Naniwa swelling

[JackJ]

I recently purchased the Naniwa 8k and 12k super stones. I dutifully crosshatched them with a pencil and lapped them under running water on a DMT 325. Both were high in the middle and low at the short edges. After my first session with them I let them dry for a couple of days and then checked their flatness again on the same DMT. This time, dry, both stones were high at all four corners--close to opposite what I saw when they were wet.

Has anyone else run into this--Naniwa SS's swelling in the middle when wet? Of course they will always be wet when honing, but complete soaking isn't typically recommended with these, except when lapping, leaving me unsure just how flat they'll be in normal use.

 

[wdwrx]

I've read about it. I've got a 12 K I had out the other night, and I didn't notice it. I don't use the pencil grid much, I just lap lightly everytime after I've had the surface wet for 10 or so minutes ( I start with a slurry anyways ). Mostly I just go with it. I've never noticed that it affects anything.

Easy enough to do a quick check, i guess. I'll give it a go.BRB

 

[wdwrx]

On my particular Nani 12 K, I started with a pencil grid and a couple quick passes on my lapping plate, w/ 220 WD sandpaper, dry. The corners were a little high, and the wear wasn't completely even, but it didn't look like other than what I was kinda expecting. After letting it sit, wet for about 10 minutes, a few passes on the sandpaper didn't show any different the from the pre wet stage, corners were still a little high. I'll check again in a bit, after it's had longer to soak, now that it's been lapped flat.

 

[JackJ]

Sounds like yours is behaving differently from mine, as I would have though 10 minutes enough to bring out the center swell I've seen, but I haven't been rigorous in my testing. I may need to take another look myself.

 

[wdwrx]

hahah your post reminded me that my Nani was sitting there waiting.

It's been damp now for I guess a couple hours, and it is definateley changing. I'd lapped it flat last post, and now it's showing different high spots. So, ya, it obviously is swelling.
hhhmmmm...
I'd swear I never noticed before. Not sure I'm any better off now. i have no idea what to do about it.

 

[SliceOfLife]

Pretty sure the box says not to soak it for this exact reason? Doesn't it?

 

[altshaver]

Should Naniwas be lapped dry? Or should you just use a light coat of water as if you were honing? I have always read that these stones in particular should not be soaked. My guess is that running them under the facet in the sink is soaking them too much.

 

[wdwrx]

Not sure. I don't have the insert any more. I wasn't soaking it though. I just wet the top and let it sit like I would if I was actually using it. While it was sitting, it was just sitting there, no water added, just what was already there.

 

[wdwrx]

... My guess is that running them under the facet in the sink is soaking them too much.

Wow. Really? I've always used plenty of water when using mine. And i do hold it under running water to eliminate any auto-slurry from staying on the hone.

It is a water stone.... how can it not get wet?

 

[mainaman]

Wow. Really? I've always used plenty of water when using mine. And i do hold it under running water to eliminate any auto-slurry from staying on the hone.

It is a water stone.... how can it not get wet?

no they do not absorb water not for that short time anyway.
They are resin bound and tend to bend like that. I recently mounted my 10k on a worn off DMT and so far it looks like the problem is solved.

 

[altshaver]

Wow. Really? I've always used plenty of water when using mine. And i do hold it under running water to eliminate any auto-slurry from staying on the hone.

It is a water stone.... how can it not get wet?

It was just a guess. I never said they shouldn't be wet.

 

[wdwrx]

Just one more reason i seem to prefer my naturals. Way less confusing

 

[altshaver]

wdwrx, I have read your posts on Coticule.be. Do you use Naniwa's in your honing regimen with coticules? I just purchased a coticule and was wondering if using a Naniwa 1K would help with the learning curve on coticules. For instance I would set the bevel using the 1k and then use the coticule for the final steps. Thanks in advance.

 

[wdwrx]

wdwrx, I have read your posts on Coticule.be. Do you use Naniwa's in your honing regimen with coticules? I just purchased a coticule and was wondering if using a Naniwa 1K would help with the learning curve on coticules. For instance I would set the bevel using the 1k and then use the coticule for the final steps. Thanks in advance.

I can't really see how a 1K will speed up the process of learning to use a coti. It's more of a bevel setter, serves a different purpose than what a coti is generally used for.
Poorly said, but what I mean is that the work you do with the 1k is just the beginning. You still need to get that shave worthy finish. After the bevel is set, it becomes all about diluting at the right rate. It has little to do with bevel setting, and all about balancing the slurry dulling effect against the polishing effect.
When I was struggling with my vintage coti, I would use my Nani 12k to get the keenness I couldn't get with that stone (still can't BTW) and then go back to the coti for the edge it would give, but now that I seem to have a fair grasp of my La Dressante ea Blue, I seldom use anything else any more. It becomes redundant.

 

[LarryAndro]

I don't think the wet vs dry, how long to soak before lapping, and other issues are significant issues for several reasons. Lapping is important, but how flat is required flatness?

Most razors I hone are vintage razors that are not completely flat. Almost all have some degree of smile. (Frowns, of course, must be removed.) Even the slightest smile, barely visible, I believe makes the quest for the perfectly flat hone a moot point. With almost every razor I hone, some degree of rotation or twisting or movement is required to ensure that the blade is properly honed. This means that the flatness of the blade is not the primary factor of importance, and how you hone becomes as important and maybe more important.

And, even if a blade is absolutely flat, it is my belief that simple lapping with a DMT in the wet or dry or soaked or whatever state is perfectly fine.

It is natural to want everything perfect. But, in this case, is "perfect" flatness necessary?

(Don't misunderstand! Flatness is very important. I lap my Naniwas with my DMTs as often as anyone else.)

 

[JackJ]

Thanks, Larry, for bringing some important perspective to this issue. I suspect you're right that I'm fretting about a problem that lacks significance given all the variables at play. I'm going to try not to let it bug me much.

 

[matt321]

I noticed the shrink/swell behavior on my 10K a while back. It has been annoying. It is aggravating to find it has a big bulge in the middle requiring a long lapping session and you know good and well it's gonna be dished the next time you pick it up! And then vice versa the next time!

Here is an old (and poor) photo of the "Naniwa Bulge".

I would generally agree with the statements above about over kill, but a poorly flattened hone makes it hard for me to watch the water while honing and learn anything from it.

Also, one can visualize in theory where an edge gets infinitesimally convexed on a dished 8K and then goes to a bulging 10K where the extreme edge never touches the finisher.

 

[PhatMan]

JackJ,

The extent of the shrinkage does get less with time - at least it did for my Naniwas - they seem to have settled down after a year of use !

Have fun !

Best regards

Russ

 

[JackJ]

JackJ,

The extent of the shrinkage does get less with time - at least it did for my Naniwas - they seem to have settled down after a year of use !

Russ

That's good to know! Maybe I'll take them for a swim a couple times a week, whether I'm honing or not.

Jack