Shapton Pro 2K, 5K or neither?

W

wetdog1911

Joined
Sep 29, 2002
Messages
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I have a Shapton Pro 1K and a AOTO natural blue stone. I recently sold my Shapton Pro 8K after deciding it was a bit too fine for my purposes since I don't have any Japanese knives just yet.

My question is, after the Aoto would a 2k or 5k make any sense, or would the Aoto be enough?

Besides my EDC, most of the knives are for kitchen use and do more slicing than push cuts. I've gotten super sharp polished edges that wouldn't slice a tomato for squat and a rougher edge done with a lower grit that sailed right through.

How close are the 2k and 5k to each other? I've heard very close, but I don't know this for a fact.

Should the Aoto be a finish stone with something between it an the 1k? Or finer, using that as the finish stone?

Thanks!

Rob
 
The 1k is about 15 microns, the 2k is 7.35 microns and the 5k is 2.94 microns. IMHO, the Shapton 2k is the best stone they make and it really removes the scratches from the 1k (which actually seems to grind more like an 800 grit). You would use it in place of the aoto (the aoto is fun, but the Shapton 2k is faster and leaves a brighter finish on stainless & tool steels). The 5k is also a decent stone and leaves a nice mirror surface. The 8k isn't a favorite at 1.84 microns as it seems too much like the 5k only slower. I like the Kitayama 8k better, and you can skip it and go to the 12k/15k or 16k glass stone, which are 1.2, .98 and .92 microns respectively, if you want an adamantine mirror surface.

Are you keeping that aoto flat? They are mud stones and on the soft side of medium (the artificial ones are even softer). Sounds like you are rounding your edge on it. You should easily be able to slice tomatos paper thin with a 5k-8k finish. If you have soft steel (Chicago cutlery, Hecknel's, Wusthof etc.) you'll want a harder stone as it will control the shape of the edge better (actually, I use a sharpmaker for my Wushof's and save the stones for my Japanese knives and wood carving tools).
 
Where do those micron numbers come from. In general I would be very skeptical they could be determined to such precision. You should really write up a reference page or post on the stones you have used.

-Cliff
 
Thanks, that was just the info I was looking for. Looks like a 2k will fill the bill quite nicely, especially when I don't want to deal with the mess of the Aoto.

It's flat for sure. I got one of those granite reference plates that Lee reccd and got busy with the Aoto.

My wife said it's going to be my gravestone after I didn't quite get it all the way under the bed when it first arrived and she kicked it. LOL Now, it's tucked away under the gunsafe and her toesies are sort of safe.

I think this set up should last for awhile till my freehand sharpening skills catch up.

Rob
 
Cliff Stamp said:
Where do those micron numbers come from. In general I would be very skeptical they could be determined to such precision. You should really write up a reference page or post on the stones you have used.

-Cliff
Click to expand...

Oh, I am too, the figures are obviously theoretical since grit is usually more ovoid than round, but they are what they are aiming for plus or minus some variance amount. The numbers came from Shapton. I got the numbers from their existing stones and found the conversion formula between their grit and micron sizes and did a little extrapolation for this chart, which shows the grit sizes for Shapton pro and their new glass stone series, as well as hypothetical grits, plus the old and new JIS grit standards (I got those from a Japanese abrasive manufacturer's web site): http://members.cox.net/~yuzuha/jisgrit1.html (You will notice that Norton's grit numbers are a tad higher than they should be, which corresponds with people's reviews of them). There's also cbwx34's handy little comparison chart based on user impressions rather than numbers http://www.knifeforums.com/uploads/1136390328-ShrpnrCmpre4.JPG I have written about several over on foodie forums and in the kitchen section of knife forums, as have several of the other members here.
 
For all who may read this:

Contrary to popular belief (especially here on this forum) a highly polished edge, on a kitchen knife, will fall through (slice cut) any tomato (regardless of ripeness) with little to no effort without crushing it what-so-ever. If you can't achieve this level then it's a matter of technique being used to sharpen - nothing else.



wetdog1911 said:
Besides my EDC, most of the knives are for kitchen use and do more slicing than push cuts. I've gotten super sharp polished edges that wouldn't slice a tomato for squat and a rougher edge done with a lower grit that sailed right through.
Click to expand...


For wetdog:

I would suspect that your edge has been somewhat rounded in the process of polishing. I'd suggest to return to a lower grit and start over with burr formation, removal, followed with polishing through the grits taking your time to ensure that you do not rock the blade. By the time you've gone through an 8000x (or greater) stone you should be able to effortlessly slice cut the ripest of tomatos while maintaining a smile on your face. :)

I promise that once you've got a knife to this level you'll never want to use a toothy edge in the kitchen again.


--Dave--
 
yuzuha, thanks for the references, those tolerances are what I would have expected. cbwx34 rankings are different than what I have seen on the DMT vs Spyderco.

-Cliff
 
I pulled up the chart that Pam referenced... I have revised it some since that one, and I did lower the DMT stones.... in fact they all fall under the med. Spyderco.... which is similar to what you found. A couple of other adjustments were made too... although I wanted to do a few more, and never got around to it... so I didn't repost it.

