no help to me.... Also, I was thinking it would give me a nice fresh surface as I don't think this stone has been lapped ever.

This wouldn't be an issue at all if it didn't have the lovely kanji on the surface.....On the plus side, there is a faint Maruka stamp on the end of the hone that would survive.

I'm not looking for advice, just would like to hear people's experience with lapping Nakayama's and how it affected their performance as it might sway my decision.

Thanks!

P.s. This is the stone (just another excuse to show it off...)

I lapped my Oohira razor hone with a 325 DMT. It left a rough finish that took a while to smooth out, durring honeing. I was not aware that the roughness of the stone was a direct consequence of the flattening with a rough plate, compared to the relative grit of the hone.

So really I can't say if lapping yours will make it better, but I know if you do lap it to insure you polish it with finer grit than 325 :p

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Originally Posted by DwarvenChef

I lapped my Oohira razor hone with a 325 DMT. It left a rough finish that took a while to smooth out, durring honeing. I was not aware that the roughness of the stone was a direct consequence of the flattening with a rough plate, compared to the relative grit of the hone.

So really I can't say if lapping yours will make it better, but I know if you do lap it to insure you polish it with finer grit than 325 :p

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Well I have a DMT 325 grit, but was considering just starting with a higher grit and taking my time. i.e. something like 1000 grit wet/dry and then once it's perfectly flat going to 1500 then 2000. It may take a while, but I don't want a rush job.

Oh, and this is if I actually decided to lap it. I'm still on the fence about this one!

When I got mine from Hida Tool in Berkley, CA. it was already flat, lapping it only took out a scratch or two, it was already flat enough given the ease it lapped flat.

I don't foresee any difficulty in lapping it if I decide to. It's just hard to decide because I'll lose the wonderful Nakayama Maruichi kanji....but what if I lap it and it performs much better, than it's worth it...but if it's not that much of an improvement than I lost the kanji in vain....

But I did buy the stone as a finisher not for the kanji.....

Do you see why this is difficult for me? :cry:

Oh yes, I don't envy your choice :)

However if it where mine I would not worry about it. Many photos, and lap, move on... But thats me.

I have three Nakayama hones, one Namito and two Asagis. I have lapped all three of them. All three had "lovely kanji" on the surface but I did not buy collector pieces. I bought hones. Their performance was of tantamount importance to me. I honed before and I honed after. Each honed significantly better after.

I have no regrets.

Well I think this is something that I will need to sleep on...

Utopian has a good point though, and I did really buy this stone to be used as a hone, not as a collector's piece. He also really sways my opinion by saying that he has noticed an improvement after lapping.

OLD_SCHOOL also does have a point about not wanting to waste stone. But since it's pretty flat as is, I wouldn't need to remove too much material anyways. The stamps would wear off eventually anyways, so if I were to lap it I wouldn't have to watch them die slowly! Also, I could better appreciate the stone's natural appearance with no stamps in the way....(this is me rationalizing :p)

I think I am siding more with the idea of lapping it just to try to bring out the stone's full potential. I'm still going to sleep on it, as making a tough decision at almost 2 AM is almost never a good idea.....

I will report back with my decision tomorrow! Thanks for all the replies everyone.

EDIT: I did a quick little photo-shopping on MS paint to see what it would look like (roughly) with no stamps. I think it looks pretty damn sexy actually!

Great looking PS pic, one reason I love natural hones, beautiful :D

I tested my Nakayama before I lapped it in an attempt to keep the kanji, but the edges I got of it was good, but not great, and my straight edge did tell me the stone could be flatter, so I lapped the stone. The edges improved and since I'm not a hone collector it was ok for me to lapp it.

Well I thought of a quick little way of testing for flatness. All my hones have been flattened to DMT flatness, so pretty darn flat. I decided to use the hones themselves as my flat edge, and to use a little light to test for un-flatness.

I first took 2 little coticules that were lapped using my DMT and tried this method. I put them together, and shone the light on the otherside of the stones. I tried to move the light around behind them as well as slide them around to see if it would make a difference. But no light shone through at all.

So then I tried the first coticule on the nakayama. I did the same thing, put the sufaces together and shone the light from behind. There were quite a few places where the 2 stones didn't make perfect contact as a bit of light shone through. I tried the same test with the second coticule, and this yielded the exact same result.

I know this isn't a perfect test as no light shining through doesn't necessarily mean a perfectly flat surface throughout the entire width. But, it clearly showed me that the nakayama's surface wasn't perfectly flat.

So I will see how I feel about it in the morning, but I'm fairly certainly I'm going to lap it tomorrow as I have more evidence to assure me that it will benefit from lapping.

I guess you could ask; however I doubt he stone has been stored in the way a using stone should be stored, but rather the way whole sellers store things waiting to be sold. When was it cut and stamped?- probably not yesterday.

one cuts the cord and baths a newborn, no? the gestation is over now, yes?

