What's up with this?

My 1200/1600 ceramic stone has a weird pattern of lines that I thought were going to disappear but haven’t. My second stone of the pair doesn’t have this pattern…

Try cleaning them with Windex and a toothbrush. Hopefully that helps.

Thanks but I have cleaned them thoroughly and after a few passes they look like this.

My .6micron white ceramic stones look grey after one knife sharpening. I use my sonic care toothbrush with an old brush head and Windex to clean them up. Takes about a minute each stone and they look brand new again.

It’s not that they get dirty it looks like I’m only making contact on those lines

Can you lap them together to wear down the high spots?

I think it looks okay and should break in fairly quickly. You can rub them against a diamond stone to flatten them if you need. It helps to keep the stones wet when you do that. If it doesn’t resolve easily, don’t worry because they’re under warranty and we’ll definitely replace them if need be.

I’ve sharpened about 15 knives already I’ll try lapping them. Should I use a specific stone I was going to use the 200s.

I would mark gridlines on the stone with a pencil and use a medium grit diamond stone to lap them with. Once pencil marks are gone you should be fine.

I think that most ceramic stones like this have some degree of surface irregularities. I don’t think it has much on an effect in the finish produced.

I lapped my ceramic stones and it changed their apparent grit. Apparent? Ceramic stones don’t have a “grit” per se. WE assigns a grit which “apparently” are equivalent to the scratch patterns produced by stones of a known grit.

I lapped my 1.4 micron ceramics on a 1200 grit sandpaper and thereafter the stone produced scratches equivalent to 1200 grit. Here’s a photo. The upper left is an area not yet touched by the lapping; the lower right is the lapped area. Further evidence that the surfaces of ceramic stones are not dead flat.

microfine lapped compressed

I’m pretty sure you can restore the original grit by re-lapping the stone on diamond film of the desired grit, but it would take a long time.

Thanks for the suggestion, I ended up using the 200s (face palm) but either way I’m pretty sure they were putting deeper scratches on the edge when I was using them.

…another thing about my ceramics is that they’re chipped along the edges. The 1.4u/.6u ceramics are beveled, I think it would be good to have the 1200/1600s beveled also.