Thread: Flattening Chinese 12k

Hi All,

I've just notice that my new (ish) chinese 12k waterstone isn't completely flat. It's not far off, only just detectable when i laid it on a piece of glass, but i'm still obsessive enough to want it perfect!

Question is: what the hell do I use to flatten it? i used wet/dry sandpaper on glass for my norton, but it seems that the chinese 12k would be a lot harder. Or am I wrong?

Has anyone flattened one of these before?

Cheers,
Ian.

Originally Posted by taketwoaspirin

Hi All,

I've just notice that my new (ish) chinese 12k waterstone isn't completely flat. It's not far off, only just detectable when i laid it on a piece of glass, but i'm still obsessive enough to want it perfect!

Question is: what the hell do I use to flatten it? i used wet/dry sandpaper on glass for my norton, but it seems that the chinese 12k would be a lot harder. Or am I wrong?

Has anyone flattened one of these before?

Cheers,
Ian.

Hi Ian:

Many of us have lapped a Chinese 12K. Some of these stones as their owners have described the lapping process, seem to be harder or softer. I have a very hard Chinese 12K that took quite some time on a diamond plate (DMT D8C at the time) to lap. Normally on natural stones like Belgian Combos, Belgian Blue, Barber Hones, etc I lap both sides. I stopped after lapping one surface of my 12K because it took such effort and I must be lazy.

Have at it with your wet/dry sandpaper on glass and use lots of water. Draw your pencil grid and sooner or later, the grid will be gone. Then if you're really determined, draw another grid and lap until the second one is gone. Then, happy razor edge polishing!

Chris L

That makes sense chris, I'll give it a go. To be honest, it's probably so close to flat that it wouldn't matter (I've done 4 or 5 razors on it and they went ok). Still, I'm pretty obsessive, and i don't think my sickness will let me leave it alone!!

ian.

I had to lap mine twice.

Some 1k sand paper, something pretty flat to work on and some elbow grease and... voila ...

The second round of flattening is when I learned just how hard these stones are.


Dont forget to knock off the corners and edges. It does make a difference.

I posted this method a while ago for some insight, and I got mixed replies, but this is how I flatten my 12K:

I draw a grid and rub it off with a Norton Flattening Stone. Then I draw another grid and rub it off with 600 grit sandpaper wrapped around a piece of 12" x 5" x 0.25" glass. Rinse and repeat with a freshly drawn grid and a 1000 grit piece of sandpaper.

My 12K is seems really hard to me, compared to my norton, and I've found that this progressive method really makes my 12K feel slick and with three grids to rub off, by the time your finished you may find that you're having trouble peeling the stone from the glass!

I'm also obsessive about flatness!

Good Luck!

I am always amazed when someone describes lapping their 12K with a Norton lapping stone. Mine was way too hard for that and it just trashed my Norton stone without having any effect on the 12K. I guess that's just part of the mystique of using natural stones, like Forrest Gump's chocolates, you never know what you're going to get!