Shapton Ha No Kuromaku 5k vs 12k

[Dundee]

I got both of these as a gift back in December and I swear the 12k is actually coarser than the 5k. I thought maybe it was a quality-control issue, so I exchanged the 12k for a new one, but now this one also feels like it's more coarse. The 5k leaves a mirror polish and when I move on to the 12k it leaves scratches--and yes I'm cleaning off any left over swarf. What's more is that just the feedback of grinding on the 12k feels way rougher than on the 5k. Can't really notice a difference in sharpness or comfort of shave between the two though. So it's not really a huge deal in that regard, but just kind of feeling like the 12k was a waste if I could get the same results on the 5k.

I'm wondering if it's an effect of using the two hones to flatten each other. Either the 5k is finer than it should be as a result of being lapped against the 12k; or the 12k is coarser than it should be as a result of being lapped against the 5k. When I'm done, the surface of each is as reflective as glass. However, I tested this theory by polishing a few knives on both to wear away the top layer of the hone and get to the "true" grit underneath, and to me the 12k still felt more coarse.

Is there any room for perception just not being fact? Maybe it just feels coarser because it's cutting more aggressively than the 5k? I'm just kind of feeling like I don't need the 12k. I mean sure I guess it is useful for lapping the 5k, but could a diamond plate do that and get it done in half the time? My thought against that, is that a diamond plate would leave the 5k surface so rough I couldn't finish off it. But I also wonder if I'm just saying that to try to find some way to appreciate the 12k.

So now I'm doing a weird half-backward progression of honing on the 12k, finishing on the 5k and stropping. "If it works don't fix it," comes to mind, but it bothers me a little.

Anyway, not really a review but just sharing my impressions and wondering how other peoples' experiences have differed.

 

[bluesman 7]

You might try lapping down a ways and seeing if the problem is a surface problem. I've heard of Norton water stones that had to be lapped in excess of 1/8" to get down to 'the good stuff'.

 

[kohalajohn]

I'm not sure if your method of lapping the two stones on each other would create roughness. I rather doubt it, as the diamond plates we use to lap, are even more coarse.

But in addition to that, your method will lose the flatness. Eventually hones will dish. And after a long time of rubbing them against each other, the coarse one will impose its error on the other one, making the other one slightly convex.

They will feel flat to you when you rub them together, but they're not flat. They are just agreeing with each other. The belly of one is perfectly fitting into the dished valley on the other.

Atoma and DMT make excellent diamond lapping plates. We all use them and they don't leave any roughness problems.

 

[kohalajohn]

Also the Shapton faq says that you can lap shapton stones against each other. They refer to three stones to avoid the "agreeing" problem I mention above, but evidently it does not cause harm.

I have three new shaptons and I am thinking of maintaining them by three stone lapping.

 

[Dundee]

Yeah, a diamond lapping plate is still on my to-get list, but that's always why I'm kind of frustrated because I opted to get the 12k instead of a lapping plate.

 

[kohalajohn]

Getting the 12k was not a mistake. It's an excellent grit to shave from. And Shapton is well respected.

Atoma 1200 is a well respected lapping plate. Atoma Diamond Plate (sharpeningsupplies.com)

If you have stone kitchen counters you can save money by just holding down a sheet of 400 grit wet/dry sandpaper on the counter and lapping on that. Dampen it and it sticks better.

I've done it both ways and both work.

 

[bluesman 7]

A bit off topic, but I consider the Shapton pro 12k to be a pre finisher. I found the edge to be on the harsh side and needing something to follow it. Not a bad stone, just not a finisher. YMMV

 

[kohalajohn]

Bluesman, how do you view the Naniwa 12k?

Is this something about the JIS versus ANSI thing, so a shapton 12k may be less fine than a Naniwa 12k?

 

[bluesman 7]

Bluesman, how do you view the Naniwa 12k?

Is this something about the JIS versus ANSI thing, so a shapton 12k may be less fine than a Naniwa 12k?

I normally finish on a Naniwa 12k.

I didn't think too much about what makes the Shapton Pro 12k different than a Naniwa 12k. I just know that the resulting edge felt more surgical and unfinished to me. I only tried the Shapton Pro once, so there is that. I was able to tame that edge on a clean leather strop for what that's worth.

 

[kohalajohn]

The Nani 12k gets a lot of love here.

When I replace my broken one, I'm getting the double thick version.

 

[Dundee]

I thought about getting the Naniwa 12k, but I wasn't sure I was even looking at the right one, and it seemed a little more expensive than the Shaptons.

bluesman7, maybe the 12k felt more surgical to you because it also cut more aggressively than you were expecting?

One thing that's interesting about the 12k Ha No Kuromaku is that the U.S. marketed "Shapton Pro" is apparently identical to it, except that here they market it as 15k.

 

[kohalajohn]

Market it as 15k. Interesting.

