Diamond or Ceramic?

[Nathan Johnson]

A sharpening thread...I know, I'm sorry, but paralysis by analysis and I need more internet opinions to confuse me further.

Ultimately, my question is this:
Will I get a better (and more durable?) edge sharpening with Shapton Pro or Glass than I would using diamond stones and stropping?
Maybe that's difficult to quantify?

Currently, I use a two-sided DMT duosharp 600/1200 and then strop, either with green compound on leather, or bare leather, or both. This is a small stone, and the recesses are super irritating on smaller chisels and such, so i want to get a set of stones after doing this for a while.
I have quite a bit of A2 to sharpen, and also PMV11, O1, and whatever Narex calls their metal.

I do not want to soak stones, so the Shaptons, either Pro or Glass are on the radar. But diamond stones would be less maintenance, so that's appealing. (I do have a coarse DMT diasharp already so would not need a flattening stone.)

The internet seems to indicate the Shapton glass stones work a bit better on A2 than the Pros. Maybe this is nonsense?

Anyway, help me spend my money.
A set of DMT stones or a set of Shaptons? Can I get the same edge quality with either, or is ceramic noticeably better?

[Jim Koepke]

Nathan, my comments should be taken for what they are, comments based on opinions or observations garnered from other posts.

In particular the recent post on the Cosman Sharpening method. In this method the work starts on a coarse diamond stone and finishes on a fine Shapton. My extrapolation from this is the water stone is better for finishing than any diamond stone, at least in Rob Cosman's world and apparently in the experience of others.

jtk

[Nathan Johnson]

Nathan, my comments should be taken for what they are, comments based on opinions or observations garnered from other posts.

In particular the recent post on the Cosman Sharpening method. In this method the work starts on a coarse diamond stone and finishes on a fine Shapton. My extrapolation from this is the water stone is better for finishing than any diamond stone, at least in Rob Cosman's world and apparently in the experience of others.

jtk

Yeah, that's kind of where I'm stuck a little bit. How much better is the edge off the 16k stone versus what I'm seeing from diamond/strop. Is it 10% better? 25%? Not noticeable? Impossible to quantify?

[ken hatch]

A sharpening thread...I know, I'm sorry, but paralysis by analysis and I need more internet opinions to confuse me further.

Ultimately, my question is this:
Will I get a better (and more durable?) edge sharpening with Shapton Pro or Glass than I would using diamond stones and stropping?
Maybe that's difficult to quantify?

Currently, I use a two-sided DMT duosharp 600/1200 and then strop, either with green compound on leather, or bare leather, or both. This is a small stone, and the recesses are super irritating on smaller chisels and such, so i want to get a set of stones after doing this for a while.
I have quite a bit of A2 to sharpen, and also PMV11, O1, and whatever Narex calls their metal.

I do not want to soak stones, so the Shaptons, either Pro or Glass are on the radar. But diamond stones would be less maintenance, so that's appealing. (I do have a coarse DMT diasharp already so would not need a flattening stone.)

The internet seems to indicate the Shapton glass stones work a bit better on A2 than the Pros. Maybe this is nonsense?

Anyway, help me spend my money.
A set of DMT stones or a set of Shaptons? Can I get the same edge quality with either, or is ceramic noticeably better?

Nathan,

Neither are good for a durable edge, both will give a sharp edge with impressive "shine" but both systems leave steep sided and relatively deep scratches that are a locus for edge breakdown. One of the internet sharpening posters said something like, if a 16K stone is as fast as a 8K stone then it is a 8K stone no matter what the seller calls it. I expect those words are true. As the old truism goes there is no "free lunch" but there sure is a lot of marketing.

Almost any stone combination will get your cutters sharp, some faster than others, some will shine the steel to a mirror shine some do not, some will give better edge retention. BTW, shine is just for bragging, it has little to do with sharp or edge durability. Depending on the steel the best stones for sharp and durability are natural stones like JNATs or Ark.

Of course as with all things wood, YMMV.

ken

[Frederick Skelly]

I have both dmt and shapton. Over the last year, I find myself buying more shaptons (500 grit, 1000, 6000) and only using my dmt's for only heavy work like nick removal. But sharpening is a pretty personal thing, and this is just what works for me.

I sharpen A2 and O1 on all of them and dont notice a difference with the pros. (Maybe my tastes arent refined enough? )

Instead of buying a set, why not buy a shapton 1000 grit and see if it works for the way you sharpen?

Fred

[Phil Mueller]

Nathan, it often seems like I’m missing or needing something when it comes to sharpening. But, I’ve settled on my highest priorities and lived with the result. I hate the mess of anything that has to be soaked in water or oil, makes a slurry mess, running back and forth from the kitchen or bathroom for water and clean up, and no where to keep the mess in my small shop. Other than touch up on a strop, I’m just not going to go through this every time something needs touching up.

