Ultra fine ceramic stone produces sharper edge than 6000 grit water stone

[Stewie Simpson]

I just placed an order for this product. http://www.workshopheaven.com/tools/...te.html#SID=48


100% pure chromium oxide mixed with a little oil to make the ultimate strop paste.

Rather than removing metal, stropping with chromium oxide smooths, polishes and refines the cutting edge; not unlike the effect water has on clay.

Chromium Oxide (Cr2O3 ) is a superfine, 0.3 micron, polycrystalline abrasive, it is the mineral that gives green polishing compound it’s colour. Most polishing compositions also include other minerals, but for purists like straight razor users, only the best will do.

For most people this 50 gram tub will be a lifetime’s supply.

[Robert Engel]

I'm not sure if the Spyderco is actually finer,or just harder,which causes it in effect to have a finer surface. But,the Spyderco will out sharpen the 6000 grit water stone. And,I haven't even gotten rid of the somewhat "toothed" feeling surface of the UF stone as cut at the factory. Ceramic stones being so hard,it will take some time to finally wear off the fine grinding marks on the surface of the UF stone.

And the point is???

Real world: if its fine enough to shave that's good enough.......I stop with 8K water stone.

[george wilson]

Just basic info to not waste your money on the 6000 King stone. The ceramic UF stone will produce a shaving edge. The King will not.

I agree: a shaving edge is good enough.

When I was a teenager,and had no money,I'd sharpen my 50 cent chisel(new price!) on a cheap,gray hardware stone. Then,I'd strop the chisel for a LONG time on paper,till it would be quite sharp. If you're determined enough,a lot of things can be made to work.

[Stewie Simpson]

Aluminum oxide fused with chrome oxide is a pink abrasive that is used in grinding applications that require slightly more toughness than white fused aluminum oxide. The chrome oxide component of the abrasive enhances its grinding capacity. Although friable and cool cutting, aluminum oxide fused with chrome oxide exhibits strong form-holding characteristics. It is used for precision, broad surface and tool room grinding on hard alloy steels.

http://americanmachinist.com/feature...bout-abrasives

[Stewie Simpson]

The reason I posted the information provided;

I have recently extended my water stone media up to 12000 grit. To achieve an even greater level of polish on the cutting edge of my tools, I wanted to make sure that the Veritas Honing compound I have in my workshop, was able to provide me with that benefit. After further research, I reached a personal conclusion that the use of the Veritas compound after the 12000 grit stone, would actually degrade the level of polish I am already achieving with the 12,000 grit. What others choose to do with this information, is clearly a choice they need to make. In my own case, I have chosen to trial a different product.

[Pat Barry]

The reason I posted the information provided;

I have recently extended my water stone media up to 12000 grit. To achieve an even greater level of polish on the cutting edge of my tools, I wanted to make sure that the Veritas Honing compound I have in my workshop, was able to provide me with that benefit. After further research, I reached a personal conclusion that the use of the Veritas compound after the 12000 grit stone, would actually degrade the level of polish I am already achieving with the 12,000 grit. What others choose to do with this information, is clearly a choice they need to make. In my own case, I have chosen to trial a different product.

Stewie, when you say 12000 grit stone is that equivalent to 12000 grit sandpaper? My guess is no as I have never seen or heard of 12000 grit sandpaper. I'd guess that the particle size for 12000 grit stone would be on the order of a couple microns in size.

[Stewie Simpson]

Pat; I am referring to a 12000 grit water stone.

[Pat Barry]

Pat; I am referring to a 12000 grit water stone.

Yes, I understand that. What I am asking is what is the particle size in your 12000 grit stone. Typically, the size is determined through a sieving process. Things go through one mesh size sieve and are blocked by another therefore giving a grit range of sizes in beteen the two sieve sizes. Do you think the 12000 grit refers to this? If so, then the average particle size might be a couple microns with a rnge up to maybe 10 microns, or do you think the 12000 refers to the maximum particle size in which case the particels would be about 2 microns maximum?

[Patrick Chase]

Thanks Patrick. Yeah, I follow your math and you're right about the financial trade. But I just plain like that 500. It cuts very well. Nothing wrong with scary sharp either, except that I have to change paper, which is a bother.

Fred

Yeah, I got a 500 early on and noticed right away that it's an unusually smooth- and fast-cutting stone, particularly compared to other Shaptons. It also does better on difficult alloys than most other Shaptons. The catch is that both of those benefits stem from it being unusually soft for a Shapton, and that combined with its high cost ($8.50 per mm of abrasive at Amazon prices) makes it a rather expensive stone to use.

If you like that softer feel and faster speed and don't mind flattening, then you might consider the Sigma 3F 700. It's softer than the Shapton 500, and uses Silicon Carbide abrasive instead of Aluminum Oxide. SiC is significantly harder than Al-Oxide (or Alumina-ceramic as in Spydercos), and that plus the friability of the binder means that it will quickly cut any steel within reason (high-Vanadium being the exception). The result is a blazing fast stone with nice feedback. It's 50 mm thick and costs about $1.15 per mm thickness, which makes it reasonably economical.