I tried to make the chart a 'relative comparison'... some of it based on sharpening a knife and looking at it under magnification to see what type of finish was left. Hard to get a perfect fit... the more items I looked at, but I think it's pretty good for its intended purpose. I tried to base it on what the knives looked like, not what the stone felt like. So for example, the UF Spyderco stone you mentioned does leave a pretty smooth finish... but to me, not quite as good as a 5K Shapton stone. But they're close enough that if I wanted a finer finish off the UF... I would go to an 8K Shapton... not the 5K.... if that makes any sense. So in reality, it's not rated that low... having revised the DMT stones might make that a little clearer.

cbw
 
Here is a microscope shot of the Spyderco sharpmaker rods medum on left, fine in center and ultra-fine on the right (note the glazed streak which shows that the sides of the rods are a bit convex and still make a point contact, but the ceramic is so tough that I haven't got the energy to lap them flat even on diamond stones) http://members.cox.net/~yuzuha/spydrod3.jpg (plus some swarf) I've handled all three of the bench stones and they seem to be identical to the rods except for shape.

It is really hard to judge these due to the hardness and tightness of the bond. Being so hard and dense they will act as if they are a finer grit than they really are, but they also glaze very quickly and leave streaks where metal is rubbing on metal and where the stone has uneven contact with the blade. With the UF, you basically wind up with a bunch of smooth streaks but it does come out looking like a streaky and 5k finish and maybe a hair finer than the Lansky sapphire polish stone (which is also so hard it is a pain to lap). A more porous stone with a softer binder would leave a smoother more even surface. Here is a comparison of the Spyderco medium stone ("/" scratches) vs a medium hardness 400 grit oil filled tool and die maker's stone ("\" scratches): http://members.cox.net/~yuzuha/smv400.jpg pretty similar.

Hard to compare them to DMT too since diamond stones leave horrendous scratches from high diamonds until you get them good and broken in so that most all the diamonds are worn to the same level... I did take a 15 year old extra fine Eze Lap stone (that some might consider worn out) and scoped it out too. It left a finish almost identical to my King 1200 grit waterstone except for only a few deeper scratches from a high diamond here and there. So, if the diamond plate is broken in, I'd say the mesh size of it is pretty close to the Japanese waterstone grit size (though you'll still get a few bigger scratches from a stray high-riding diamond or two). A brand new one seems about twice as coarse as it should be, at least to me.
 
yuzuha said:
... they also glaze very quickly and leave streaks where metal is rubbing on metal and where the stone has uneven contact with the blade.
Click to expand...

Thanks for the details, you are basically then seeing a composite of abrasive+smooth steel. I am mainly interested in the sharpness of the edges at different finishes, edge retention would be ideal, but that takes a lot of work.

-Cliff
 
Yeah, that sounds like even more work. I'm inherently lazy so my edge endurance tests are totally subjective and amount to whether something annoys me by getting dull before I feel like sharpening it again (every couple of months I get the urge to spend a relaxing afternoon tweaking a few knives). My interest is mainly in how abrasives work, and their affect on surface finish and smoothness. To me, sharpness is an indirect goal that accidentally takes care of itself when I get two smooth surfaces to intersect cleanly (though curiosity has gotten me to polish a few single edge razor blades to see if I could tweak them up a notch.)

I do occasionally experiment on different steels to see what kind of finish different stones give them and how small an angle they will take and still hold an edge that doesn't fall apart in daily use, and even that seems like too much work (reprofiling D2 or BG-42 has had me wishing I had a belt grinder, though I have no place to put one). Though, I'm not an outdoors type so whittling, contacting a cutting board and slitting an occasional cardboard box is about the worst abuse that my knives see (no gutting dead animals, digging holes in the yard or batoning through 2x4's & concrete blocks), so my edges are more fragile than some people need.
 
D_R_Sharpening said:
For all who may read this:

Contrary to popular belief (especially here on this forum) a highly polished edge, on a kitchen knife, will fall through (slice cut) any tomato (regardless of ripeness) with little to no effort without crushing it what-so-ever. If you can't achieve this level then it's a matter of technique being used to sharpen - nothing else.






For wetdog:

I would suspect that your edge has been somewhat rounded in the process of polishing. I'd suggest to return to a lower grit and start over with burr formation, removal, followed with polishing through the grits taking your time to ensure that you do not rock the blade. By the time you've gone through an 8000x (or greater) stone you should be able to effortlessly slice cut the ripest of tomatos while maintaining a smile on your face. :)

I promise that once you've got a knife to this level you'll never want to use a toothy edge in the kitchen again.


--Dave--
Click to expand...


Dave

I think you're right. Watching myself closely I saw I was raising the spine just a tad at the end of a stroke. Ending up with a highly polished rounded edge. This was more on the strop than anything.

Rob
 
yuzuha said:
Though, I'm not an outdoors type so whittling, contacting a cutting board and slitting an occasional cardboard box is about the worst abuse that my knives see ...
Click to expand...

Generally comments on edge retention don't require significant dedicated work. All you would have to do for example is note when a knife was sharpened and when it needed to be sharpened again. Over time the average uses would stabilize. It just takes a lot longer to get unbiased data without stock work, but there isn't any rush, it isn't like you have a deadline for your next grant, it is just a hobby.

-Cliff
 
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