Thread: A good polishing stone, for tools and knives - Shapton 2000/4000?

Ah! I thought Shapton Pro was regular whetstone that required soaking, and Shapton Glass only required a spritz, but it seems they're both splash and go.
Knife people seem prefer the Pro range, and I read a lot of woodworkers use them too. In fact, it seems a lot of the high-quality whetstones (shapton, naniwa choosera, etc) don't need soaking. So this simplifies everything. I'll just get the whetstones I want for kitchen knife sharpening and work it out from there...

all of the shapton stones will work fine for woodworking tools.

The only stones that are marginal are those like the kings or the bester 1000 (the bester 1200 is a hard and more aggressive stone - the 1000 is a softer stone that I'd call a "knife stone" where the softer matrix prevents deep scratches on a big bevel).

Roger

I'm going to reply in relation to the kitchen knife sharpening part of your post.

Question: Are your knives made of slightly softer western steel or harder Japanese steel?

Western knives are typically hardened to below Rockwell 60HRC and have a primary bevel angle of around about 18°, depending on the intended use. They are more robust, sharpen quickly but lose lose a keen edge sooner.

Japanese knives are typically hardened to above Rockwell 60HRC and have a bevel angle of about 10-15°, again depending on the intended use. Their primary bevels are wider, the hard steel takes longer to sharpen, but the resulting edges last longer with proper use, but are also more fragile.

Others may have more advice on sharpening Western knives. My experience is primarily with Japanese knives and I will concentrate on those.

With those acute angles on Japanese knives (one of mine even goes down to a primary bevel of about 7.5°, giving an included angle of just 15°) the hard steel edge become very fragile. I counter this by giving them a very fine secondary micro/nano bevel at a slightly higher angle to strengthen the edge.

The added advantage of adding the micro/nano bevel is that it is very narrow and takes very little time to refresh. I rarely rework the primary bevels as the core cutting edge steel is so hard and durable with those micro/nano secondary bevels that they remain very narrow for a very great number of refreshings if that is done on a very high grit stone.

How fine? I suggest at least #8-10,000. My micro/nano edge stone is closer to #20,000. It takes less than a minute to refresh micro/nano edge if you do it regularly enough. Raising a micro burr still applies. A small handheld stone works well for me. Here is a video of me doing that.

Sharpening micro bevel - YouTube

A broken piece of higher grit waterstone (someone here on this forum ended up with some of those) can be used for that or small piece of man made nagura block. I use natural Japanese waterstones myself but that is dangerous territory to get into...

The grit level finish on the primary bevel is more a matter of preferred aesthetics (like Damascus cladding) and irrelevant to the cutting edge performance of the knife if using a micro/nano secondary bevel. Softer stones are preferred my most knife sharpeners for working the primary bevel.

A harder stone can be used on the micro/nano secondary bevel as long as it is no too slow. I'm not into buffing or stropping my knives and stop with my finest stone.

The Japanese don't do secondary bevels on their woodworking blades and that is understandable given the small size of the bevels on their chisels and plane blades. However, the bevels on kitchen knives are more expansive and there is a case for not having to resharpen all of that every time you want to refresh the edge. There is nothing said by Japanese knife makers and sharpeners about secondary bevels. However, every Japanese knife that I have bought, including some top-end hand forged ones, have come with a nano secondary bevel when examined under magnification and a strong light source.

Anyway, that is my experience. You only need to add a fine stone to what you have already to give it a go to see what you reckon.

Thanks for the responses. After a too much rabbit-holing, I did settle on a solution that I think will work for me.

1. A Naniwa Chosera 800 as a workhorse stone for grinding bevels on knives
2. And a better 4000 stone form Morihei Hishiboshi for polishing
3. I got some high quality 3.5mm veg tanned leather, and have made a few large strops on pieces of Vic Ash for the final step

This will be a great setup for my knives. I find that I rarely need a courser grit for knives, as we take good care. I can add a Shapton Glass 500 in future for light repairs if necessary. I know there are lower grits, but my coarsest diamond plate is 300, and I don't want to have to buy another levelling plate if I can avoid it.

This frees up the 4000 King stone that I already to be used in the workshop for tools (after diamond plates and before strops). I can upgrade it later if I see the need. Probably not.

Question: Are your knives made of slightly softer western steel or harder Japanese steel?

Bit of both. I've got some 'standard' carbon single bevel Japanese knives, as well one really nice aogami 1 'super blue steel' knive that is clad with stainless steel. Then, a bunch of 10 year old German knives (Wusthof Classic) with the softer steel.

My basic plan for knives is to first hone the best edge I can possibly... get then maintain the japanese knives with a few strokes on a strop say once a week, and go back to stones every month or two as needed. The German steel I probably use the steel honing rod, as often as possible, as stropping might roll the edge.

I'm hopeful that with these new stones, it will be faster and more intuitive.

I'm tryna avoid the mega fine stones. they're expensive, and I think it's a diminishing returns game. I care most about a sharp, workable edge, that is easy and fast to maintain. I think my setup will gimme that.

Neil - that bevel angle you're talking about its degrees per side, correct? as in 15 total or something for japanese?

