Thread: Flattening Chinese 12k

I purchased mine very recently from Woodcraft and it lapped quickly on the coarse dmt plate. I was suspicious so I drew the lines again, but they disappeared in a couple of minutes. I was just lucky, I guess.

very lucky you are, i remember lapping mine it took quite a while and a lot of wet paper as well but once they are flat i think they stay that way for some time

400 grit wet and dry then 800 grit wet and dry on a piece of plate glass and keep going until the colour is an even grey. Pencil it up if you like but I found the colour change was a perfectly good indicator. Just be prepared to perspire a bit!

Here's a question: since typically harder stones have a finer girt rating (naniwa 10k not included), could it be that those who have these chinese 12k's that are pains to sharpen actually have a finer stone than those who have the softer ones?

I got one today and lapped it on various grits sandpaper on a granite reference slab that is dead flat, and it went pretty quickly for me. The finish is still great, but I can't help but wonder if the finish on the harder 12k's are better....

The blurb on woodcraft.com says the following:

Natural Polishing Water Stone

A dense, hard stone that's perfect for final polishing on all your carving tools, plane blades, chisels or any tool requiring a keen edge.

Extremely fine (12,000+) grit natural water stone quarried in the Guangxi province of China.

Because these natural polishing stones are cut by hand, dimensions may vary slightly.

Maybe the softer ones are 12000 or so, and the harder ones go even higher. This would explain why some use a coticule before the 12k, and some use one after the 12k. I'm sure that the grading of the coticule isn't that specific either, so that's also a factor....

Just a thought.


Ben

Originally Posted by randydance062449

The DMT XXC (125 grit) would probably be the best to do a majority of the work or you can start with a coarse piece of wet/dry sandpaper.

I just got the DMT D8XX two days ago. If you're looking for a lapping plate that's equivalent to an industrial angle grinder without the noise, get this stone. Sakes alive does that lap aggressively! I've got one of the extremely hard 12k stones; you know, the kind that removed the diamonds from Bruce's D8C as if they were arm hairs yielding to a shave ready edge? It took me approx 45 min to lap one side of the 12K when I got it last year.

Enter D8XX..................I lapped the unlapped bottom side of the 12K as an experiment and was literally done with only the weight of the stone in less than 5 minutes. Keep in mind, as Randy said, the pattern it leaves is too coarse as is, and must be finish lapped on a finer lapping plate. Barber hones also wet themselves when they see this D8XX coming.

Originally Posted by Ben325e

Here's a question: since typically harder stones have a finer girt rating (naniwa 10k not included), could it be that those who have these chinese 12k's that are pains to sharpen actually have a finer stone than those who have the softer ones?

I got one today and lapped it on various grits sandpaper on a granite reference slab that is dead flat, and it went pretty quickly for me. The finish is still great, but I can't help but wonder if the finish on the harder 12k's are better....

The blurb on woodcraft.com says the following:

Natural Polishing Water Stone

A dense, hard stone that's perfect for final polishing on all your carving tools, plane blades, chisels or any tool requiring a keen edge.

Extremely fine (12,000+) grit natural water stone quarried in the Guangxi province of China.

Because these natural polishing stones are cut by hand, dimensions may vary slightly.

Maybe the softer ones are 12000 or so, and the harder ones go even higher. This would explain why some use a coticule before the 12k, and some use one after the 12k. I'm sure that the grading of the coticule isn't that specific either, so that's also a factor....

Just a thought.


Ben

Interesting question. If someone had a confirmed "hard" 12k and also had a "soft" 12k, experimentation could be done.

Chris L

I completely agree with you on the D8XX. It makes the lapping of hard hones like the 12K and barber hones almost a joy!

i had thought about the 120 grit to do my fine and medium spydercos but thught they might tear the diamonds out of it, but that is the hone of choice for naturals, even if you need to progress through 320, 600, 1200 that would be the easiest way to do it, i see what others meant when they said they put in 70 hours to lap a set of spydes, i have a lot of hours into mine maybe 20 and im halfway done thankfully i bought my ultrafine lapped here

Originally Posted by Ben325e

Here's a question: since typically harder stones have a finer girt rating (naniwa 10k not included), could it be that those who have these chinese 12k's that are pains to sharpen actually have a finer stone than those who have the softer ones?

I got one today and lapped it on various grits sandpaper on a granite reference slab that is dead flat, and it went pretty quickly for me. The finish is still great, but I can't help but wonder if the finish on the harder 12k's are better....

The blurb on woodcraft.com says the following:

Natural Polishing Water Stone

A dense, hard stone that's perfect for final polishing on all your carving tools, plane blades, chisels or any tool requiring a keen edge.

Extremely fine (12,000+) grit natural water stone quarried in the Guangxi province of China.

Because these natural polishing stones are cut by hand, dimensions may vary slightly.

Maybe the softer ones are 12000 or so, and the harder ones go even higher. This would explain why some use a coticule before the 12k, and some use one after the 12k. I'm sure that the grading of the coticule isn't that specific either, so that's also a factor....

Just a thought.


Ben

You just got yours recently, as did I. Maybe the recently mined ones are softer. Or, as it sounds like you got yours at Woodcraft too, maybe they got a soft batch.

Originally Posted by Swink

You just got yours recently, as did I. Maybe the recently mined ones are softer. Or, as it sounds like you got yours at Woodcraft too, maybe they got a soft batch.

I guess I need to clarify how I lapped mine - like you already read I lapped it on a granite reference plate with sandpaper, various grits. I pressed pretty dang hard on it too. I'd do about 20 or so strokes then I would rotate the stone 180 degrees and do it again, to help ensure that everything stayed even. There is a corner on my stone that isn't flat. I'd say that 90 percent of my stone is flat. I just didn't take it down to that level because 1) it's a long stone, and there is plenty of room for me to hone with; 2) I want my stone to last the rest of my life, so I just left the large flat area, and I'm sure it will get to be 100 percent flat during my lifetime, eventually.

So for all you guys who are flattening the entire stone, then hats off to you, but I'm more than satisfied with the current condition of my stone. I do think that if I were to try to flatten the entire face of the stone, that it would take a decent amount of time.

Ben

Trust me the stone will last the rest of your life without any risk at all. With normal individual usage, your grandson might use it enough to get it to all the way flat. I don't think anyone has to worry about wearing out a natural hone, and certainly not this one!