Determine Ceramic Stone Grit?

[scratchedup]

I bought the- Suehiro Debado No. 2000 SNE #1500 stone. It seems very very much harder and finer than 1500 grit. I can not get any slurry or a "burr" on my knives with it.

It feels to me to be 5000 grit or more.

Ideas?

[ken123]

Grit isnt determined by feel. It is typically measured. This is a very common mistake. If you want a critical measure you would do a psd or particle size distribution study giving you both mean particle size and spread as a bell curve. A harder stone tends to release less abrasive. So a 1500 platinum releases a precise particle size - a narrow single spike. You can also use an sem and do manual measures.

I havent used this stone so I may not be helpful. You could compare the stone scratch pattern to cbn on a nanocloth strop using 12 micron cbn. I dont normally carry this grit but if you have the interest, I can get some made for you.

Ken

[d_rap]

Absolutely stones with the same grit size can feel very different, from soft to hard. And you may get very little slurry. Shapton glass stones in that range are a pretty typical example.

Also depending on how dull the knife is it may take quite awhile to get a burr at that high a grit.

What you're experiencing is pretty normal for a 1500. A lot of sharpeners on this forum start lower to apex or get a burr, 400 or lower, depending obviously on a bunch of variables, and I have found that to be very good advice.

[Carlo]

It’s hard to know what you’re looking for aside from a burr. Are you just trying to refresh an edge?

Dependent on your experience level you may not actually be working at the apex of your edge. Try coloring the very edge with sharpie and give it a few passes to see.

[scratchedup]

Thanks all...
I have a lot of knives and less time so its difficult to keep them all sharp. My favorite stones for feel are a Suehiro Cerax 707- 700 grit and a Naniwa Chosera w/ base 3000 grit.
For tune ups or a simple refresh one is too coarse and the other too fine...or so I thought.

So I bought the Debado 1500. Well its seems like it it not really doing much "cutting" and if I refresh with the Chosera 3000 it SEEMS to do a great job?

[Cigarguy]

"SEEMS" - ???

When it comes to sharpness, seems got nothing to do with it. A tool is sharp enough for the job or it is not. Sharpness is not about cutting newspaper but is about cutting what you need. At least you are way ahead of the majority who buy a cheap Walmark knife, never sharpen it and when it quickly become dull, either dispose of it or put up with a blunt tool.

I've observe over the years that sharpening on 400 grit or coarser stone gets immediate quick metal removal. As I move up the grit range this is less and less noticeable but the edge is getting more and more refine, sharper, and cuts better. I use a 10x loupe to observe what the stone and my technique is doing to the edge of the blade.

For me 400 or coarser is setting the bevel, 1000-2000 grit is getting that bevel really sharp, 3000+ grit is refining the sharpness and polishing. How far up the grit range depends on the knife and steel. Few knives are of the quality that benefits beyond 3000. Experience, the steel, and the tool will tell you. Only way to gain experience is to practice, practice, practice, use and observe, practice, practice and practice some more.

[scratchedup]

I'm still can't wrap my head around why when refreshing the same knife on my 1500 stone is very difficult to get any slurry and the 3000 stone I get it right away. Is not the 3000 double the coarseness of the 1500 stone?

Where does the expensive 1500 stone fit in my sharpening "routine"?

[gladius]

I'm still can't wrap my head around why when refreshing the same knife on my 1500 stone is very difficult to get any slurry and the 3000 stone I get it right away. Is not the 3000 double the coarseness of the 1500 stone?

Where does the expensive 1500 stone fit in my sharpening "routine"?

The Debado (I haven't used) may be like some other (Suehiro) stones that do best with a slight slurry to cut well.