Nagura stones

[lsstaipei]

hi everyone,I have used natural water stones and medium grit artificial waterstones,and now I'm considering abot 8000# waterstones,but I don't know too much about nagura stones.Are they necessary for sharpening with 8000# waterstones?What's the difference between using and not using one?Thank you for your help.

 

[yuzuha]

On artificial stones or harder natural stones, a nagura helps provide the slurry that many natural stones give. They also provide traction to keep the blade from chirping (sliding without cutting) on a smooth stone. The hard rectangular nagura that come packed with many finishing stones can also be used as a surface conditioner for the stone (help smooth it after lapping or help clean the swarf out of the stone or just restore the cutting action when it begins to glaze a bit). The Kitayama 8000 stone comes with a nagura and if you work the slurry right it will produce a polish equivalent to a 12k+ stone (the particles in the slurry break down and form an even finer grit). A good slurry also helps with burr control... it rides up on top of the edge and also has a slight abrasive action on top the the blade as well and helps grind the burr to dust (mileage may vary with stainless, though it still helps cut down burr formation).

 

[Way-O]

I didn't know about naguras when I decided to order my (man made) waterstones. They store didn't even sell them... My 6000 waterstone tends to clog up a bit, but I've used a half round ceramic file (coarse) to raise more slur by rubbing it on the face of the stone in long end-to-end strokes. Raises a decent slur, to me at least, and the stone doesn't clog. From my experience, a nagura would be nice to have with the upper grit stones. Though I can't compare them to my emergency solution.

 

[yuzuha]

The slurry is formed from the nagura if the stone is harder than it, or from the stone if the nagura is harder than it, so your file method is equivalent to using a hard nagura on a soft stone and is just fine, though perhaps wears down the stone (and file) a trifle faster.

 

[HoB]

Well, part of the reason to use a nagura is, that you can save a lot of money because you can adjust (if you are knowledgeable enough) the performance of the relatively expensive finishing stones by use of different, relatively cheap, naguras. Depending on the Nagura, the Nagura may grind the particles of the stone to a finer grid, it might also mask the particles in the stone to some degree, grading it effectively finer. In most cases you will end up with a higher polish, when using a Nagura, then when not using a Nagura.