Shapton: Sharp vs Shiny

[Ken]

I've been flattening the backs of some chisels using the following stones: Norton Waterstone 220 grit Norton Waterstone 1000 grit Norton Waterstone 4000 grit Shapton Professional Waterstone 8000 grit

After the Norton 4000, the chisel back is perfectly flat and rather polished. Though I can still see scratches by eye and with magnification, the surface is shiny and mirror-like.

After the Shapton 8000, the surface is less shiny, less mirror-like. The scratches seem to be finer than they were after the 4000 Norton, but the surface is more of a satin finish and not mirror shiny.

Just wondering what's going on here.

Thanks, Ken

[Vijay Kumar]

Dont know how Shaptons supposed to be used. For a normal waterstone

6000x or greater, you are supposed to use a Nagura stone and create a slurry on the waterstone surface before using it. Mirror shine guaranteed.

[woodworker88]

No offense, but what is a Nagura stone? Is it some form of polishing compound like rottenstone?

[stoutman]

[Bob in Oregon]

Not sure what its made of but it is a white natural stone that will not only help build up a slurry, but will also "deglaze" the surface of the stone- taking off the stubborn metal redidue left behind to clean the stone off. you should use it several times during a sharpening.

It is possible that you are using too much water on the 8000. Dont soak it, and just squirt a little water on, then use the naugura stone to build up a slightly wet paste. Add just a drip of water when it gets dry. Use the nagura stone and rinse with water again when the stone turns grey from the metal. It should only take a few strokes, maybe half dozen to make an almost perfectly mirrored surface-- when you hear the blade squeak across the stone- its done. You should be able to see your nose hairs.

[George]

The scratches on the Norton are from the previous grit? Seems a truth in sanding.

Shapton's sharper. Duller stones make shinier surfaces.

[J]

Yep. But more like chalk. Very fine.

-j

[arw01]

Shapton does not require a nagura. Very little water, just enough to wash away the abraded particles. My one chisels are shinny enough to count pores when done with the 5000, let alone the 8000.

I suspect an improper technique. Personal experience with the Shaptons vs scary sharp is Shapton is much sharper at 8000 vs SS 2000 which is quite comparable.

Alan