Waterstone potential

[HeavyHanded]

I realize that different waterstones are going to result in different quality edges especially when grinding differing steels, but am curious about a very consistent effect I'm seeing. Straight off the stone, my edges are not very "crisp". They have a fairly toothy feel for their grit value, and very little refinement - in this case I'm using King stones at 1200 and 6000, and Norton stones at 1000 and 4000. The 4000 and 6000 can just shave some armhair off the stone, and improve rapidly with some stropping, easily dryshaving facial stubble, and the 6000 can just treetop some leghair. The 1000 and 1200 cannot generally shave any armhair off the stone, but can easily do so, again, with very few passes on the strop, and can just clear some facial stubble. They look fantastic and are entirely burr-free coming off the stone. I've tried them with a slurry, without a slurry, flushing frequently, allowing the swarf to build up a little - pretty much every way I can imagine using them. Tried with edge-leading, edge trailing, fore and aft - again with no real change in results.

I've tried them with 1095, 420HC, Aus8, and a few other of the common steels with the same general results.

I'm wondering how common this result is. I've tried the waterstones off and on for years and this is the result I've been getting every time. It seems like almost a push between the WS and other benchstones in that the waterstone edges need to be stropped to bring out the potential, and the conventional stone edges need to be stropped to remove the burr and clean up the edge.

I do like the edges I get with them, but am concerned I'm missing something elemental that might be robbing me of their potential.

 

[pwet]

i've been using waterstones almost exclusively for years, first a cheap king combo 1K/4K then shapton pros, then naniwas then a mix of both the later plus a few others.

first keep in mind that the grit stated aren't US grits. a 1K JIS stone is roughly a 320grit stone or a hair finer. then at lower grits the bevel will look more messy than with harder stones even if you work with the least slurry possible as medium coarse waterstones free their abrasive almost as you touch them with your blade. it's the free abrasives that makes it look like that, imo. and it's probably also what makes it produce less burr, imo again.

then i've rarely used a 1K edge without doing anything but when i test my kitchen knives i don't go to a finer stone until i can shave cleanly straight from the 1K (shapton pro in my case ... miles ahead king & norton stones and here that's a fact not my opinion) and a clean 5k naniwa (wich will polish brighter than your king 6k, awesome stone) edge can tree top harms hair.

again here i talk about the edges i get on my work knives, ie very high end japanese carbon steel knives, aogami super @ 64+ hrc, shirogami1 wich as 1,3% carbon, aogami2 ..... i very rarely use my waterstone on my EDC knives as my hands are locked to the angles i use on my kitchen knives ( lower than 10/side) and its not suitable for EDC use.

 

[HeavyHanded]

first keep in mind that the grit stated aren't US grits. a 1K JIS stone is roughly a 320grit stone or a hair finer. then at lower grits the bevel will look more messy than with harder stones even if you work with the least slurry possible as medium coarse waterstones free their abrasive almost as you touch them with your blade. it's the free abrasives that makes it look like that, imo. and it's probably also what makes it produce less burr, imo again.

I'm sure of that, and I suspect that's also why I cannot (with my current selection of stones anyway) get finer results straight from the stone. I did a test with some SIC powder (1200 grit) on the fine side of an oil stone and it produced a very waterstone-esque edge - burr free, toothy, visually clean, but unrefined. Your grit translation is even more aggressive than most, I thought the 1000 grit was about 500-600 CAMI and the 4000-6000 should be about 1000grit CAMI. Another factor is that I generally don't bother to test any of my other edges without stropping due to the residual burr. Entirely possible that most of my edges at comparable grit would be equally underwhelming prior to stropping if I could get them as burr-free as the waterstone edges. On the other hand, I can get edges from my diamond stones that are all but burr free and they are much more well rounded cutters straight off the stone (though I still strop them prior to use). I guess the real question is how they all stack up after stropping. Still, I have to believe even with my current stones I might be missing something.

 

[Jason B.]

