Josh,

I just noticed the link to the book page from Google Books I posted before was not working. So here is a retry: The Perfect Edge: The Ultimate Guide to Sharpening for Woodworkers. The folder on the Nagura stone contains some information regarding your question.

Obviously I'm not the expert here. Just pointing to some interesting material.

Tom, have you got a clue why stones that require water seem to wear faster? (Or is it a wrong observation?) My el cheapo stones that require almost constant soaking/keeping wet wear down very fast, whereas the Wicked Edge ceramic stones don't seem to abrade at all. Does the water cause the wearing down (e.g., due to dissolving the resin bond), or is the wearing down the reason you want to add water (to create the slurry and remove the swarf)? Or do we need Ken to answer this question?

Ken, where are you? Come back! (You have got an unread PM, by the way. The notification is rather obfuscated, but you can access it by clicking on the link in the top right corner.)

I'd say it is a correct generalization when you throw in the sheer number of "el cheapo" stones on the market

But Shaptons and Choseras are in a class of their own on the high end, and are designed to hold up longer while cutting faster, so I think you'd be wrong in this specific case.

Overall, I think wear rates are more dependent on the binding agent/matrix hardness. Ceramic stones like the WEPS ceramic and the Shaptons use a ceramic binder which holds the abrasives in place better and longer. Choseras use a Magnesia bond, which is a little softer and more "cushy" (hence the wonderful feedback).

In theory, by using water the wear rate is increased overall because the abrasion rate is increased as you are flushing the system of swarf, which is in contrast to stones used dry, which "loads up" the surface, slowing abrasion, thus slowing the wear rate down.

Hey Tom, the picture is getting clearer and clearer!



What occurs to me is that the WEPS ceramic stones and the Shapton stones seem very similar. Both use aluminium oxide with a ceramic bond, both are hardly porous and very slow wearing.

Are there any major differences between them? Why is it that the Shaptons require some water (but only a little bit) and the WEPS ceramics stones don’t (although a little bit of water might help)?

And now I am going to use my Chosera stones for the first time .

I feel the WEPS ceramics have a softer matrix than the Shaptons, overall. This makes sense because you want the ceramic to be able to come loose on the WEPS ceramics, but the Shapton mentality is to keep on abrading at every level.

In other news, I will be making some lapping videos with my WEPS Shaptons and Choseras this weekend. Keep an eye on my Youtube channel!

That is interesting, Tom! After three months of use I am not able to observe any wear on my WEPS ceramic stones. So the Shaptons will show even less wear? (Though I am not quite sure what you mean by "you want the ceramic to be able to come loose on the WEPS ceramics". The abrasive ceramic stays right where it is on my WEPS ceramic stones.)

And have you got any clue why the recommendation for the Shaptons is to use a some water and for the WEPS ceramics is to use them dry? Is that something about the way the stones are constructed or is it more like the "cleaning philosophy" behind the stones? (The WEPS stones can be used dry, but they do collect steel dust and require frequent cleaning.)

Subscribed! It's like Youporn, but your social environment won't complain .

I did an interesting discovery during the last few days. When you add a little bit of water to the WEPS ceramic stones, the edge seems to come out much clearer than when you use no water! You don't need to soak the stones: just a few drops of water to keep the stones wet are enough.

The edge even approaches the mirror you normally only get after the 5K/10K Choseras or after stropping with the WEPS stropping pastes.

I was wondering whether anyone has any ideas on why the is the case.

It might seem an obvious case of "facts fit theory". The theory here is that by keeping the stones wet, you prevent clogging the stones with metal filings. This prevents the filings to scratch the edge and makes the stones more effective.

However, I doubt whether this theory holds. The reason is that the stones get just as black when you use them with water as when you use them without water. So apparently steel filings are still accumulating in/on the stone. Or am I misinterpreting this?

Is there anyone who can shed more light on this?

I can't speak yet to why it works so well to use water with the ceramics, but I can attest to Mark's results; I get tremendous results by keeping the ceramic stones wet. I use a spray bottle with water and a few drops of dish soap and get great results - essentially a mirror polish. After the ceramics, a few strokes with the strops and the edges gleam beautifully. Here are the Kershaw blades I just completed with that exact method:









mark76 wrote:

Ytreich from the Knife Forums hits the nail on the head, IMO:



I've also witnessed this in person. Basically, the ceramic loads up with metal flakes, and those flakes stick out like cactus needles, adding stray divots to the surface of the edge. This is somewhat similar to metal burnishing, but its overall coarseness makes it less desirable at the WEPS 1200/1600 level of refinement. We've seen that than on higher grits, metal burnishing can be more beneficial.

Don't forget the flip side - if you let the ceramics load up, they do leave a more refined edge, even if it is less perfect.

jendeindustries wrote:


How do you recognize that the ceramic loads up with the metal?

The point is, when I use the WEPS ceramics with water, the stones do not come out cleaner than when I use them without water. In both cases, there is a little bit of black stuff (metal, I assume) that remains on the stones.

There will always be some residual "black" metal swarf on the ceramic stones/steel That's part of abrading. I think the water helps keep it from accumulating to the point where it begins to burnish the metal instead of abrading into it.