Thread: Scratch marks in stones after lapping

Sometimes a high diamond will resist the above methods of breaking in a new DMT.

If you are still getting scratches carefully do one lap at a time to locate the high diamond. Then go after that spot with a screwdriver. You may have to test in two directions at 90 degrees to precisely locate it.

Or sharpen a couple kitchen knives on them, you will feel where the high spots are.

Also, start by beveling the edges of the stone, that will knock down the high spots.

I just had same issue two days ago with my new dmt and shaptons. I even honed a couple knives before using it to lap my hones. It still left scratches in my hones which didn't affect honing at all. You're gonna be fine, no worries

Yup. I call those scratches negative honing surfaces. They don't hurt anything and over time your diamond plate will sort itself out.

Agreed. It's only cosmetic. No sense in scraping more of the hone material off. Definitely season the DMT before using it again.

I remember when I bought my dmt with Shapton glass stones.

A high patch destroyed my honing surface, I couldn't figure out why my 30 k felt so rough when honing.
Years later and much effort my dmt is worn and even.

As long as it is not one area with a high patch you will be ok.
The scratches shouldn't effect the honing.

Try the screw driver shank method ..

Even a decently worn 1200 plate will leave some scratches, it is 1200 after all, though as Ron says the scratches are not harmful. Those scratches though, always seemed to be 'not in harmony' with the idea of a high end jnat so now I lap using sandpaper on plate glass up to 2000 grit on the finest finishers. Here's a couple of tips to try.

If you're using synths, try the King 8000 grit slurry stone to clean hones after use and smooth the surface after lapping. This stone I believe, was designed to create slurry, and it does, but I can tell the surface is much smoother than after using the Naniwa brown biscuit.

On a jnat finisher, nearly all the wear comes from raising the slurry with a tomo, not honing the razor. Use the tomo with even pressure over the entire hone surface and you'll almost never have to lap the stone.

Cheers, Steve

Originally Posted by Steve56

Even a decently worn 1200 plate will leave some scratches, it is 1200 after all, though as Ron says the scratches are not harmful. Those scratches though, always seemed to be 'not in harmony' with the idea of a high end jnat so now I lap using sandpaper on plate glass up to 2000 grit on the finest finishers. Here's a couple of tips to try.

If you're using synths, try the King 8000 grit slurry stone to clean hones after use and smooth the surface after lapping. This stone I believe, was designed to create slurry, and it does, but I can tell the surface is much smoother than after using the Naniwa brown biscuit.

On a jnat finisher, nearly all the wear comes from raising the slurry with a tomo, not honing the razor. Use the tomo with even pressure over the entire hone surface and you'll almost never have to lap the stone.

Cheers, Steve

Replace Jnat and insert any finishing stone, synthetics included, and I'm of the same mindset. The scratches may not be detrimental, but they still kick up my OCD. I still use the DMT or a diamond plate when I need to flatten, but after the stone is flat like I want it's time to switch to sand paper and get the scratches out. Well, depending on the stone.

My low grit 800 and 1K stones only get hit with the DMT. Middle grit and higher get 1-2K at least. My naturals are all high polished.

The naniwa biscuit is pretty coarse, but I'm coming to like it. Seems to clean things up nicely and doesn't leave scratches that are too terribly deep. It makes sense the King slurry stone would be finer though. I think I read somewhere the Naniwa biscuit is something like 400 grit? The surface I've been using doesn't feel that coarse, but it sure does clean my synthetics off quick. I might have to put one of those King stones on the wishlist somewhere, I like the sound of it.

Another option is to use a small piece of cheap hard Arkansas hone for creating slurry. They are common for knives and often only cost a few bucks. Their advantage is that they are so hard that all of the slurry will come from the synthetic and itwill leave no scratches at all.

Originally Posted by Steve56

Even a decently worn 1200 plate will leave some scratches, it is 1200 after all, though as Ron says the scratches are not harmful. Those scratches though, always seemed to be 'not in harmony' with the idea of a high end jnat so now I lap using sandpaper on plate glass up to 2000 grit on the finest finishers. Here's a couple of tips to try.

If you're using synths, try the King 8000 grit slurry stone to clean hones after use and smooth the surface after lapping. This stone I believe, was designed to create slurry, and it does, but I can tell the surface is much smoother than after using the Naniwa brown biscuit.

On a jnat finisher, nearly all the wear comes from raising the slurry with a tomo, not honing the razor. Use the tomo with even pressure over the entire hone surface and you'll almost never have to lap the stone.

Cheers, Steve

I never thought of using high grit sandpaper on my jnats.
Normally I use my Shapton lapping plate and then I do some 1200 Atoma, finally I break a sweat using a soft nagura.
What I find shocking is how easily it is to dish out (probably a fine shallow dish)my Nakayama which is hard and I do slurry from the edges.
In saying that though, I do a lot of honing on that stone.
I will try the sandpaper method next time, hopefully no bits will lodge in the stone.
Cheers..