Stones will make a big difference even with lower grade steels, king stones "work" but it makes things harder for you because you now must make up for the stones shortcomings with skill. My 6k produces a hair splitting, or a few swipes on a strop from it edge at 3x the speed and 1/3 the wear of your king. Hate to put down the classic king stone but they pretty much sit at the bottom of the totem pole.

 

[HeavyHanded]

Stones will make a big difference even with lower grade steels, king stones "work" but it makes things harder for you because you now must make up for the stones shortcomings with skill. My 6k produces a hair splitting, or a few swipes on a strop from it edge at 3x the speed and 1/3 the wear of your king. Hate to put down the classic king stone but they pretty much sit at the bottom of the totem pole.

Understood, but the Norton's as well? Aside from scratch pattern and rate of wear, I'm not seeing any real difference in the basic characteristics of the edge. My 6k King does a nicer job than the 4k Norton in terms of refinement, but both edges absolutely require stropping to make them cut well despite the apparent lack of any kind of burr coming off the stone - is this normal? If I'm hearing you correctly, there's not only a big difference between the better stones and the King brand, but an equally large gap between Norton's and the better stones? That's kind of what I'm trying to figure out, the difference between what these stones are capable of and what I'm seeing, and the overall characteristics of waterstones in general. Is the trade-off for not producing a burr that the very apex is not as crisp as possible and really needs the strop to develop the peak? The variation between your hair-splitting 6k edges and my tree-topping 6k edges could be entirely attributed to differences in technique - can your 6k edges straight off the stone dry-shave some stubble, cleanly shave arm hair etc?

Not that I have a real issue with my results so far, just trying to compare what others impressions/results are relative to my own and get a better understanding of how things work.

 

[pwet]

can your 6k edges straight off the stone dry-shave some stubble, cleanly shave arm hair etc?

like i said again, if i paid full attention to burr chasing alternating sides etc on the 1K wich i rarely do* i can remove a large patch of arm hair cleanly. it will hurt badly on my face but will shave too.

* simply because i never stop there and rely on a hard felt pad to clean the edge inbetween stones and at the end of the session.

 

[Jason B.]

I think your still "getting a feel for it", the grit scale is also a bit confusing for waterstones and I think that's throwing you off a bit too. It will only do you good to compare to around 220 grit, beyond that its too hard and some stones just do what they do in a grit range though they may be given a number.

At 4-6k you should be shaving without issue, push cutting news print, and it won't be comfortable but removing some facial hair with a 6k edge shouldn't be hard. Have you tried stropping with bare leather or newspaper after? Still before stropping though the edge should feel and act razor sharp, sounds like your forming too much burr from pressure and maybe even grinding the edge into the stone. Don't take much, kings are soft.

Next time you use the 6k let the mud build and use stropping strokes to finish. Let the surface dry up a bit too, if you can get it to where the slurry almost starts to dry and clump your golden. To add water just use drops from your finger, 1-3 at a time or you mess up the slurry.

 

[HeavyHanded]

I'll stay with it. Pretty sure I'm not carving into the stone or raising a burr (that would take some real pressure and no water - I can barely raise a burr with the 200 grit Norton). The edges feel quite sharp with just the thumb-o-meter, and draw-cut like champions but simply lack refinement. A few swipes on a strop and they cut quite well. Tree-topping leg hair off of 6000 grit isn't all that shabby. It only required about ten passes/side on some yellow compound to reach that. Am reasonably certain there was no burr before or after stropping, confirmed at 15x visually with good lighting and then lightly scraped some hardwood at a 90 degree angle to see if anything was going to fold or stand up. I don't know of any better test for burr detection.

Quite a jump from barely shaving arm hair to shaving with that few passes. Again, not complaining about my results, but it sounds like I could be doing better with the stone. Also a bit surprised that stropping on a slurry would work better than edge leading on a clean, wet stone or just going to the strop (what is the edge like before you give it that last bit of edge-trailing?). I did try it at one point but didn't notice any improvement. I'll try it again next time I have 'em out.

Thanks
HH

 

[Jason B.]

