Let's talk about drying of Japanese water stones

We all know the debate about how long a soaking stone needs before one can use it (and this of course depends on the stone itself) and often people prefer splash&go stones just to be able to use them whenever the need comes without planning to soak then 10 - 30 minutes before actual use.

Strangely - nobody ever talks or cares about how long it takes to DRY a stone. I wanted to test that several times already, but my last sharpening session gave me the best opportunity, because all 3 stone (Gesshin 400, 2000 and 6000) were soaked for 2 days (yes, days - I had hard time to find the time to get to sharpening, so the stones kept waiting in water). But this was a great starting point since one could assume that the stones are completely saturated with water.

Just to remind you - the 400 and 2000 are soakers, the 6000 is splash&go.

So - once the sharpening was finished I have decided to wight the stones every couple of hours to see
a)how much water they actually absorbed
b) how long it will take to dry them completely.

I have used our digital kitchen scales with measurement precision of 1g to get the job done. Drying took place on the kitchen counter (the stones were put across plastic stone holder base - so there was minimal contact and very most of the stone surface was exposed to air), no direct sunlight, normal temperature and humidity.

The results:

a) Absorption ability:
Gesshin 400:
- soaked: 1006g
- dried: 848g
- relative: 18.5%

Gesshin 2000:
- soaked: 984g
- dried: 805g
- relative: 22.2%

Gesshin 6000:
- soaked: 821g
- dried: 808g
- relative: 1.6%

b) Drying time:
- Gesshin 400: 5 days
- Gesshin 2000: 5 days
- Gesshin 6000: 15 - 20 hours

I still want to make graphs of the drying process (I have 25 measurements for each stone) - I am just lazy

So - the advantage of splash&go stones is not only that they are ready within few minutes, but they also dry much faster.

One caveat though - I did not have comparable grit stones in the "test" - I would not be surprised if 1000 grit splash& go stone would need a little longer to dry than 6000 splash&go, but that is just a speculation.

Nice work! I hadn't thought of weighing them. Mine tend to take at least 7 days to fully dry. I end up leaving them out for about 2 weeks most of the time.

I've been wondering something lately and I'll propose it here (if you don't mind)-
Let's say I soak my stones and for the most part just leave them in water, changing the water every so often. Kind of a pain currently but ooh well. This got me to thinking about cryovaccing the stones individually while in there soaked state. The quick thinking on this is the lack of air/oxygen will prevent drying and mildew build. But now the stones are under a little pressure (I would be using a chamber vac with adjustable settings), could this be a bad thing? I'd love to hear what you think about this.

I'm hoping this fits in with the OT topic, not trying to steal the thread or steer it into a different direction...

I think cryovacing would be an invitation to mold. I left a stone wet in a closed toolbox for a couple days and it grew mold. I managed to get rid of it in the dishwasher (not recommending that, but it worked for me). I'm not sure mold spores need air. Just speculation though.

Mold or not you definitely invite anaerobic bacteria to grow in a high moisture environment with no competitive bacteria. We have a HACCP certified sous vide program and we aren't even allowed to hold fresh fish in cryovac unless we freeze (read: destroy) it first. Definitely a risk.

As far as soaking It depends completely on the stone. I learned with my first set of Shapton Professionals that if you don't use (read: wet) them regularly they actually crack because they dry out. The Shapton rep told me that they were made for the domestic Japanese market and that the bonding agent used is only suitable in high humidity environments. I was living in very dry Texas when it cracked and I live in very humid DC now and have had no new problems. All stones have different needs. Some stones will even dissolve if you hold them in water too long.

That is indeed correct - one should know how the take care of given stones. For example - there are stones that are NOT to be soaked at all - Chosera stones come to my mind. There were several reports of Chosera stones cracking what was mostly related to too long soaking.

Cool Matus have a few gesshin stones never thought about drying time,I just leave them open air kitchen to dry,usually use them again before complete dry.

Chef I was wondering how your shapton pro cracked.In Hawaii also no problem with 2K pro.It is really easy to use run some water on it set to go.After reading your experience make sure let it dry in the shade.

What happened was that after not using it for about months I pulled it out and a spider web pattern of fissures had developed. That being said I bought replacements and haven't had any problem. Dollar for dollar the best stones on the market in my opinion. Just be sure to use them a lot if you live in a dry place.

ChefCosta, I have not yet heard of Gesshin stones developing fissures - are you sure they were not dried too quickly? I would give Jon a call if that were to happen to me. But I agree - these stones are awesome.

Matus,
I was talking about Shapton Professional Stones.

ChefCosta said:

Matus,
I was talking about Shapton Professional Stones.

Click to expand...

I see, I apologize for the confusion.