Slurry/nagura for my shapton glass -- questions

Bladenoobie1

Bladenoobie1

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Jul 20, 2012
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Hi,

With my shapton glass waterstones, I have consistently experienced glazing with my 4k stone. I found initially I was using too much pressure but even when reducing my pressure quite a bit, I still get some glazing issues. That aside is there a good resolve to this? Would the addition of a nagura stone help me with this issue or at the least, give me more feedback? If so, what kind of nagura do I get and from where?

- BN
 
To cut the glaze or build up a bit of slurry a diamond pocket stone works great. At that finish I'd recommend using a fine grit.
 
Well I had a DMT aligner but its long since sold. Do you think a chu nagura stone from CKTG would alleviate my issues?
 
I doubt it, get the DMT slurry stone they sell. The GS are very hard and a normal nagura will do nothing.
 
knifenut1013 said:
I doubt it, get the DMT slurry stone they sell. The GS are very hard and a normal nagura will do nothing.
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So with the DMT slurry stone I would just rub it randomly on the glass stone when glaze starts to build up? Or do I use it right before I sharpen?
 
knifenut1013 said:
I doubt it, get the DMT slurry stone they sell. The GS are very hard and a normal nagura will do nothing.
Click to expand...
See, this I'm curious about. The Shapton glass stones are described as ceramic waterstones, yet they aren't treated the same as Spyderco ceramics. From the fact that there is a specific diamond lapping stone for these stones, I would assume that the use of it doesn't change the "grit size" of the stones and doesn't ruin the diamond plate. So I'm kind of wondering what the difference is between the two(Shapton and Spyderco).
 
Noctis3880 said:
See, this I'm curious about. The Shapton glass stones are described as ceramic waterstones, yet they aren't treated the same as Spyderco ceramics. From the fact that there is a specific diamond lapping stone for these stones, I would assume that the use of it doesn't change the "grit size" of the stones and doesn't ruin the diamond plate. So I'm kind of wondering what the difference is between the two(Shapton and Spyderco).
Click to expand...

Well the shaptons are a ceramic abrasive binded by some form of media. With the glass, they're waterstones and as you use them, the ceramic particles break from the matrix exposing new particles of the same size so you can continue to sharpen without the stone clogging up. With the spyderco ceramics, the ceramic is not intended to break from its matrix in addition to the ceramic particles being extremely fine. If you were to lap a spyderco ceramic you would break the surface ceramic particles from the matrix, but at the same time in doing so you would alter the surface finish. The binder in the spyderco ceramics are probably a lot stronger than those in the shapton glass, so the surface finish is likely to be very different than that of the original due to lapping.

So basically the ceramic in the glass is meant to be broken from its matrix and the spyderco ceramic particles aren't. If I said anything incorrect, someone please correct me.
 
What you would be looking for would be a CLEANING stone rather than a nagura. Especially a natural stone nagura like a chu nagura is not what you would use here. Naguras are included in the sharpening slurry, whereas a cleaning stone's grit is not included in the sharpening slurry, but rinsed off.

Specifically for Shapton GlassStones, use more water to have less black metal swarf sticking to the stone. Ceramic is a pretty wide generic term, so as already mentioned, you can't generalize between Spyderco and Shapton ceramics or even ceramic rods. I find that flattening your GlassStone preferably with diamond lapping plates like Atoma and DMT plates also takes care of the embedded metal swarf problem. FWIW putting a comparable grit of CBN on the stone - eg 4 micron CBN on a 4k GS will minimize or eliminate metal swarf buildup as a side effect of increasing the abrasive capability of the GS especially on more abrasion resistant steels.

---
Ken
 
Bladenoobie1 said:
Well the shaptons are a ceramic abrasive binded by some form of media. With the glass, they're waterstones and as you use them, the ceramic particles break from the matrix exposing new particles of the same size so you can continue to sharpen without the stone clogging up. With the spyderco ceramics, the ceramic is not intended to break from its matrix in addition to the ceramic particles being extremely fine. If you were to lap a spyderco ceramic you would break the surface ceramic particles from the matrix, but at the same time in doing so you would alter the surface finish. The binder in the spyderco ceramics are probably a lot stronger than those in the shapton glass, so the surface finish is likely to be very different than that of the original due to lapping.

So basically the ceramic in the glass is meant to be broken from its matrix and the spyderco ceramic particles aren't. If I said anything incorrect, someone please correct me.
Click to expand...
From what I've read, the Spyderco ceramic is sintered, so rather than particles of a specific size, it's more like the entire stone itself is a single abrasive particle, a grit size of 1 if there is such a thing:D. Thus why the "grit size" changes depending on the grit of abrasive you use to lap them.

As for your glazing issue, have you tried using a plastic eraser? I see that one recommended for ceramic rods.
 
I have no issue removing the glazing by lapping the stones on Silicon carbide sandpaper over a granite tile. That isn't the problem. Its more of, during the sharpening process itself. I just saw the dmt slurry stone knifenut was talking about and it looks like a viable option to fix my issue.
 
I'm not 100% sure on how ceramic waterstones are put together, but they are VERY different from a traditional ceramic abrasive like the spyderco stones or similar ceramic hones. It's my understanding that shapton and most other "ceramic" waterstones use a traditional waterstone binder with "engineered" loose ceramic abrasive particles similar to those used in ceramic grinding belts. IIRC the shapton pros are ceramic abrasive particles in a resin binder and the glass stones use a different process.
 
The term ceramic is often related to a specific type of material when it truth its a process.
http://en.m.wikipedia.org/wiki/Ceramic

The fancy PM steels we use in our knives are a "ceramic" by definition yet we still call it steel.

Shapton, chosera, Arashiyama, Nubatama, bester, and many others are all ceramic stones.
 
Magnaminous_G said:
Heheh, I've actually wondered if anyone has ever done this.

On the topic of water, OP, are you "splashing and going," as they say at Shapton?
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I am. It's only on the 4k stone I have this issue, not on the lower grits. I will try out that DMT slurry stone and report back on results.
 
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