Thread: Sealing synthetic waterstones

Originally Posted by holli4pirating

[...] that penetrates into the bottom [...]

heh heh heh.

Originally Posted by Utopian

[...] If water only can enter on the top it will soak into the hone more there than in other areas. Some hones do swell slightly. Having only one point of entry and egress for the water might cause internal stress. [...]

This is a something I've wondered about, yes. That said, I'm already using Choseras which come attached to bases; so by necessity there's always some parts which get wetter than others (heh).

When using them, I just spray the top with a little water, let that soak in for a minute or two to improve the feeling of the hone and then add a little more water as needed. In fact, doing it this way, I notice that the edges of the hone need more water sooner than the middle. These Naniwas aren't very thirsty at all, so I assume that water doesn't soak in very deep, but it does seem to get drawn into the edges more readily.

Which is to say that: (a) I'm already wetting various sections of the stone differently -- particularly if one also considers the deeper parts of the stone which I guess never get any water, assuming no prolonged soaking -- so that differential expansion/contraction is presumably already happening now, and that won't change much if I seal the underside and the sides, I don't think; and (b) given that the edges of the top already dry out a little faster than the middle, I actually imagine that sealing the sides could make the entire top face act more uniformly with regards to water absorption.

But these are just some of my observations based on limited usage, what I hypothesize could explain them, and what I imagine might happen if I apply some sealant to the hones. I'll be sure to post back with results if I go ahead with the more expensive magnesia waterstones.

As far the King stone is concerned, it won't be subjected to repeated wet/dry cycles if all goes to plan, given that it usually just resides in water all the time. I imagine that if I seal it on 5 sides when it's dry, then water will just soak in from the open side, puddle inside it when in use, and just kind of stay there when it goes back in the bucket -- Assuming the urethane holds up to underwater use, which isn't obvious to me at this point.

However, this talk of expansion and contraction of hones in relation to their water content has got me wondering, and I think that I will take a couple of measurements of Kings in both their dry and soaked states, just for fun. It would be more interesting to perform a similar test on a magnesia Naniwa, but I don't want to soak one for any prolonged period of time.

In the meantime, I have a needlessly glossy dressing stone in need of further curing before I try dunking it in water...

I've only ever sealed one synth, though Max at JNS recommends sealing all stones natural or synth. The Shapton Pros appear to be sealed on the sides (and on the back for the old ones and Kuromaku) with something like tile sealer or what the Japanese called 'Hone Coat'.

Once I tried sealing a large Suehiro 1k - basically a King 1k - with lacquer to do what you mentioned, reduce water absorption. It failed miserably. However, it dried out in about the same time, many days lol, so I don't think there's any risk of water staying in a hone that you'd perma-soak anyway.

I definitely wouldn't seal a stone that I perma-soaked, I'd doubt that the coating would stay on over time and I don't understand what you'd accomplish by coating a perma-soaked stone.

Cheers, Steve

Hey, Steve56! It is actually some of your posts about sealing a Snow White, and it then doing well -- whereas one of your acquaintances went through several (4, I think?) hones which all had cracking problems -- which got me on this kick.

Originally Posted by Steve56

[...] Once I tried sealing a large Suehiro 1k - basically a King 1k - with lacquer to do what you mentioned, reduce water absorption. It failed miserably. [...]

Could you expound on what about it failed miserably? I am rather curious, for obvious reasons.

Originally Posted by Steve56

[...] I definitely wouldn't seal a stone that I perma-soaked, I'd doubt that the coating would stay on over time and I don't understand what you'd accomplish by coating a perma-soaked stone. [...]

Yes, the durability of the coating when immersed in water is an open question. Really though, I am using the soakers as more of a test to see how well the urethane will hold up before slathering it onto the Snow White which should be a much easier proposition for the sealant to handle, long term.
But, I am also curious to see if maybe I can turn the King into a kind of "perma-wet" stone; that seems like it would be interesting also -- in the somewhat unlikely scenario that the urethane coating proves both watertight and resistant to perpetual contact with water... And as for the 220 pink brick -- that thing is, in my admittedly limited experience with waterstones, the first time I am getting frustrated with how thirsty a stone is; no soaking for any length of time gets it to hold any significant amount of water on top; I can work up a mud which then holds a little water, but doing so wears the stone faster than I need to, and also limits me to grinding on said mud, which is slower than light pressure on the stone with no mud, and therefore not necessarily how I would prefer to use the stone in all cases. Hence, I'd get more use out of Pinky if I could finagle some way for it to hold more water near its surface and not just pass it straight through like nickel beer.

Hey Occamstrop!

The Suehiro coat failed because it absorbed just as much water as before and took just as long to dry.

The Snow White failed too, just not with me. It never cracked on me with or without the coating, but after coating and using it for a while, I sent it to a friend in Lake City, FL who had been through 4. Sure enough, after a while he notices fine spiderweb cracks on the surface which is how all 4 of his began failing.

I don't know what the difference/cause is. My first thought was water, but we both use distilled water to hone with. Humidity maybe?

The idea to coat the Snow White came from the Shapton Kuromaku/Pros that also once had a cracking problem in the Westen US. Allegedly they reformulated the stones, but the Pros also appear to be coated on the sides (they're 2-sided now) and the Kuromakus on the sides and graphics side. So I decided to try coating the sides and back of the SW then send it to my pal as an 'acid test'. Oh well, sometimes you eat the bear and sometimes the bear eats you...

Cheers, Steve

I've sealed my 1k & 3k Choseras and my 5k Chosera, that I purchased used, came to me sealed. I live in dry Colorado. I don't think the sealing had any effect on the checking. My 3k was checked when I got it and seems to have healed itself. The 5k checked after I got it, but I think that is just the nature of the stone.

Keep in mind that sealing can lead to mould if the water cannot evaporate.

5 years and a full set of Naniwas and no sealing , with not a problem a one,, I do like Glen, soak for a few while using the preceding stone, set down for a few minutes so any thing that needs to normalizes, then my DMT for 3-4 figure 8,s to some slurry going then get after it. like I said no problems, and my 5k and the 8k snow white shoed those spider webs or crazing, yet has had no effect on its ability to hone smoothly. Tc