The Cerax 320 is also a nice basic soft Al-Oxide ceramic stone, 50 mm thick for about $50 ($1 per mm).

The Bester/Beston stones also have nice feel.

[Patrick Chase]

Yes, I understand that. What I am asking is what is the particle size in your 12000 grit stone. Typically, the size is determined through a sieving process. Things go through one mesh size sieve and are blocked by another therefore giving a grit range of sizes in beteen the two sieve sizes. Do you think the 12000 grit refers to this? If so, then the average particle size might be a couple microns with a rnge up to maybe 10 microns, or do you think the 12000 refers to the maximum particle size in which case the particels would be about 2 microns maximum?

Based on previous threads I believe it's a 12000 grit natural stone (though not a JNat), so the abrasive wasn't graded as you describe. Also natural stones are SiO4 (Quartz) which is soft and breaks down quickly, so the relationship between particle size and final scratch pattern may be a bit different than for a synthetic stone.

With that said, #12000 would be 1 um or a bit less in most water stone manufacturers' systems (rule of thumb: particle_size*grit = 10000-12000, 15000 for Shapton). That's down in the "sub-sieve" range BTW.

I find it very believable that a 12K stone would leave a finer finish than the LV green compound, as I've had similar experiences and many others have reported the same. As always the real question is: How fine does it really need to be for woodworking?

[Stewie Simpson]

0.3 micron http://www.workshopheaven.com/tools/...te.html#SID=48

The following site is a Micron to Grit Size Converter. http://www.rahulgladwin.com/docs/mic...conversion.php

Entering the value of 0.3 micron;

(grit size equivalent) = 80,930.38

[Stewie Simpson]

The largest particle size in the green honing rouge bars is 300 mesh. (169 times greater than .5 microns.) = 84.5 micron.

-300 mesh indicates that each particle is .003333 inches or smaller, which leaves the largest particle that would pass through a 300 mesh screen 169 times larger than .5 microns.

http://straightrazorplace.com/honing...-bars-not.html

[Patrick Chase]

0.3 micron http://www.workshopheaven.com/tools/...te.html#SID=48

The following site is a Micron to Grit Size Converter. http://www.rahulgladwin.com/docs/mic...conversion.php

Entering the value of 0.3 micron;

(grit size equivalent) = 80,930.38

There are multiple rating systems for grit. The JIS system that's used by most waterstone manufacturers (notable exceptions: Shapton, Norton) is roughly grit = 10000/diameter_in_microns. For example, the Imanishi 8K stone is 1.2 um (10000/8000 = 1.25) and the Sigma 13K is 0.75 um (10000/13000 = 0.77). By that system 0.3 um is ~33000 grit. Shapton's system is grit = 15000/diameter_in_microns, so they'd rate 0.3 um at #50000. FEPA is somewhere in between, though it doesn't go that high.

It's actually more complicated than that, for example the JIS system constrains the distribution at 4 percentiles IIRC, whereas I only dealt with the nominal/average diameter above. And then there are "slivers" and "plates" to consider, though I don't think JIS constrains those - the ANSI micron grading spec for diamond compounds does.

[Patrick Chase]

The largest particle size in the green honing rouge bars is 300 mesh. (169 times greater than .5 microns.) = 84.5 micron.

http://straightrazorplace.com/honing...-bars-not.html

Three remarks:

1. It's important here to distinguish maximum and nominal sizes. The "0.3 um" for your pure Cr-Oxide paste is a nominal, and it very likely contains particles significantly larger (and smaller) than that. The product page doesn't specify distribution constraints, so there's no way to tell how high it goes. As an example, the ANSI grading spec for diamond compounds allows 1.5 um maximum particle size in a nominally "0.5 um" product.

2. The callout in the spec for the Alumina in the LV compound is an upper limit, not an nominal - "each particle is 0.00333 inches or smaller". You therefore can't directly compare that to the "0.3 um" nominal for your paste.

3. I've used the LV compound, and I've used plenty of 60+ um Alumina abrasives. The scratch patterns from the two are VERY different. While the spec may theoretically allow 84.5 um particles, there weren't really any such particles in the bars I've used. No reasonable amount of break-in or "receding into the strop" could hide the effects of even a single particle that big - it would leave monstrous scratches in its wake. The LV compound simply doesn't do that.

Reiterating something I said above, I'm not a huge fan of the LV compound, and I really do think that you can get better results with a fine-grit waterstone like your 12K and that your observation is both expected and valid. I also think we have to be careful not to overdo it with the negativity though. It isn't anywhere near as bad as that "300-" number suggests it could be, and some very good woodworkers get great results using it.

[Stewie Simpson]

Patrick; the main lesson from this discussion, is that from a buyers perspective, we will continue to be at the mercy of the retailer, and manufacturer, to accurately describe the range of micron sizing contained within these polishing compounds.

Stewie;