Thread: My CNAT Lapping Journey

Originally Posted by malaverdiere

Just making sure I got this right... Here's how I'd accomplish that. (I'm tempted to go for Euclid's suggestion, but I will try to do with what I have right now)
For finishing the 'slurry' side, I just keep rubbing with the 400 side sandpaper until even.
For finishing the 'burnished' side, I rub with the 400 side sandpaper until even. Then use my small 600 and then 1000 diamond hones (but not much, so that I don't un-flatten it). Then rub with the flat part of a chisel.
And use a permanent marker on a rough side to indicate which side is which one

Just need the 600 and 1K enough to get rid of the 400 grit scratches. But thats pretty much it.

Originally Posted by malaverdiere

Just making sure I got this right... Here's how I'd accomplish that. (I'm tempted to go for Euclid's suggestion, but I will try to do with what I have right now)
For finishing the 'slurry' side, I just keep rubbing with the 400 side sandpaper until even.
For finishing the 'burnished' side, I rub with the 400 side sandpaper until even. Then use my small 600 and then 1000 diamond hones (but not much, so that I don't un-flatten it). Then rub with the flat part of a chisel.
And use a permanent marker on a rough side to indicate which side is which one

I think you got it just right! I would get up to 1K and FLAT on both sides first.... then burnish one side with chisels, a hard nagura used dry, a hard high grit stone dry, and/or my favorite way: hone some chinese cleaver/chef knifes and make them stupid sharp. Then burnish with a hard stone(coticule, hard arkansas, hard carborundum barber hone etc...you get the point). That will do it. The slurry side needs nothing beyong getting it flat up to 1k. The rubing/nagura stone you use will take care of the rest.

Hint: a decent japanese awasedo tomonagura works BEST to finish (before going to water only side), if you got one....as they break down to smaller flakes, and gets the edge to higher grits, otherwise a thuri nagura works well too, and smooths the edge, up to its grit level, whatever that happens to be. The cnat nagura makes the stone behave as a midrange one, 6-8k, as the slurry does not break, but you can use that if midrange work is needed!

And use a permanent marker on a rough side to indicate which side is which one [/QUOTE]

No need to put any marker on the honing surface, just put an arrow on the side pointing towards the burnished side. Or just bevel/flatten the corners a bit more on the burnished side for a visual cue.

Originally Posted by fxt913

No need to put any marker on the honing surface, just put an arrow on the side pointing towards the burnished side. Or just bevel/flatten the corners a bit more on the burnished side for a visual cue.

Good point. I round the edges of the burnished side of my stones. The side I leave a little roughed up just gets an angular bevel.

Originally Posted by fxt913

I think you got it just right! I would get up to 1K and FLAT on both sides first.... then burnish one side with chisels, a hard nagura used dry, a hard high grit stone dry, and/or my favorite way: hone some chinese cleaver/chef knifes and make them stupid sharp. Then burnish with a hard stone(coticule, hard arkansas, hard carborundum barber hone etc...you get the point). That will do it. The slurry side needs nothing beyong getting it flat up to 1k. The rubing/nagura stone you use will take care of the rest.

Hint: a decent japanese awasedo tomonagura works BEST to finish (before going to water only side), if you got one....as they break down to smaller flakes, and gets the edge to higher grits, otherwise a thuri nagura works well too, and smooths the edge, up to its grit level, whatever that happens to be. The cnat nagura makes the stone behave as a midrange one, 6-8k, as the slurry does not break, but you can use that if midrange work is needed!

That sounds a bit overkill (and expensive, and tempting - but that is another problem).

So I used the sandpaper on a ceramic tile again, and got a nice flat surface.

The I usedy small 600 and 1000 diamond and got lots of scratches. Then I used the back of a small chisel. And there are many scratches left. Did I degrade my lapping job by any chance?

I would have stuck to the sand paper and not used the diamond plates on the stone. At least not on the surface I was intent on burnishing. Diamonds tend to cut fast because they also cut fairly deep. So I might do the initial flattening with a diamond plate, but after that I transition to sand paper and let that do the rest of the work.

Originally Posted by Marshal

I would have stuck to the sand paper and not used the diamond plates on the stone. At least not on the surface I was intent on burnishing. Diamonds tend to cut fast because they also cut fairly deep. So I might do the initial flattening with a diamond plate, but after that I transition to sand paper and let that do the rest of the work.

So I can go back to the sand paper to remove the scratches. Then I could use my small AlOx hones from the Lansky set (600 and 1000) to finish the burnishing?

I'd hold off on the burnishing for now. If your scratches are relatively small and in the direction of honing, it should still cut finely.

I've had the best luck with those boxes in terms of cnats - it suggests that the stone originated from woodwell tool (mujingfang) and all of the ones I've gotten will not release particles without you wanting to. That's important.

If a cnat gets a little slow, it's fine to use a little pressure on it like you would an ark, it won't hurt an edge. A little means that you're mindful not to flex the razor and alter geometry, but you don't have to let the weight of the razor go back and forth on those stones 500 times.

For anyone else who gets one of the 8x3 stones, if one of the sides is a little high, you can just hit it with a diamond hone until you have a workable patch. If the last 1/2 inch of the edges is low in some areas, it's not a big deal, the stone will finish the same.

Originally Posted by malaverdiere

So I can go back to the sand paper to remove the scratches. Then I could use my small AlOx hones from the Lansky set (600 and 1000) to finish the burnishing?

If you use sand paper to get it scratch free, going back to the AlOx hones is likely to just scratch it up again rather than burnish it. Typically I'll use sand paper up to 2K grit, then use my Norton 4K and 8K hones. After that if I want a finer surface I'll either polish the stone with CrOx, burnish it with the tomo nagura that came with my Jnat, or find a hard steel tool that I can use to scrub the surface and burnish it even finer. Honestly after the 2K sand paper you can probably skip right to any of the burnishing steps if that's what you're trying to accomplish with your stone, I just have fun playing with them and once they're flat and scratch free the rest of the polishing phases go by pretty quickly.