This is a very basic way to say it but, edge leading causes the edge to run into the abrasive while edge trailing does not.

 

[HeavyHanded]

Interesting stuff, but when doing some waterstone sharpening at work and checking results under 640x coming off the 1000 grit Norton and 1200 King, I noticed metal formations here and there on the edge that looked like solder - shiny blobs that had been ground smooth and clean to the bevel, but weren't part of the clean grind pattern. Wish I had taken a pic, maybe tomorrow nite if I have time. I suspect this is the mystery of the missing waterstone burr - what doesn't get torn off and thrown into the swarf is being smeared back along the bevel by the action of loose abrasives sliding and rolling along the underside of the bevel. These deposits probably have to be removed before the edge can reach full potential. I don't recall seeing these from the 6000 grit King, or the 4000 grit Norton. Of course the 4000 might be doing the same thing only much smaller, and the Kings are a harder stone and can actually raise a burr if pressure is applied -they also hold onto their grit a lot better than the Nortons. Then again, they might be doing the same thing as well only harder to see, since they don't act a whole lot different?

The same knife done up on a cheap diamond stone showed no trace of this condition, and I've never seen it coming off of sandpaper or AlumOx stones either.

When using high RC Japanese steels, the metal is hard enough that these burr formations are probably ground free leaving a much cleaner edge. Also, most folks that are using waterstones seem to be shooting for a high polish as well, they're not going to be aware of lower grit count artifacts like this.

Found a few reviews with the Nortons that match my own - can just shave some arm hair at 4000 and the edge develops rapidly on the 8000 grit stone, so maybe this isn't a technique issue? Could be more of a materials/steel type issue. Then again it could ALWAYS be a technique issue...

HH

 

[Jason B.]

Hard to say without a pic but it sounds like the last stages of burr removal, once the apex is formed at each stage the resulting burr is not left or right but in the center hanging onto the apex waiting to be removed.

Does it look anything like this?

[/IMG]

BTW, here is a shot of a finished 6k edge. My stone is a bit different and works like a polish stone, its often called a 8k. With a thick slurry on yours it would probably be similar.

[/IMG]

 

[HeavyHanded]

Does not look like your first pic, it doesn't look like any of my other close-ups. Here's one at 640 off of a Smith's fine diamond

and the same edge prior to stropping. Even at 160x this edge looked satin smooth and burr-free. Still was a bit surprised to see no burr at 640.

I'll have to try for a pic of the 1000grit waterstone edge, maybe tonight if I get a chance. It literally looks like blobs of solder worked back into the bevel and shined up. Nothing standing up like a wire edge, or leaning side to side - there's no mistaking a burr at that magnification. At first I thought it was some oil or garbage from my rag, but they're stuck to/part of the bevel itself. Less prominent with the King 1200 than the Norton 1000 but still visible all the same. At 160x the edge just looks nice and clean. Pretty sure of what I'm seeing, or at least certain of what its not. Here's an edge done up on 2000 grit sandpaper at same magnification (gotta spend more time getting rid of the deeper scratches).

 

[Jason B.]

It will be interesting to see for sure! Little lost as to what it could be though, smearing of metal is not real common at that grit.

Very clean edges and great pics, that scope shows good detail.

 

[HeavyHanded]

I'll try again and if I can't get good pics, I can at least find out if its a consistent result. Not easy getting those pics - focal range is so tight that you can have to shift focus just to go from the bottom to the top of a scratch from a fine diamond stone. I'd have a lot more pics, but it takes about 20 minutes to set up each one, and they still expect me to do make some money for 'em while I'm at work! You get a much better picture looking through the eye-pieces, as good as the pics are you can see about 20% clearer with your eyes.

Equally interesting is getting a look at stuff you normally cut - fabrics, paper etc. Really gives one some more insight into why certain edge types work better than others on different materials.

 

[Jason B.]