Again, it seems that above 8k, the ratings system is somewhat all over the place.

I'm starting to think there are things more important than the grit size. What kind of grit? What binding medium and how fast does it release particles? Do the particles break down to smaller sizes or do they just dull their edges? Are the particles all the same size, or do they vary? Are the particles shaped like soccer balls or like large cornflakes?

On and on, down the rabbit hole.

I think it's time to leave the computer and build a cocktail.

Happy weekend everyone.

I'm leaving my home office and going upstairs to play with the young boys who broke my Naniwa 12k.

 

[Dundee]

Market it as 15k. Interesting.

Again, it seems that above 8k, the ratings system is somewhat all over the place.

I'm starting to think there are things more important than the grit size. What kind of grit? What binding medium and how fast does it release particles? Do the particles break down to smaller sizes or do they just dull their edges? Are the particles all the same size, or do they vary? Are the particles shaped like soccer balls or like large cornflakes?

On and on, down the rabbit hole.

I think it's time to leave the computer and build a cocktail.

Happy weekend everyone.

I'm leaving my home office and going upstairs to play with the young boys who broke my Naniwa 12k.

Yeah, the Shaptons are a bit novel in the fact that they're "ceramic whetstones" and not your typical waterstones, so that might have some differences up at that grit range. Even within their own grit range, I've seen many suggest that some grits are more suited to carbon or stainless steel than others.

I've even heard a few people say they prefer the finish off the Shapton's 8K for shaving than off the 12K. It has me curious, but not enough to plop down $80 on an 8K just to see.

I've always been a Norton fan and was initially going to get their 4k and 8k but I've heard they dish if you look at them sideways, so went with the Shaptons to try to avoid that.

Not saying that I regret the choice, but it just seems weird that the 5k seems finer than the 12k. Maybe it just feels like that because I'm using a Gold Dollar with very soft carbon steel. I did try out a couple of knives in ZDP-189 and D2 on the 12k and they seemed to take a polish with less scratches, so I wonder if steel hardness has something to do with it.

 

[johnb65]

My Shapton 12k feels and looks under the microscope, to be coarser than my 8k one. I have no idea why this should be but I have other stones to finish with so the Shapton sits in the box until I can understand the problem.

 

[CollegeGroomer]

I also notice the Shapton 12k feels a little coarse for a finisher, so it’s not only you guys feeling that. But it still delivers good edges, especially before the 30k or my other naturals.

 

[Dundee]

Well, I replaced the 12k with the 8k and have noticed it is much finer feeling than the 12k. I'm not sure if Shapton has a quality control issue going on, or if maybe I did something to make the 12k feel coarser than it should, but I'm definitely happier with the 8k results. Got it to lop off free hanging hair right off the hone with ease, and just a couple of passes on the strop to follow and it shaves very comfortably--not quite as close as I'd like but I suspect that's more to do with technique and shaving prep as I'm new to straight razor shaving and still using a cheap cream.

 

[eKretz]

Yeah, the Shaptons are a bit novel in the fact that they're "ceramic whetstones" and not your typical waterstones, so that might have some differences up at that grit range. Even within their own grit range, I've seen many suggest that some grits are more suited to carbon or stainless steel than others.

There is nothing novel about that. Generally almost every synthetic hone made is a "ceramic whetstone." Aluminum oxide (India) is a ceramic. Silicon Carbide is a ceramic. Shapton uses a mix of both abrasives as far as I'm aware. Some Shapton hones may only have one or the other, some have both. I think it's the binder type and mix ratio of abrasive to binder that makes them unique. As John alluded to above, there is a lot more going on than just abrasive type.

And I'm going to fall in with the crew that generally isn't in love with the Shapton 12k/15k. It is okay if you go easy and limit its use, but it cuts fast and tends to quickly raise a bit of a wire edge in my experience. It helps to knock the surface back a bit (finer lap) so it's not so aggressive.

 

[Dundee]

It helps to knock the surface back a bit (finer lap) so it's not so aggressive.

Yeah I was lapping it against the 5k. The surface finish from the factory was extremely rough. I couldn't get a mirror finish off of it until after I lapped. It would actually leave a rougher finish than the 5k.

Makes me wonder what their 30k hone would do.

 

[ables]

I have both Shapton 5K and 12K also. My 5K has been almost perfect since the day I got it, real worker for me. My 12k however had lots of bumpiness and 'anti-chamfered' edges, as in the edges 1-2mm in were the highest-roughest points of contact. The first time i used it after a light lap it turned grey very fast and I negatively impacted my razor sharpness. I like OP was a bit shocked.

But after quite a bit of progressive lapping against other stones, starting with 1000grit up to 8000, and sharpening kitchen knifes a few times. Ive got a really nice stone that does improve my 5k shapton and 8k norton edges. I have shaved with it but prefer to then go to a natural stone finisher.