Cracked waterstone

[Jim Bress]

Here is a picture of my 10K grit Sigma ceramic waterstone that I bought in 2012.  In the last couple of months cracks have started to develop.  I doubt I have much more time before it just falls apart.  There have been times when I have left it submerged for extended periods and other times when it sat out and dried.  Same for my other stones but they have know problems.  Two questions.

 

1.  Am I doing something to cause these cracks?

 

2. Are waterstones reparable?

 

Thanks,

Jim

[duane88]

When mine crack, I usually create special shaped mini-stones from the bits for gouges.

 

They are not, to my knowledge, repairable. They will crack if they get too cold, as in freezing.

 

When they are dry, it doesn't take too much banging about to start a crack, so you may have just clilnked it against another ston or a bench, or i have even had something like this happen from a slip with a blade that gouges a corner.

[MarkBouquet]

I broke a corner off of a waterstone once, years ago, and glued it back on with polyurethane glue, e.g., Gorilla Glue. It's still holding together years later. I don't know if it's relevant, or even if it's the correct procedure, but I always dry my stones when I'm not actually using them.

[Roger Hargrave]

That yellow stone looks a lot like a fine Japanese stone. If so they are usually excellent. I have used Japanese stones for at least 20 years for all my sharpening requirements. The fine ones are quite soft and especially fragile when they are thin. If knocked they do break quite easily. If the break is clean, allow the stone to dry out completely and simply glue it with a two component glue. (I have never used Gorilla glue, but I am sure Mark is right.) If the stone is cracking in several places, I would consider sending it back to the manufacturer. I am a big fan of sending stuff back. Not to get a replacement or money back, but to help them put to things right if possible. If I had a problem of this nature I would want to know about it.

However, if the stone was (is) thin, consider using the bits as Duane suggests and get yourself a new one. There is nothing quite like unwrapping and using a new stone for the first time.

[Bruce Carlson]

Here is a picture of my 10K grit Sigma ceramic waterstone that I bought in 2012.  In the last couple of months cracks have started to develop.  I doubt I have much more time before it just falls apart.  There have been times when I have left it submerged for extended periods and other times when it sat out and dried.  Same for my other stones but they have know problems.  Two questions.

 

1.  Am I doing something to cause these cracks?

 

2. Are waterstones reparable?

 

Thanks,

Jim

Hi Jim,

 

It looks to me like the support for the stone, which appears to involve a clamping system, is putting undue stress on the stone. Mine are glued down with epoxy to a piece of marine plywood that has been varnished several times over with a water resistant boat varnish. The stones can be leveled against each other and can be worn down until they are paper thin.

 

If the clamping system is putting an uneven stress on these delicate stones you're guaranteed to get cracks.

 

There are a lot of cracks to re-glue but if you can get everything back together it would be good to glue it down to a non-deforming surface where it is held without building in any stress.

 

Bruce

[Roger Hargrave]

Bruce is probably right about the clamp. Although this is the 'official' clamp for Japanese stones. they can be done-up too tight. These days I never use mine, I use a cheap non slip rubber mat that stops the stone from sliding around when in use. Send me your address and I will send you some.

[Jim Bress]

Thanks everyone for you comments!

 

When mine crack, I usually create special shaped mini-stones from the bits for gouges.

 

They are not, to my knowledge, repairable. They will crack if they get too cold, as in freezing.

 

When they are dry, it doesn't take too much banging about to start a crack, so you may have just clilnked it against another ston or a bench, or i have even had something like this happen from a slip with a blade that gouges a corner.

I've had that corner piece, missing from the photo, set aside to use as a slip stone.  I have "clinked" my stones from time to time.  Not very hard and my heart skips a beat when it happens.  It's a shame if they are actually that fragile.  I moved last November.  Maybe it got damaged in the move, but the weakened structure didn't reveal itself until recently. 

 

I broke a corner off of a waterstone once, years ago, and glued it back on with polyurethane glue, e.g., Gorilla Glue. It's still holding together years later. I don't know if it's relevant, or even if it's the correct procedure, but I always dry my stones when I'm not actually using them.

I found this article by Chris Schwartz http://www.popularwoodworking.com/woodworking-blogs/chris-schwarz-blog/repair-a-shattered-sharpening-stone.  Repairing the stone is worth a try.  Whether or not the stones should only be submerged to prepare them for use, and then allowed to dry is something I've been wondering about.  Does anyone else have input waterstone care and maintenance?  

 

That yellow stone looks a lot like a fine Japanese stone. If so they are usually excellent. I have used Japanese stones for at least 20 years for all my sharpening requirements. The fine ones are quite soft and especially fragile when they are thin. If knocked they do break quite easily. If the break is clean, allow the stone to dry out completely and simply glue it with a two component glue. (I have never used Gorilla glue, but I am sure Mark is right.) If the stone is cracking in several places, I would consider sending it back to the manufacturer. I am a big fan of sending stuff back. Not to get a replacement or money back, but to help them put to things right if possible. If I had a problem of this nature I would want to know about it.
However, if the stone was (is) thin, consider using the bits as Duane suggests and get yourself a new one. There is nothing quite like unwrapping and using a new stone for the first time.