I know the feeling except in my case I must hold the camera, I usually get 1 out of 10 because my heart beat shakes the camera

 

[HeavyHanded]

Well, this thread got me to whip up a small fixture to hold the knife and control angles a bit better. Here's a few pictures - the knife I really saw the "blob effect" on was a 1095 CroVan BK11. These pics are of a carbon Mora ( I couldn't keep grinding away on my Becker for a test).

Soaked the Norton 1000 grit and sharpened the knife as usual. Allowed a bit of swarf to build, nothing crazy as the knife was already sharp - just a few swirls of metal mixed in with the water. I use a fore and aft sharpening stroke. Visually inspected the edge for burrs with a 15x loupe and then took some pics.

First one is at 64x just to show what the bevel looked like - appeared very smooth but with somewhat indistinct grind pattern at 15x and to the naked eye.

Second shot is at 160x - didn't want to jump straight to the higher level without showing the progression. This is the same stretch of edge.

Third is at 640 - this looks pretty haggard. Bits of swarf and I presume some abrasive particles are wedged into the grind troughs and you can now see a bit better the smeared effect here and there where what appears to be metal is pushed back along the bevel. As I said, it was much more pronounced with the 1095CroVan, but this gives a pretty good idea of what I'm talking about.

On to some quick cut tests. The edge as is wouldn't shave arm hair and could cut down through a paper towel or catalog paper only with a draw stroke. Very catchy as one can well imagine from the pics, but not anywhere near as clean as the pics of the unstropped Smith's 700 grit diamond edge. I thought that looked pretty rough, but it could pass some pushcut tests and shave armhair right from the stone.

Last pic is post stropping -

You can still see some garbage left behind, but its hard to believe this is the same edge - I gave it no more than 10 passes/side on some Sears black emery on the rough side of some craft-shop leather scrap and stropped on a plain old belt, another dozen passes/side. Now we're talking, stabbed it into some papertowel and it easily pushcut the length as well as casually crosscutting catalog paper and even could dry-shave the stubble from my cheek and jaw with very little tugging. Much of this I attribute to the aggressive angle on the Mora, but still pretty big difference for very little work. For anyone that hasn't tried stropping this should be a graphic example of why its so useful and well worth learning. This still doesn't answer all my questions, but I'm feeling more and more like I'm not having trouble with the waterstones, that's just how the ones I have get things done. BTW, anyone know offhand what the carbon Mora's RC rating happens to be?

Thanks all,

HH

 

[peppercorn]

Pretty cool HH, those photos tell alot. The last one, after stropping, is really interesting and a dramatic representation of what stropping does to an edge.

 

[Obsessed with Edges]

BTW, anyone know offhand what the carbon Mora's RC rating happens to be?

Thanks all,

HH

From site http://www.ragweedforge.com/SwedishKnifeCatalog.html , regarding the Mora knives' steel:

"Carbon steel blades (1095) are hardened to 58 - 60 on the Rockwell scale, stainless blades to 56 - 58. A speciality of Mora is the laminated carbon blade. This is a three part sandwich, with a core of high carbon steel protected by sides of tough lower carbon steel. The core of the laminated steel blades is 61-62. Normally, I prefer carbon steel over stainless steel, but I have to admit that the Swedish stainless (Sandvik 12C27mod for Eriksson, 12C27 for Frosts) holds an excellent edge. For use around water, especially salt water, it may be the better choice."

 

[THG]

The 1000 and 1200 cannot generally shave any armhair off the stone, but can easily do so, again, with very few passes on the strop, and can just clear some facial stubble.

DMT's EF stones are 1200 grit. I can split coarse hairs off of this stone and definitely shave arm hairs.

 

[Obsessed with Edges]

DMT's EF stones are 1200 grit. I can split coarse hairs off of this stone and definitely shave arm hairs.

HH is referring to waterstones at 1200 grit, which is relatively coarse under that completely different standard. DMT's '1200' won't match up with another standard's '1200'. Maybe not even a close match, either by grit type, size or cutting performance. I think a comparable waterstone, in terms of refinement/polishing performance, would be at a rated grit number quite higher.