I think it’s best to use whatever set up will be convenient enough to use it often. That’s different for all of us.

I suppose I may be sacrificing some sharpness, but who knows. I moved to diamond stones and a ceramic finish stone with leather strop some time ago. Nothing but a spritz of water and off you go. Doesn’t take much space, minimal mess and gets things pretty darn sharp.

I’m even considering moving to just the two stones in the Cosman method. We’ll see.

[Jim Matthews]

I use a Coarse India and Medium Lily White Arkansas followed by power buffing (instead of a strop).

I do not use a power grinder. If you go with Cosman's method, a power grinder is integral.

I use a #400 Atoma plate to grind and reshape main bevels.

O1 is quickly honed this way.

Variants of PM V-11 take longer on the last two steps as the wire burr is tenacious.

A1 takes forever this way.


I recommend adding a Hard Arkansas stone, instead of a Shapton if you're avoiding water in the shop. Cosman recommends the Bora water additive which seems to inhibit rust formation - but I prefer WD40 as a lubricant.

(Full disclosure - I think I get my best edges from a set of Shapton Pro stones, but can't tolerate the mess.)

[David Bassett]

Nathan, you are struggling with the complexity of sharpening. (Too many options. Too many techniques. Too many opinions.) For a moment take it at its simplest. All you are doing is scratching away the dull bits of steel and then trying to even out those scratches into a smooth(er) surface.

The real complications creep in when you consider some abrasive particles won't scratch ("cut") some steels, or particles of the steels (carbides), well, if at all. With the options you are considering this shouldn't be a problem.

That leaves removing the scratches, which is basically the polish from your final grit. Like sandpaper including intermediate grits will save time on the final step, and sometimes time in total. Cosman's method seems to take the biggest jump, but he is only polishing the tiniest of micro bevels at the very edge so saves time by working very little surface. Lie-Niesen teaches a similar sequence, though with a smaller jump. Others advocate intermediate steps, polishing more surface, etc. The key in this respect is sticking with a single system until you become competent with it.

As far as you specific questions. I don't like the way diamond plates feel, I'd say changing is wise. (DiaSharp sucks less than DuoSharp, those gaps may help when flatten stones, but drive me nuts when sharpening, as you noted.) Also diamond scratches seem "harsher" than you'd get from a synthetic water stone, so going to a higher "grit" may be required to get an equivalent final surface. So switching to stones or adding a higher grit stone after your diamond plates seems to me to meet your goals. The suggestion to get a 1K stone to try is good. Maybe getting a 3K-6K stone to use between your current diamond plate and your strop would solve your major problem and be another way to experiment with stones.

Good luck.

[john zulu]

Ceramic as the bond with diamond will wore down as the adhesive fails over time. I generally use whetstone and I find it fast enough on all steel I am using, A2 to PMV11.

[Jim Koepke]

Yeah, that's kind of where I'm stuck a little bit. How much better is the edge off the 16k stone versus what I'm seeing from diamond/strop. Is it 10% better? 25%? Not noticeable? Impossible to quantify?

This is something that everyone has to determine for themselves.

One first need a way to test sharpness. There are testing units made for this with consumable pieces of something to be cut to determine how much pressure is used to go through the test piece.

Simpler is to use one of the common tests used by other woodworkers. How a blade pushes through paper is one test. A blade has to be extremely sharp to push straight into a piece of paper at 90º. It takes a very sharp blade to penetrate even at lower angles.

Some like to shave arm hair as a test. Some consider this too dangerous. Shaving with a straight razor is also dangerous.

Carvers often check a gouge's blade sharpness by how clean it can cut across face grain.

A chisel or plane blade should be able to pare end grain cleanly in a soft wood like fir or pine:

#65 On End Grain.jpg

The real test of sharpness is if the tool is able to do the job neatly and efficiently:

End Grain Shavings.jpg

Note how the end grain has no separation or voids. A dull blade will tend to push the fibers apart before severing them.

jtk

[Curt Putnam]

IMO, regardless of medium, you want finish at a sub-micron level. LV's green compound is ~0.5 micron. The Sigma 13K stone is about 0.75 micron.
The top 3 DMT Diasharp bench stones are 9, 6, and 3 microns. The 8K stone @ 3 microns is a long way from being < 1 micron. So you are going to need a finishing step with diamond.

Read up on the unicorn method - it might alter your thinking.

[Nathan Johnson]

Fears confirmed: there is no Holy Grail.

Sad face.

(I do appreciate all the input.)

[Christopher Charles]

I'll only add that I have used the shapton ceramics for about 10 years in a shop that freezes frequently. Have the 1000, 5000, 13000(? it is light yellow) set with a diamond plate that Stu used to sell. I bought that set because it was well regarded, met my need for being able to freeze and be splash and go, and has helped keep me out of the sharpening worm holes since. Good luck!

