Thread: Lapping a Nakayama

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. 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. 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.

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. (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....