I completely disagree with the claim that lapping is a waste of stone. Actually, I think using a great stone with a poor surface is a waste of a stone.

When (if) you start to lap it, you will get a sense of how flat it is. If it seems fairly flat already, then don't bother going further. I lapped mine because they clearly were not flat enough for me. I probably won't need to ever lap them again in my life. They won't remain perfectly flat but they will be close enough to be perfectly functional because the wear will follow my honing path.

Well I do lap my naturals, as I couldn't live with the thought of them not being perfectly flat. :p But O_S has a great point about barbers 100+ years ago, as they probably didn't have perfectly flat hones.

I have chosen to lap my nakayama after seeing it wasn't as flat as it could be. I'm not saying that it's not useable now, because it clearly is. I just like to know that all my stones are as flat as can be, but that's obviously a personal preferrence. I'm a little OCD like that. :o But I know I'll only need to lap it once though, as I'm definitely not the type of person to lap one after every use. At least not my naturals anyways. I've lapped my norton a few times, but that's because it takes a lot more abuse and it's not so precious to me!

I will be sure to take more pictures of the kanji before hand for my record. I plan on lying a piece of 1000 grit wet/dry paper on my DMT (a known flat surface) and lapping it on that. I also have 1500 and 2000 grit that I will take it through to help smooth out the surface more.

Thanks for all the replies, it did give me some insight. Lapping a natural stone is indeed not an easy decision and is a very personal choice. I'll shut my bathroom door OLD_SCHOOL so you can't hear the nakayama scream when I lap it. :rofl2:

If and when I ever get one of the Nakayama stones I will lap it. I don't lap my naturals every time I use them but I do lap them when I get them. It is too bad that you have to lose the Kanji but unless it was bought as a collectible,I agree with Utopian,I would certainly lap it to get the best performance out of it.

Well it's lapped! And it's just as beautiful as before. ;)

I took my time doing it, and rounded off the edged lengthwise as well as side of the edge by the chip a little more so it would not interfere with the surface. The stone wasn't too far off flat before, but there is a noticeable difference now. When I began lapping I could see exactly where the high/low spots but before too long it was flat. I went through a progression of grits and finished on 2000 grit wet/dry and smoothed over the bevelled edges by hand with the 2000 grit paper.

It looks really good, and I tried it out. There is a noticeable improvement in the feel when I'm honing on it, so I guess the increased flatness made a slight difference afterall. And dispite what it looks like in the picture, that dark line on the top left is not a crack, but just a dark line in the surface. There are actually more in the side on the stone, kinda pretty actually.

Anyways, I'm pleased I did it, and I think it looks great now. :tu (I'm not the greatest picture taker....sorry)

I don't get the part about never lapping again either.

Still the stone is wearing, swarf left on the surface- I gues you could scrub it off.

A few swipes on the lap is a good thing imho.

We can see lots of old hones that were worn terribly out of flat- but we cannot talk to that guy or know if he really knew anything or not.

But we do know that the old method of lapping is stone on stone and that those who sharpen well continually for years know to keep the stone flat.

This is not specifically related to lapping but I found a Kanji online dictionary if anyone would like to take the time looking it over.

Japanese Kanji Dictionary


For instance type in Nakayama and it comes back as the correct Kanji. It could be handy at times.
http://www.saiga-jp.com/cgi-bin/dic....47977258_78321

I bought a Nakayama Maruichi this year and was told that lapping would mostly be unnecessary on this type of natural stone. However, since I am still working on my Bachelor's Degree in Honemeistery, I feel I need all the advantage I can get so I drew silver pencil lines on the stone and put it on the DMT 8C. According to my pencil lines, this hone was not quite flat so I continued until the lines were gone. Then I put it on the DMT 8EE to smooth out the stone surface a bit.

The stone works fine and has nice feed back feel to it. I'm glad I bought it and I'm glad I lapped it. Don't knock it 'til you tried it........ JERRY
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They have to be lapped occasionally. That's all there is to it. How often depends on how you use it; what you use it for.

European water stones were often sold with a rubber, right? Their purpose is not just to create a slurry for speedy work, but to clean and condition the stone so it works at its best.
It's not all about staying flat....

There's simply no reason not to lap a natural hone. IIRC, OLD_SCHOOL's reason for not lapping was to extend the life of the hone. If a hone is dished, it is because the maximum wear is on the lowest point. The lowest point is what defines the useful life of the hone, so lapping down to the lowest point doesn't shorten the life of the hone in any way.

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Originally Posted by Chimensch

There's simply no reason not to lap a natural hone. IIRC, OLD_SCHOOL's reason for not lapping was to extend the life of the hone. If a hone is dished, it is because the maximum wear is on the lowest point. The lowest point is what defines the useful life of the hone, so lapping down to the lowest point doesn't shorten the life of the hone in any way.

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Very interesting point!