[Rob Luter]

Nathan, my comments should be taken for what they are, comments based on opinions or observations garnered from other posts.

In particular the recent post on the Cosman Sharpening method. In this method the work starts on a coarse diamond stone and finishes on a fine Shapton. My extrapolation from this is the water stone is better for finishing than any diamond stone, at least in Rob Cosman's world and apparently in the experience of others.

jtk

I was the OP on the post Jim references above. An important takeaway for me was that the 1000 grit diamond plate is used to establish only the secondary bevel. I'll be adding an intermediate grit Shapton (4K or 6K) for secondary bevel maintenance. Using the 1K Diamond every time is overkill unless your edge is totally shot.

Yeah, that's kind of where I'm stuck a little bit. How much better is the edge off the 16k stone versus what I'm seeing from diamond/strop. Is it 10% better? 25%? Not noticeable? Impossible to quantify?

I guess it depends how much you strop, or how long you want to strop. The 16K Shapton creates a mirror smooth tertiary bevel in just a few strokes. The same holds true for the back of the plane iron using the ruler trick. I've been very impressed in that regard

IMO, regardless of medium, you want finish at a sub-micron level. LV's green compound is ~0.5 micron. The Sigma 13K stone is about 0.75 micron. The top 3 DMT Diasharp bench stones are 9, 6, and 3 microns. The 8K stone @ 3 microns is a long way from being < 1 micron. So you are going to need a finishing step with diamond.

Read up on the unicorn method - it might alter your thinking.

The 16K Shapton is promoted as being .92 micron and produces an impressively smooth finish. I've also been hitting the edge with a horse butt strop charged with a little Flexcut Gold for a couple strokes as a last step. Does it really make a difference? Who knows? I will say my tools are sharper than they're ever been and I considered myself pretty good at sharpening prior to the change to the Cosman method.

[Andrew Pitonyak]

The internet seems to indicate the Shapton glass stones work a bit better on A2 than the Pros. Maybe this is nonsense?

This is some of what I have in my notes (I have lots of notes).

The Glass series is considered Softer and releases abrasive faster allowing them to cut faster. This is where the density difference comes in, the Glass stones are more dense than the pro stones making them seem harder yet still called "softer" because they wear quicker. (So does the glass dish faster? probably).

GlassStones were developed specifically for the US market based upon experience gained from the Pro Series. GlassStones differ in that they cut more quickly in the tougher steels such as cryogenically treated A2 common in Lie-Nielsen and Hock and Veritas blades. They are also engineered to be more economical by employing a glass base.

Next, I have detailed descriptions for each of the Professional stones, but will not take the space here. For the PRO stones, I own the 5K and the 8K stones. My first shapton was the 5K. I think that Derek Cohen dislikes the feel of the 5K stone.

Next comes my notes specifically on the Glass stones. If I were to paraphrase, yes, this is the better stone for the "high resistance" steels such as PMv11, A1, D1, and A2. Not from my notes, i think that the PRO stones was for the chefs and the glass stones was for the woodworkers. I have a table that lists the different glass stones and which application it is good for, but I have no easy way to create this table here. The chart is also available here:

https://jendeindustries.wpcomstaging...-glass-series/

If you really want a dump of my random thoughts, let me know and I can directly email you a copy of my ramblings on sharpening stones.

Why do some people prefer to NOT finish with diamonds?

(opinion) Because diamonds are reputed to leave deeper scratches so you might have more of a tendency to have fracturing at the edge.

So, why use Diamonds? because they cut fast. Why use something else after? To smooth out those scratches and apparently other things do a better job of smoothing out those scratches.

The Shapton stones are very consistent for grit size.

It was suggested to me that by their nature, Arkansas and Washit stones have a tendency to polish as they cut because of the stuff other than the hard stuff that does the cutting. I believe that an Arkansas tone is greater than 99% Novaculite (Silicon Dioxide) and the specific gravity will tell you how tightly it is packed (I think). An interesting things about the Arkansas stones is that you can strongly the edge that it leaves by lapping the stone on something like loose carbide. I saw a demonstration where one of the finest arkansas stones was rubbed on different sides with different grits (probably silicon carbide) and I think it was 220 vs 600. Same stone and the different sides left different edges. One place was selling Washitas (years ago) with instructions on lapping your Washita on different sides for different edges. I would try it now, but it intimidated me at the time.

With something like a Shapton, you are pretty sure up front what you are getting. That said, I have a couple of Arkansas stones and they work just fine. The real question becomes, how will you "clean up that edge" for the final polish. David Weaver demonstrates going from a Washita to a strop to whisper thin shavings from his hand plane. I am not great with stropping. I should just hang with Steve and have him let me practice with him. I get a pretty amazing edge from my Shapton Glass 15K directly.