I also use both, and also always use either a buffed edge (a shallower microbevel and then buffing) or a plain microbevel - the apex of the euro knives doesn't even hold up at 25 degrees total, but the microbevel below a thin primary bevel makes a better combination of edge holding but lack of wedging (as you're well aware given that you're using it).


Rogerwilco - with the euro knives, it's nice to have something on the coarser side and then a polished steel to maintain, and a finer setup to sharpen the japanese knives directly.

I finish both with the buffer, but the japanese knife benefits less from it than the euros, and all kinds of stuff is debatable when sharpening (if you're intending a german knife to be steeled often, the edge doesn't need to be as strong, because you're going to be constantly re-aligning it with a steel).

Any decent stones will work, though.

I'm not familiar with the second stone you mentioned, but the cho 800 is a good stone about equivalent to a 1000 shapton. The chosera have a very nice feel with a short soak. I used to buy gobs of synthetic stones, but I'm out of the loop now (I also sold japanese natural stones for a little while after fishing them away from barbershop pickers in japan and then grading them based on what they do).

I'll stop on the sharpening talk - what you're mentioning will work just fine. You may already have a polished steel, but if you don't (it doesn't need to be a perfect one - F. Dick sells a plastic handled one for about $30 US here, which would probably mean $50 there - they are the bees knees with euro knives).

Originally Posted by D.W.

You may already have a polished steel, but if you don't (it doesn't need to be a perfect one - F. Dick sells a plastic handled one for about $30 US here, which would probably mean $50 there - they are the bees knees with euro knives).

Yeah, I've got a basic wustie one, had it for yonks. I've got a great habit of steeling the blade before I use it every time. Unfortunately can't say the same for others in the house who use the knives!

same here. My spouse specializes in nicking edges, and using them as a board scraper. She says she doesn't like them to be sharp, but over the years, has stopped complaining (and stopped with the here and there cuts) when they are.

I was vindicated (though there is no admission) about how dangerous sharp knives are when my mother in law caused permanent damage to her finger trying to cut the plastic tamper proof ring off of a milk container with a dull knife. I have no idea how she managed it, but the knife finally did (or didn't?) cut through the ring with enormous force and went straight into the back of her index finger leading to permanent damage even after surgery, and now she has a finger that aches all the time and cannot be bent...

...but no kidding, while sitting at the table rubbing her finger, she gave me a lecture about how I shouldn't sharpen knives when the kids are around.

My daughter is 11 and has never cut herself with one. She has good habits because she hasn't had the opportunity to use dull knives and develop bad ones. As a courtesy, when I sharpen a knife here, I put masking tape around the butt end of the handle so that everyone at least knows that sharpening is recent.

re: the steels, though - it's easy to get a polished one online, but even wusthof and henckels here like to put a serrated steel in the block sets. The alloy in those knives has changed from something more like 440C to 0.5% steel (about half as much carbon) and a softer temper. Mine say 0.5X15crVMo or something like that, which I can only assume means 0.5% carbon and 15% chromium stainless with molybdenum. or it could be Mn. The softer they are, the more they favor steeling with little sharpening.

Older henckel's "ice hardened" (suspected to be cryo treated 440C) are more like mid to upper 50s hardness and can be sharpened so as to hold their apex reasonably well if one doesn't like to steel. All of them only stay sharp (with repeated steeling) as a japanese VG10 knife that sees only stones.

Originally Posted by D.W.

Neil - that bevel angle you're talking about its degrees per side, correct? as in 15 total or something for japanese?

I also use both, and also always use either a buffed edge (a shallower microbevel and then buffing) or a plain microbevel - the apex of the euro knives doesn't even hold up at 25 degrees total, but the microbevel below a thin primary bevel makes a better combination of edge holding but lack of wedging (as you're well aware given that you're using it).

Yes, DW, my thinnest J-knife, a double bevel nakiri, has about a 15° included angle, so approx a 7.5° primary bevel per side... it has a very thin spine to begin with (at about 1.5mm) and even with that and those low angles the bevel width is quite wide at up to 15mm... 3^rd knife from left.

Kobocho on knife rack.JPG

There is no way it would survive at those low angles without its secondary micro bevel. It's a knife for very thin delicate cutting work.

Nakiri bevel and secondary edge - 90rt.jpg

Just clarifying as a beginner might read that. I like those angles, too, and do the same thing - a thin primary with some small edge protection to protect the actual edge is a joy to use.

My straight razors are about 16-18 degrees in general (that's where they all are - any less, and the edge doesn't have enough strength, and any more, they begin to feel blunt or kind of "smooth" without much aggressiveness (sometimes soft or overhard razors need to be stepped up a couple of degrees and they always feel weak compared to a very good crisp razor that needs no help).

I have heard of some fantatics going as low as 10 degrees on the total bevel, but damage moves through the edge up into the bevel very easily like that (straight razors in the hollow may be less than that, but their spine causes a fairly strong microbevel at the spine to edge angle. When they are of good quality and have the very apex worked over a little by a linen, they're a thing of joy, cutting hair smoothly but not cutting the skin on the back side of the pore, and almost completely indifferent to a week old farm of facial hair growth.