Japanese natural waterstones

[CLiver]

Hi fellow woodworkers, I use man-made waterstones (800, 1000, 4000 and 8000) since five years and I am fully satisfied. Two months ago, I acquired a Honyama grade A natural finishing waterstone from Lee Valley. I though I could achieve a mirror polish on my japanese handplanes with this stone. I make a slurry with the nagura stone as I do with the 8000 stone. Curiously, I cannot obtain a better polish than with my 4000 stone. In fact, I get a slightly better surface than with the 1000 stone.

Do you think this is normal given this stone is grade A?

Thanks, Claude

[Steve Knight]

you don't always get a mirror polish with waterstones. a mirror polish does not mean sharp. nothing wrong with lee valley but if your after natural waterstones you should go to a japanese store. like

or

[CLiver]

Hi Steve, A mirror polish does not mean sharp? I understand that what seems a mirror surface to the naked eye is in fact a surface with abrasion marks too small to be seen. If both sides of a blade show a mirror surface, the blade should be sharp. I know that you have a great experience in sharpening japanese blades for your excellent palnes. My point is that I am surprized to be unable to obtain a better finish with this naturel finishing stone than with a 2000 man-made stone.

Thanks,

Claude

"Steve Knight" a écrit dans le message de news: [e-mail]...

[Larry Blanchard]

Not if they're parallel surfaces :-).

[Steve Knight]

a mirror means the metal is shiny (G) before I got shapton stones my blades were not shiny but just as sharp. You can get real shiny with stropping but you won;t have as sharp of edge if you use a good fine waterstone or oilstone. the media is what seems to give a shine or not. but so far I have found if you use the right grits to sharpen you get the same edge with different media but you may not get the polish. the tool will only get so sharp and that's it no matter how fine of grit you go to.

natural japanese stones are getting pretty rare and are not as good of quality as they used to be. so the stone may just not be up to the job. that's hard to say without trying it. I only used a natural stone in a medium grit so I could not say how they finish. but I don't see a better edge from the cloudy one I got with a 8000 from japan woodworker and the shiny mirror surface I get from a shapton. sandpaper tends to give a shine too.

[Manny]

You won't get a mirror finish with natural stones. They leave a "mat" finish. I usually go from my 5000 man made ceramic to the natural for a final hone. If I'm reading this correctly, you feel that because of the "finish" you're seeing, you think the natural stone is taking you back a step. Sorta like the natural stone is around 2000 grit. I usually grade my naturals on how fine an edge I get, through trying them on several of my blades. It's all subjective, but I check the sharpness coming off my 5000, then off the naturals by seeing how easily I can take shave off my fingernail. The natural stone edge takes the least effort. I can also tell while pulling the plane. Waterstones are a different animal since there's no consistent rating system. At least I've never seen consistency. That's why I prefer to try natural stones before buying. I have a feeling that "try before you buy" is the way it was traditionally done in Japan. The person I used to buy my stones from would ask what type of stone I was looking for, pull out a bunch of stones and a bucket of water. I'd hone my blades til I found the stone(s) I wanted. This guy was a transplant from Japan who set up an import business in California.

[Robin Lee]

...as you would get with a "Blanchard" grinder???? :)

[CLiver]

Thanks Manny. I'm not sure that Robin would let me try his stones before buying. ;-) I will continue to explore the question and to try different blades with this stone. Toshio Odate says that natural stones give different results with different blades. Claude

[Layne]

Listen to Steve on this one as it's true. You'll get a mirror finish on lower grit sandpaper sooner than with a higher grit waterstone but, the matte finish on the higher grit waterstone is sharper. I've noticed this while re-establishing the bevel of my plane blades using sandpaper. The bevel would start taking a mirror shine after 600 grit sandpaper, but wasn't as sharp as the 1000 grit waterstone which left a matte finish. I suspect that the slurry and the dulling sandpaper tended to polish the surface more without really sharpening the edge appreciably.

Layne

[Layne]

I used to watch a program called Soka Ga Shiritai back in Hawaii. It was a magazine show. Once they profiled a man who sole trade was making and selling natural waterstones. It was a one-man shop and every day he'd go out on his bicycle, it's basket filled with stones and he'd go door to door selling his stones in the local town.

FWIW, the best sushi chefs are purists when it comes to sharpen>system. At least I've never seen consistency. That's why I prefer to

[Young_carpenter]

something that wasn't mentioned. (my late 2c) is that with Natural Waterstones the "pureness" (every grain actually that grit designation) of the grit cannot be controlled like it can in a man made Waterstone.

[Andy Dingley]

I don't use my natural stones for sharpening woodworking tools, just man-made.

But for polishing swords, where you're after the visible surface effect, particularly in highlighting the different grain structures of the steel, then naturals are essential.