Thread: Naniwa 12k feeling rough

You can finish them with higher grit wet/dry sandpaper, 400-1000 grit. I wrap the wet sandpaper around my DMT C and use it in the sink. The DMT gives you that flat surface. The Naniwa's create a good deal of swarf. It's good to lapp them under running water...

There is another possibility to consider. Let me describe what happens with my Naniwa 12K... I lap it, and it has a consistent color. As I use it, the swarf (fine metal particles removed from the edge) builds up on the hone. But, it doesn't always build up in a uniform gray film across the hone. Dark dots of accumulated swarf sometimes appear that get bigger and darker. When this happens, the honing efficiency decreases. It indicates that it is time to lap again.

It sounds like the dark dots appeared before honing. But, perchance you have honed a little, the dots might be a natural accumulation of swarf pattern. And, if you haven't honed (as it sounds to be the case) then ignore this message, and I will defer to the above comments.

Originally Posted by mjsorkin

Can't naniwas be lapped with some sandpaper? Norton stones also feel a little rough after the lapping plate because it's 220 grit. I finish the stones on wet dry paper. The lapping plate is durable but will sometimes deposit a little blue slurry, maybe this caused the discoloration?

You can use sandpaper, but in the long run, you'll spend more money on it than if you had gotten the DMT. Should work fine for a short term solution, but cheap brands can sometimes leave grit embedded. Stick w/ Norton or 3M brands to avoid this.

Originally Posted by Blix

The Answer to the Ultimate Question of Life, the Universe, and Everything= 325

I thought it was 42! Dont panic.

Originally Posted by RobertHardy

When I was done lapping however, I noticed that the top of the Naniwa had become slightly discolored with many small dots and it was no longer as silky smooth as when I received it.

The small dots (or speckles, whatever you want to call them) are normal for the Naniwa after lapping, but it should be smooth to the touch. Mine was actually quite rough right out of the box, but became silky smooth after the initial flattening session. FWIW I use a DMT 8C for lapping.

I only got 3k & 5k Naniwas and there should be a movie about honing, in my world it would be titled: "There Will Be Speckles."

Get a D8C. No AD jokes, because in this case acquiring the product helps to end getting more products.