Waterstone grit Norton vs Shapton ceramic

[Ricky]

I got a 20 year old Norton combo waterstone.  4k/8K.. I bought a shapton pro kuromaku 12K a year ago.  Was prepping the back of
a new Japanese chisel I bought and working up through the grits. At 8K the Norton gave it a nice mirror polish.  I thought the shapton 12K would
take it to a higher level of polish.  Nope.  Looked a little bit hazier after using it.  I  guess these grit levels aren't standardized.

[hbmcc]

I have no Shaptons, but my stones have migrated to finer grits after "as new". The DMT's were disappointing for the same reason; they just kept going finer. Ceramics can be refreshed.

[Admiral]

I've given up trying to figure out what grits are what after spending a decade or so, and $$, on various media. I've had ceramic, waterstone, diamond, oil, the whole magilla universe. I've settled on just using some flea market oilstones that approximate coarse, medium and fine, and then strop on leather with compound and do a final strop on brown paper bags from the supermarket. Gets things reallly sharp and keeps it simple and easy to get back to work. But as far as grits, I've not a clue.

[OneStaple]

There's a lot of variables that goes into someone like this. I know enough to be dangerous, but there are certainly others that know more.

No, grit levels aren't standardized across manufacturers, and there can be significant variation. That applies to various stones, sand papers, and other sharpening media. There are exceptions, such as when the particle size is specified in microns on a diamond paste, but even then you can have variations on how tightly controlled the particle size distribution is across manufacturers. I'm attaching a chart that I've found helpful to try to compare different sharpening media grits.

There are a lot of other variables though that aren't captured in the chart. The actual sharpening media (e.g., diamond, aluminum oxide, etc) and binder material make a big difference in your overall experience. As a generalization, stones that wear down quickly also tend to expose fresh sharpening media, keeping up a faster/coarser cutting. Ones that wear more slowly tend to allow those particles to break down, giving both a slower sharpening and a finer sharpening for a given grit (until new media is exposed). A diamond plate is kind of the extreme of this. It essentially only has one layer of material. There's a break-in period where those brittle diamonds fracture, making smaller diamonds. Usually you get to a "stable" period with the finer particles that then lasts a long time.

Whether the stone dies a good job creating a slurry (and whether you wash off the slurry) also makes a difference. The slurry essentially becomes broken down particles, allowing an effectively finer sharpening.

Different sharpening media will also react differently to different steels or a given steel at different hardnesses. That can impact sharpening speed and level of polish.

Now, that all being said, I'd still expect a 12k Shapton to give a finer polish than a 8k Norton.

Tyler

[attachment=49173]

[Ricky]

Thanks for the replies gentlemen.  I was doing it over the sink, with frequent flattenings and washing the stones with running water often.
It might have been a fluke, got a couple more chisels to flatten.

[hbmcc]

Lee Valley sent me a pamphlet/advert for their sharpening media a couple years ago, "Sharpening By Hand". Pretty informative. Since the image posted by Tyler is only large enough to read while I am doing this comment, I thought you could use the one on Lee Valleys page. A simple search for grit charts didn't help me.

Go to Tools Section, find the the top bar and click "Tools". The flyout will have Top Categories; under Featured the subtitle "sharpening by Hand" will take you to the pamphlet I refer to. ... Sheeshhh! these jumps are insane!!! ... 

Immediately, is a highlighted block, an index. The bottom reference, Grit Charts, will take you to the gold. The charts reference several grit types LV sells. Stones, diamond, ceramic, oil, and unique. They all include micron sizing, the common denominator. It looks like Ricky's Shapton is finer than his Norton 8k. 

Regardless, it is all informative reading as is typical of LV.

[AHill]

There is so much that affects sharpening performance that it's hard to judge based on any manufacturer's grit size. What exactly does that grit size mean? For many, it's the average size of particles in their sharpening media. That alone does not explain the distribution of particles (smaller than or greater than the published grit), nor how the media breaks down during sharpening (think of the slurry you create). Macro appearance e.g. mirror-like or dull also is not a definitive indicator of how small the abrasive particles are. Unless you can get a microscope or loupe on your edge, or compare how long your edge stays sharp before needing a touch-up, published particle sizes should only be used as a guide. The Grit-o-Matic chart is pretty good, and it's free from their website. It's not clear to me how Lee Valley positions stuff on their chart. If it's just using manufacturer's claims, it might not necessarily provide the kind of information I cite above.

As has been said ad nauseum on this forum, find a system you like that works with the tools you have. A fine oil stone will not be your friend if your edge tools are more modern tool steel alloys. Stones that work well on O-1 may not work well on A2 or D2 steels. I wish Schtoo (Stu Tierney) was still active on this forum. He had a wealth of practical knowledge gained from his expertise in Japanese water stones.

Another closing thought - the binders used in some of the sharpening stones can make a big difference in your sharpening routine. I started 20 years ago with King stones I purchased from Woodcraft. I found the binder to break down quickly, which required more work to keep the stones flat. The stones worked fine, but it simply took longer to work with. Nortons were a great improvement, and Shaptons a notch above that. I currently use Sigma Power Select, which seem to have a sweet spot of being aggressive enough to handle more exotic steels while still maintaining their flatness during a sharpening session.

All that said, the old timers will tell you that standard Arkansas oil stones (or Norton India stones), followed by stropping is perfectly fine for edge tools using vintage steels or O1. And they would be right.

[Ricky]

  Nortons were a great improvement, and Shaptons a notch above that.  I currently use Sigma Power Select, which seem to have a sweet spot of being aggressive enough to handle more exotic steels while still maintaining their flatness during a sharpening session.

All that said, the old timers will tell you that standard Arkansas oil stones (or Norton India stones), followed by stropping is perfectly fine for edge tools using vintage steels or O1.  And they would be right.

I don't have any tools with the modern more exotic steels.  Pretty much old stanleys, LN with 0-1, and some hock 0-1 replacement blades.  And the one Japanese chef knife I splurged on has Aogami 1 carbon steel.  I don't know what that means, but it's my favorite knife.  Takes a very keen edge and holds it, even suffering my wife's mistreatment.   LOL!  I am impressed with how flat this shapton stays.  I prefer the feel I get fom the Nortons but that's just subjective.

[barryvabeach]

Ricky, just wanted to point that years ago someone noted that as he went to finer and finer stones, the back of the chisel approached a mirror surface, then as he went finer still, the back started getting a hazy finish, and IIRC ,  others noted the same thing.  So the haziness may not be an indicator that the stone is coarser.

[ChuckHill]

LV’s SharpenNet has a comparative grit chart by makers, and other information that may be of interest to you