It is indeed a fine Japanese stone.  It cuts fast and leaves a mirror finish.  It is also quite expensive, which I justified the cost because I expected it to last 20 years not 2. it is still very thick so I will try to repair it.  After reading your response, I emailed the retailer's customer service to make them aware of the problem.  If I hadn't just bought a bunch of wood (tops, backs, and fingerboards) I would give myself a new stone for Xmas.  Instead I'll think I'll give myself a tube of two-part epoxy.    

 

Hi Jim,

 

It looks to me like the support for the stone, which appears to involve a clamping system, is putting undue stress on the stone. Mine are glued down with epoxy to a piece of marine plywood that has been varnished several times over with a water resistant boat varnish. The stones can be leveled against each other and can be worn down until they are paper thin.

 

If the clamping system is putting an uneven stress on these delicate stones you're guaranteed to get cracks.

 

There are a lot of cracks to re-glue but if you can get everything back together it would be good to glue it down to a non-deforming surface where it is held without building in any stress.

 

Bruce

I've wondered about the stress from improper support.  I have also seen some higher grit waterstones that come bonded to a support.  Which makes me think these higher grit stones may be more fragile.  I have some 3/4 ply scraps laying around that I can use for a support.

 

Bruce is probably right about the clamp. Although this is the 'official' clamp for Japanese stones. they can be done-up too tight. These days I never use mine, I use a cheap non slip rubber mat that stops the stone from sliding around when in use. Send me your address and I will send you some.

I don't think I've ever over tightened the clamp nuts, I usually don't use them.  Are you talking about the perforated rubber mat stuff you line your kitchen drawers or tool boxes with?  if so, I probably have some.  I'll send you a PM with my address. The postage might cost more than the material if I can just pick something up at Home Depot.  So no need mail the mat, but a Xmas card from Germany would be nice. 

[Roger Hargrave]

 Are you talking about the perforated rubber mat stuff you line your kitchen drawers or tool boxes with?  if so, I probably have some.  I'll send you a PM with my address. The postage might cost more than the material if I can just pick something up at Home Depot.  So no need mail the mat, but a Xmas card from Germany would be nice. 

 

Yes that is exactly the stuff. I use it all the time in the workshop. It also stops me falling off my chair when sleep overtakes me. 

[Jeffrey Holmes]

I use Japanese water stones myself..  have for decades.  I did chip one because I was a klutz one morning, but I never have lost one to cracking.

 

I sharpen on a marble castoff (flat piece of countertop).  No clamps, stands or stops.  As long as your stones are flat, a wet one will stick to the marble quite well by the suction created when you place it there.  Hope this helps.

[David Burgess]

Yes that is exactly the stuff. I use it all the time in the workshop. It also stops me falling off my chair when sleep overtakes me. 

Great idea! I had been using Velcro, but sometimes when I get up to answer the door, the chair stays attached.

[James M. Jones]

ouch! bummer.

When I got mine, the instructions said the coarse ones (mine go up to 800) , should soak in water when not in use. With the fine ones however, I have a natural and synthetic, it was suggested to let them dry in between uses, and to use just enough water to clean and condition with the narga stone.

[fiddlecollector]

Supposedly your not supposed to leave this particular stone submerged in water. The highest grit i use is a 12000 Naniwa superstone ,which i just splash a little water on before use. Or use  the narga stone first as mentioned above if it gets glazed.

I have to admit i prefer to use just a Norton double sided (4000/8000) stone most of the time.

[Michael_Molnar]

Supposedly your not supposed to leave this particular stone submerged in water. The highest grit i use is a 12000 Naniwa superstone ,which i just splash a little water on before use. Or use  the narga stone first as mentioned above if it gets glazed.

I have to admit i prefer to use just a Norton double sided (4000/8000) stone most of the time.

I have that Norton stone and LOVE it. It came in a plastic case that holds the stone securely.

 

I also have a leather strop for the final polish.

[DarylG]

Fiddlecollector is right that some waterstones aren't meant to be left submerged. I do know that the Norton stones are fine left submerged. I also have a Sigma 13K stone but I don't soak it. I only soak the coarser stones because the fine ones don't soak up much water and are basically splash and go. 

[fiddlecollector]

Another reason for cracks is if its in an unheated workshop (which some people do work in) if frost gets to them they can crack . Applies to all stones that absorb water.

[chungviolins]

Dry it completely (don't use for a few days) and glue them using super glue.

 

Or you can cut off making it smaller,I like smaller stone (flatter,relatively)

 

I use rubber sponge kind of foam underneath.

 

KY

[Janito]

This cradle came with the super stone I bought in Japan.

 

The stone sits between the 2 wood rails - simple and effective.  I dry it after use as the wood is uncoated.

 

ps - Apologies for the shadows - that's what happens when you have sun streaming in on 21 December.