FWIW, I lap both of my nakayamas. I honestly think I get better results, at least in the feedback and feel when honing, after lapping. And I'm pretty sure it's not just in my head :shrug: I will say that my kiita with nashiji is very soft, which may be why it requires more lapping (it actually raises a very very light slurry on it's own), and I haven't had the karasu very long, but it is significantly harder and may not require lapping as often, if at all.

I guess there is a fine line between a glazed hone
and a hone with a grit that you create
by lapping with coarser materials than the hone actually is.

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Originally Posted by 0livia

I guess there is a fine line between a glazed hone
and a hone with a grit that you create
by lapping with coarser materials than the hone actually is.

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If what you're saying is that there's nothing fine enough to lap a japanese hone without lowering its fineness, I have to disagree.

I finish lapping my coticules and Charnley Forest hones on 1000 grit abrasive paper even though they are finer than 1000 grit and they don't drop down in fineness because of that. The reason is that the fineness of the hone depends on the fineness of its own abrasive particles. I think the 1000-grit scratches that might theoretically be left on the surface of the stone have very little effect. Besides, if there are any scratches left from the abrasive paper, the first razor you hone on it will quickly smooth them down by removing them.

What I'm saying is that this fine line has to be met.

Quote:

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Originally Posted by 0livia

I guess there is a fine line between a glazed hone
and a hone with a grit that you create
by lapping with coarser materials than the hone actually is.

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Quote:

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Originally Posted by 0livia

What I'm saying is that this fine line has to be met.

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I'm not understanding what your point is ... we always lap hones with coarser materials and they don't "create a grit". On the face of it, what you're saying makes no sense. A hone consists of abrasive particles in a softer media or "carrier" that is worn away, releasing the abrasive particles. If you remove the media or carrier with a coarser material, there is no way that you are changing the grit of the hone because you are only removing the carrier to make a flat surface from which the abrasive particles are released.

I should have quoted, I guess.
Someone wrote that his hone felt coarser after lapping it.
Thats what I've experienced with one of my Frankonians as well
but it was a surface I've created and had nothing to do with the hone.

An option in this case, where the lapping leaves the
stone feeling a bit coarse, is to simply use a slurry
stone of the same material. Finer grit sandpaper is
probably feasible as well, but I've never used it.

- Scott

I have two and they have been lapped once when new but the next time they will be honed is when I can see or feel they need it and that will be a very long time I imagine.
Not to hurt anyone's feelings but I think at times we are a little to picky about keeping our hones 100% flat all the time.

On the subject of lapping nakayama:
So Yamashi.ta -arguably one of the most experienced experts on Japanese hones in the world- told me to use a diamond plate to lap my hones. 600 or 1000 grit is what he uses. It keeps the honing surface flat and fresh.

He laps before each honing session. I lap every couple of honing sessions, since my honing is less intensive than his. Lapping is -not- a waste of stone if you just lap until it is flat again. Because the material that is removed is typically on the surface that you don't use. If you would, then it would wear down the same as the middle of the stone.

If you read old text that include advice on sharpening there is always mention on lapping-though I do admit it is often minimal information usually offered almost as an aside.

So yeah, in the old days it seems there was less emphasis on perfection, but they were surely aware it needed to be done. But we need to be careful to understand these kinds of books are often written for novices to work at a certain level. If you intend to do work at the highest level it will require some additional effort and attention to detail.

The Complete Japanese Joinery and Odate's Japanese woodworking Tools, both of which provide instruction on the care and use of tennen toishi include methods for lapping.

They are not razor books, but they are examples of teaching texts that provide info every beginning sharpener should know.

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Originally Posted by Bruno

Yamashi.ta .

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Watch your language Bruno ! ";" :roflmao :roflmao

Bruce mentioned lapping away parts that are not used and Chimensch said he finishes his lap on 1000 paper. Here's some food for thought:

As i have mentioned before I do use a little bit of pressure and scrubbing back and forth(side sharpening style) at the beginning use of each stone. I usually do this across the width at the ends of the stone, both bevel at the end and spine at the end. (And somewhere near the end of the time I'll spend on that stone i do it some more with a very light touch)

It works extremely well I believe and the cost is free- the material would just be wasted lapping back to flat later.

Also progressive lapping is a bit wasteful. One thing- the need for a coarse grade shows you have let the stone go too far. And that little bit more to refine the scratches on the hone surface doesn't really do anything beneficial(as far as I know)

Using the whole stone, minimal frequent lapping are the best ways to conserve the stone- besides not using it.

I never check my hones, or pencil grid them so I thought maybe I should before writing all this- so I did. nakayama on nakayama:12 strokes(not laps) and almost all the pencil was gone(i would use it like that) 12 more and it was all gone.

it would take some very sophisticated state of the art measuring equipment to determine what was lost. I may sharpen 5 or 10 or 20 razors before i need to do it again; it just depends on how much use those razors require.