Thread: scratched my chinese 12k with DMT 600 grit

Good evening.
I lapped my chinese 12k with my DMT diamond plate (which is "fine" and 600 grit I think) and now my hone has scratches on it.
what should I do to get it absolutely smooth again?

Thanks

You can get the scratches out with a softer stone of low grit. Just use your lowest grit waterstone on it and they will come out.

Lapping a Chinese 12k waterstone can be a difficult task.
Because of its slatish nature and its hardness, diamond lapping stones leave nasty scratches on them.
I lapped mine with a DMT extra fine (1.200) and it did no good, although on other waterstones the fine (600) is doing a great, scratch free job.
You can use the C12k as it is, with the scratches, and see if you get any trouble, like scratches on the bevel or microchips.
If you´re not sure and want the best out of the stone you can polish the surface.
I lapped it until flat on sandpaper up to p1.000. Then I rubbed a small piece (credit card size) of a belgian blue against it until the scratches were gone
and the dull surface became a marble mirror. The belgian blue is not that expensive, so no big waste here, and works great because it is quite hard itself.
But it takes hours. Literally. It took me 3-4 hours of rubbing the small belgian against the chinese

Originally Posted by HNSB

You can get the scratches out with a softer stone of low grit. Just use your lowest grit waterstone on it and they will come out.

Thanks, will Norton 4k do?

Lapping a Chinese 12k with any of the above will take a lifetime. They're as hard as diamonds, and cheaper than a beligian blue. I'd recommend starting with at least, a DMT C, if not XX, then, and only once it's flat, move on to some fine grit wet sandpaper. If you don't have a DMT C or XX, use 220 grit to start, really.

You should never use DMT fine for lapping, not my opinion, DMT's, you will trash it. Also, If you want to use wet sandpaper, try wrapping it around a dmt plate. That gives you nice flat surface, and a make shift sanding/lapping block.

Originally Posted by zib

Lapping a Chinese 12k with any of the above will take a lifetime. They're as hard as diamonds, and cheaper than a beligian blue. I'd recommend starting with at least, a DMT C, if not XX, then, and only once it's flat, move on to some fine grit wet sandpaper. If you don't have a DMT C or XX, use 220 grit to start, really.

You should never use DMT fine for lapping, not my opinion, DMT's, you will trash it. Also, If you want to use wet sandpaper, try wrapping it around a dmt plate. That gives you nice flat surface, and a make shift sanding/lapping block.

Thanks,
I have already lapped it flat with DMT fine, but it is scratchy. so what grit sand paper do I need to take out the scratches?

I just got done lapping mine and I started with 400 grit and progressed as follows: 800 grit, 1000 grit, 2000 grit, and 3000 grit. All were 3M wet/dry I found at auto parts store. It wasn't as hard as I expected, but it did take an hour. Of you're just wanting to finish it, I think I'd start with 1k and go from there. I'm new at this, so I'm sure there's more informed people, but this worked for me. This was done wet of course. Btw, it's super smooth and when wet you can easily see your reflection on the surface

The Dmt's are Diamond's, so it will leave scratches. I'd start with the 400 grit wet, as stated above, then progress up, use 600, 800, and 1000 grit. See how it comes out. You may be happy once you finish with the 1000 grit. I used to restore old barber hones. By the time I got to the 1000 grit, they looked shiny and new....As I mentioned, try wrapping the wet sandpaper tightly around your dmt plate, It works pretty good.....

@ zib,

My swaty never came out shiny even after 2k. Should u lap that dry? Sorry to hijack the thread.

Use aluminium oxide polishing powder of floatglass.