[Davide Sora]

About glue the broken stone, I think that the line of hardened glue (superglue or epoxy) can damage the cutting edge during sharpening.

Has anyone noticed this?

Mine has broken into two pieces falling into the sink, I thought to glue but I preferred to keep them separated (using one piece at a time, of course) to avoid this problem.

Has someone tried to use a glued stone?

 

Davide

[Carl Stross]

  Whether or not the stones should only be submerged to prepare them for use, and then allowed to dry is something I've been wondering about.  Does anyone else have input waterstone care and maintenance?  

 

 

 

From what I was told by a heavy user, it depends on the stones. Firing temperature. I have 4 water stones and 2 seem immune to being permanently immersed. The other two have became noticeably softer and one problem with that is that they create too much slurry which rounds the cutting edge.

 

I quit using them in favor of synthetic Nortons used with light oil. My water stones were just not hard enough for the latest steels and the longer I sharpened, the rounder the edge had become. 

[Jim Bress]

I use Japanese water stones myself..  have for decades.  I did chip one because I was a klutz one morning, but I never have lost one to cracking.

 

I sharpen on a marble castoff (flat piece of countertop).  No clamps, stands or stops.  As long as your stones are flat, a wet one will stick to the marble quite well by the suction created when you place it there.  Hope this helps.

It's hard to tell from the picture, but the bench top (desk top) is covered by an 1" x 24" x 60" plate glass.  It's ridiculously heavy.  It creates a good suction with a wet stone, but I will scrounge for a cut-off piece of granite or marble tile so that a klutz event doesn't leave me with a broken stone and a chipped glass top. 

This cradle came with the super stone I bought in Japan.

 

The stone sits between the 2 wood rails - simple and effective.  I dry it after use as the wood is uncoated.

 

ps - Apologies for the shadows - that's what happens when you have sun streaming in on 21 December.

I like this cradle.  It is simple and elegant.  Pretty shouldn't matter, but sometimes it does.  I will probably make this cradle when the mood strikes me, i.e. because I'm putting something else off that I don't feel like doing.

 

-Jim

[MarkBouquet]

About glue the broken stone, I think that the line of hardened glue (superglue or epoxy) can damage the cutting edge during sharpening.

Has anyone noticed this?

Mine has broken into two pieces falling into the sink, I thought to glue but I preferred to keep them separated (using one piece at a time, of course) to avoid this problem.

Has someone tried to use a glued stone?

 

Davide

As I mentioned before, I used polyurethane glue to repair my broken waterstone. I chose it because it's extremely waterproof, strong and tough, and remains slightly plastic after curing, not brittle hard like CA or most epoxies. I haven't noticed any problem with it affecting the performance of my repaired stone. The glue line is very thin.

Jim referenced an article by Chris Schwartz about repairing waterstones. I can't access it because I'm not a subscriber, but I wonder what he recommends for glue?

[Jim Bress]

 

Mike, Fiddlecollector, Daryl, & Carl, You guys are probably right.  I believe the directions (where ever they are) said the lower grit stones (up to 3k) should be soaked for 5 - 10 minutes and the 10k stone could be just dampened on the surface before use.  Hind site, I should have interpreted the directions that if you have to soak the stone it is because you let them dry when not in use.  

 

Mike and FC, you both mentioned using a Narga stone.  Does a Narga stone make that much of a difference?

 

Thanks,

Jim

[James M. Jones]

Jim, I don't know how much difference they make ...( narga stone) ...I use it mostly to get a really clean surface on the stone free of any dust, also it seems the slurry made with it sort of helps things slip a bit . they might also help produce a graded surface to work on.

[Jim Bress]

KY, Davide, and Mark, I will dry it out completely and glue the missing corner back on with a polyurethane glue (maybe).  I'm not sure why the link to Chris Schwartz' blog didn't work for you.  It's works for me and I'm not a subscriber either.  He writes:

 

"The trick is, of course, a strong epoxy and a strong substrate to glue the pieces onto. I’ve glued stones back together on a chunk of white oak before and it worked just fine, but it looks nasty after a while because it soaks up so much metal slurry.

 

So I chose to use a solid surface material that’s similar to Corian. I have two chunks of this stuff left over after we installed new kitchen countertops five years ago. The countertop installers presented us these two chunks as a “gift,” complete with beveled edges." 

 

It sounds to me that he glues the pieces to a substrate with an epoxy glue, but does not glue the pieces together.  I'm not really sure.  Because my stone has not broken apart yet (except one corner), I can use an epoxy to glue the entire stone to a solid surface which should prevent the cracks from getting worse.  Maybe I can use the epoxy for the corner just near the substrate.  I'll have to think about it for the corner.

 

Thanks,

Jim

 

[MarkBouquet]

Jim,

Remember that polyurethane glue requires moisture as a catalyst for the curing process. It's recommended that you dampen the gluing surfaces while using it. So you don't need to be too worried about thoroughly drying the stone first, if you use polyurethane glue.