PDA

View Full Version : chosera stones



azchef
01-09-2013, 11:43 PM
Good evening
I am.wondering if anyone has had problems with either the 1k or 5k chosera stones? Both of mine have cracked in almost the same spot. They were not dropped or anything. Any. Help or info would be great since they are not cheap.

Mingooch
01-09-2013, 11:47 PM
Have both for a few years with no issues, so sorry I cant help. Mine have been great

ThEoRy
01-10-2013, 12:08 AM
I have heard of chooseras splitting when permasoaked. The bonding agent softens and weakens when soared too long.

zitangy
01-10-2013, 12:44 AM
Been using mine for almost 12 months. ( 1k Greencolor, and 5K grey)

Most of the time, i leave it soaked for abt 8 hours each time as i wld empty the water trough only at the end of the day.

Logically when it things cracks.. its either due to expansion or contraction. As for stones, I believe that it is the latter as it can only absorb water till the saturation point when it dries up it contracts adn hence the crack. Another factor factor could be the humidity level in yr area is too low. IF so.. it needs some juice.

Hope that this helps in determining the crack of your problem.
Have fun adn stay sharp....

rgds

d

Slow drying ( natural air dry) wld be best as if the drying process is too fast ( near heat source) it may crack also..

wsfarrell
01-10-2013, 12:53 AM
I think it says on the stone not to soak it for more than an hour.

Most of them will develop the spider web crazing on the surface no matter how carefully they are dried, but in my experience this is not harmful.

Schtoo
01-10-2013, 02:54 AM
They shouldn't be soaked for more than 1 hour due to the binder used, longer can weaken the magnesia binder and it's not reversible i.e; once it's happened, nothing will fix it.

Drying needs to be gradual, and I would think that as you're in Arizona (Arid-zona?) it's pretty dry there, so drying nice and slowly might be a problem.

Choseras are known to 'move' when wetted, and once wet they will expand and contract when dry. Rapid drying will force the outer surface to dry before the core has dried equally, and the dry outside may contract, causing stress cracks in the surface. It is not predictable when or if this will happen, but it's not unheard of either.

If the stones are still usable, then use them. If not, I'm not sure what you can do other than try and ask where you bought them for advice and support.

Sorry. It's the nature of these beasts.

Stu.

Duckfat
01-10-2013, 08:49 PM
I've had the 1K for at least three years. No problems.

EdipisReks
01-10-2013, 08:54 PM
what kind of crack? cracked in half? small surface cracks? i've had 2 1k Choseras, and both have developed surface cracks (crazing). if that is what you are talking about, it's my understanding that it's normal.

RRLOVER
01-10-2013, 09:14 PM
I had my 5k crack in half.I never soaked them longer then 20 minutes and let them dry in the basement.

mpukas
01-10-2013, 09:32 PM
They shouldn't be soaked for more than 1 hour due to the binder used, longer can weaken the magnesia binder and it's not reversible i.e; once it's happened, nothing will fix it.

Drying needs to be gradual, and I would think that as you're in Arizona (Arid-zona?) it's pretty dry there, so drying nice and slowly might be a problem.

Choseras are known to 'move' when wetted, and once wet they will expand and contract when dry. Rapid drying will force the outer surface to dry before the core has dried equally, and the dry outside may contract, causing stress cracks in the surface. It is not predictable when or if this will happen, but it's not unheard of either.

If the stones are still usable, then use them. If not, I'm not sure what you can do other than try and ask where you bought them for advice and support.

Sorry. It's the nature of these beasts.

Stu.

Stu - just curious - is it possible to mount the Chosera stones on some sort of base, such as a peice of stone or composite counter top material (Corian), to prevent cracking in half? And if so, could a cracked in half stone be mounted on a base, flattened, and then used as normal?

I've read about Chosera stones cracking from other folks. Your post makes a lot of sense as to why this happens - thanks much for the info! mpp

franzb69
01-10-2013, 11:16 PM
if they crack and seem to be still usable i've read that you can always just epoxy them together and use them as normal.

=D

azchef
01-11-2013, 01:46 AM
if they crack and seem to be still usable i've read that you can always just epoxy them together and use them as normal.

=D
Franbz what type of epoxy

franzb69
01-11-2013, 02:05 AM
check this out

http://japaneseknifesharpening.blogspot.com/2012/01/how-to-attaching-sharpening-stone-to.html

dunno what stuff you guys got available in the states since i live halfway across the world, but i think the link i posted might help you get started.

i'd put it on a base like that as well then epoxy the broken bits together to make for a stronger bond. besides, with a base u get to use the whole thing all the way down to the base. makes for a taller stone which makes sharpening easier as well.

Schtoo
01-11-2013, 06:26 AM
Stu - just curious - is it possible to mount the Chosera stones on some sort of base, such as a peice of stone or composite counter top material (Corian), to prevent cracking in half? And if so, could a cracked in half stone be mounted on a base, flattened, and then used as normal?

I've read about Chosera stones cracking from other folks. Your post makes a lot of sense as to why this happens - thanks much for the info! mpp

They come on a base, as standard. The 'odd balls' have no base...

So yeah, I suppose you could easily mount them on a base of whatever you think is right and proper. ;)

(I'd probably be lazy and mount a stone to an Atoma base plate. They're cheap, flat and don't care about water.)

For the record, I treat my Choseras rather poorly and have had no problems. Not that I actually use them all that often...

Stu.

GlassEye
01-11-2013, 02:53 PM
Stu,
I also have Chosera stones with no base, no problems yet. Would I gain any benefit from applying shellac to the sides and bottom, like my natural stones, or should I just find something to mount them to?

Lefty
01-11-2013, 03:23 PM
Seems like a possible issue I wouldn't feel like putting up with. I'll stoic with Suehiro and King, thanks.

Schtoo
01-12-2013, 12:21 AM
Stu,
I also have Chosera stones with no base, no problems yet. Would I gain any benefit from applying shellac to the sides and bottom, like my natural stones, or should I just find something to mount them to?

Maybe, but as I said, it's the nature of these beasts so I wouldn't mess with them too much (aside from a base) and just learn to live with them.

I'm with Lefty though. I'll never be a fan of anything that's troublesome to deal with if there's an alternative that'll get the job done without all the bubble wrap treatment.

(I get enough bubble wrap in my life packing boxes!)

Stu.