Hello! Got a stone issue, let me know where to place this request.

[Aidan]

Hi, I recently bought 3 Naniwa Pro stones and have an issue with them. They all, but particularly the 1000 grit seem to exude a thin rubbery glaze which balls under my thumb when I rub it. I only really noticed this after setting them to dry after use. I did not soak them, I used only s splash of water but the knife felt odd when passing it over the stone, like it wasn’t connecting part of the time, I keep clearing away the slurry. It is as if there was a protective glaze on it in the first place. After washing and standing them to dry I noticed this residue on the surface and I am bewildered. I rewashed them in cold water, no soap or solvent but the residue keeps returning. Has anyone come across this before and know any possible solution?. I am sending the 1000 grit back definitely as a small hole appeared on the surface too. But perhaps I am not used to using these stones and I am making a rookie’s error.
Any advice gratefully received
Aidan

 

[bkultra]

Welcome to the forum, I'll move this to the correct section.

 

[soigne_west]

Do you have a lapping plate or flattening stone? I found that some stones just preform better after a good lapping.

 

[Aidan]

I used the Naniwa dressing stone but I have to say the exudate is still coming through some 5 days later.

 

[esoo]

While I'm not an expert by any means, maybe a picture of the issue will help the more knowledgeable?

 

[Aidan]

I have tried to take a photo but this phone can’t get it.

 

[VICTOR J CREAZZI]

This sounds very strange. I use Naniwa Choseras (pro) in the 600, 1k, 3k, and 5k and I dont think I've experienced anything as bad as what you are reporting. The stones do seem to develop a slight glase when sitting unused, but a quick rub with that dressing stone will quickly remove it. Were the stones new when you got them? It almost sounds as if someone used a honing oil or solution on them.

 

[ModRQC]

Was the box in which it came in good condition? That could be a clue.

 

[Aidan]

Bought new fromknives and tools. In box as new, was wrapped in bubble wrap inside the box.

 

[VICTOR J CREAZZI]

What is your general location? Perhaps someone with experience with the same stones could take a look. Short of that see what the seller has to say about them.

 

[da_mich*]

This sounds strange. I have some Naniwa Chosera and SS Stones but never had this problem too. The only Chosera|Professional problem I know is the crack issue. Try a ~P240 Sandpaper at a flat surface. Maybe it will help you.

 

[ModRQC]

@Benuser is an old-time user of these, and knowledgeable. He might chime in.

 

[Benuser]

Not familiar to me either, this problem. With @soigne_west I would suggest serious lapping before use.
Knivesandtools.* are very serious guys.

 

[Aidan]

Knivesandtools.* are very serious guys.....
Well they’re not in a hurry to answer my emails

 

[Nemo]

Never had this issue with my Choseras FWIW

 

[soigne_west]

Knivesandtools.* are very serious guys.....
Well they’re not in a hurry to answer my emails

There’s also a pandemic and worldwide protest going on so a little patience is your friend.

 

[PotterMcMuck]

I have Naniwas from 400 up to 12,000 grit, some are Choseras/Professional stones and some are SuperStones. They all need to be lapped before use, as they come with some sort of protective layer on them. I don't know what the layer is made of, but they don't really work properly until that layer is gone. Don't forget to chamfer the edges while you're at it. No need to buy an expensive lapping plate, you can lap them with wet/dry sandpaper (some people say 600 grit, but I like 400 grit, personally) placed on any flat surface - glass, granite, your countertop, etc. Just be sure the surface is perfectly flat, otherwise your stones won't be flat either.

 

[ModRQC]

Without lapping plate I used 150 for my coarse, 220 for my med, then used the med for the fine stone which mainly needed cleaning anyhow. Not a recipe of wonders. Just that sandpaper works well.

However my atoma 140 under running water takes much faster care of any of them. It also depends on what surface you want. Coarser grit lapping vs finer grit lapping is not the same surface to start with. Muddy stones perhaps will hide the difference faster, but Shapton pros are slow to mud and the coarser/finer surface one imparts holds that much longer.

 

[Aidan]

There’s also a pandemic and worldwide protest going on so a little patience is your friend.

Hmmm... not so slow in taking the money, and to be fair delivery was in good time.

 

[Aidan]

I have Naniwas from 400 up to 12,000 grit, some are Choseras/Professional stones and some are SuperStones. They all need to be lapped before use, as they come with some sort of protective layer on them. I don't know what the layer is made of, but they don't really work properly until that layer is gone. Don't forget to chamfer the edges while you're at it.

This is interesting, nobody has mentioned this before nor has any online vendor, and no instructions/ supporting information comes with the stones. But it would go some way to explaining the phenomenon

 

[kayman67]

I did. Also for Kramer stones and why some reviews understood nothing.

 

[M1k3]

It happens with Shapton stones. The top layer sucks. It works but sucks. Almost waxy. Give it a good lapping.

 

[DHunter86]

I never had that issue with my Chosera stones. But a seller in Japan did tell me there was a film on some of the specially made Naniwa ceramic stones they carried. So it wouldn't come as a surprised if their regular lines came with a film.

 

[Aidan]

I don’t fully understand though. The residue continues to exude from the stone 5 or 6 days after use, I did use the dressing stone and have thoroughly cleaned and dried it since. My view is either it’s picked something up from the dressing stone or there’s a manufacturing fault

 

[DHunter86]

I'm not sure how much material you've expanded from the stone through use and the dressing stones. From what I've heard the pro stones wear slightly slower than the Choseras, and those wear really slowly from use in my experience. I'd reckon if it indeed was a film, you'd need to use up the first half millimeter or so to get through the film.

I'd contact the seller nonetheless just to be sure.

 

[Aidan]

I managed to get a photo in daylight. This is the material after I have rubbed it with my thumb

 

[DHunter86]

I've never had that issue and hence can't be sure what it is. Though it being from a film is quite likely.

FWIW, I've only ever had such residue from lacquer seeping onto my sharpening surface when sealing natural sharpening stones.

Similar to what the others have said, I'd try lapping off the top surface with a diamond plate or sandpaper. That flattens out the surface and might solve your problem too.

Seeing that it affects all your stones and I'm assuming they're different grits, I'd say that it's either due to something seeping in during transport and storage, or a film put on during the manufacturing process.

Otherwise, if you'd prefer not to deal with the issue, just wait till the seller replies and maybe get them replaced.

 

[Knife2meatu]

I must say, I'd guess that's coming either from your thumb, or something being rubbed on the stone. Maybe in drying, or in 'cleaning'.

 

[Aidan]

Certainly not from my skin, certainly coming from the stone. After I rub it away and return later to look at it again, another fine layer has appeared particularly towards the edge of the stone away from the main sharpening area. I have only washed it in clean tepid running water.

 

[mpier]

I managed to get a photo in daylight. This is the material after I have rubbed it with my thumb