Thread: My CNAT Lapping Journey

Originally Posted by fxt913

From what I see you got e really good and hard one. Properly prepared it should provide a great high grit polishing surface. Euclid has presented to you just what you need to make it really flat, then you will need to burnish it. Ideally prepare two surfaces, one burnished, that will serve as your final water only surface, and one that is a bit rougher, as you would use slurry in it, and/or finish knifes in it. Never slurry on the burnished side.

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

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!

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).

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.