fissures in waterstone

[Noah Wagener]

I bought some of the Sigmas that Lee Valley carries about 6 months ago and one (10,000) has developed hairline cracks throughout. I epoxied it to some cedar but that has not really helped; i still feel the cracks. It has not been dropped or submerged for longer than an hour. It was left in a garage that got down to like 40 fahrenheit. Any ideas why this happened? It did not happen to the lower grit stones.

[george wilson]

First of all,I would never epoxy a fairly soft stone to a piece of wood. Wood isn't a very stable material. If it expands with the humidity,and the stone is securely epoxied to it,it could cause the stone to crack open. Plane the wood off carefully,and epoxy it to a plate of heavy glass. Get the glass cut to fit the stone.

[David Wong]

Same type of hairline cracks happened to me with my Naniwa Snow White 8K. I continued to use it for quite a long time, and there seemed to be no ill effects. I eventually became worried that there could be cross contamination in the cracks and stopped using it. Easy for me as I have a couple of other finish stones. I read online that the Snow White is susceptible to this "crazing".

If you cannot see any problems on your blades, then it is probably still good. One day I'll get around to more closely examining my Snow White stone.

[Chris Griggs]

Same type of hairline cracks happened to me with my Naniwa Snow White 8K. I continued to use it for quite a long time, and there seemed to be no ill effects. I eventually became worried that there could be cross contamination in the cracks and stopped using it. Easy for me as I have a couple of other finish stones. I read online that the Snow White is susceptible to this "crazing".

If you cannot see any problems on your blades, then it is probably still good. One day I'll get around to more closely examining my Snow White stone.

I've read this about the chosera's and the snow whites as well, but I've experienced nothing of the sort with either my snow white or cho 800...I wonder what causes it?

Have they ever been left in the sun or near a heat vent? Maybe drying to quickly would cause it?

[David Weaver]

The chosera (that archie has now) that I had would get very superficial marking on the surface, but you couldn't even call it a crack really, it was just like a pattern.

Is this SPII really cracked as in the cracks run deep and they're unstable, or is it just stable checking?

If you do glue stones to wood (which is something I do), it's best to use the straightest QS stuff you can find in a wood that is moisture tolerant.

[Stuart Tierney]

It's a manufacturing problem, nothing you did.

If the cracks start causing problems, let LV know. If it's not causing problems, then don't worry too much about it. Chances are it won't cause any problems, but it might.

Also, get it off that piece of cedar. Next time around, use a more flexible adhesive with a wood base, something rigid like epoxy with a stable base material.

These cracks occur during the firing of the stone, I can't recall the exact reason, but it's from the kiln. Inspection catches most of them before they go out into the world, but obviously not all of them.

Stu.

[Noah Wagener]

I think they are more than superficial but i am not really experienced. As to if they are causing problems; i'm not real sure there either. I am a real novice sharpener and it is kind of hit or miss for me getting a tool sharp.In my head it causes problems. I think i feel those cracks. In my head it feels better when i rub the medium stone on it and those cracks get filled with slurry. I bought these stones as an upgrade to the King combo 1000/6000 but i definitely got better results on that stone. The 6,000 just felt and looked cooler than this Sigma. It had a mottled color that looked natural and a sheen to it. To me, it even felt harder. I can actually gouge the Sigma with my fingernail.

Here is a pic of the cracks:DSCN0232.jpg

that big one is definitely worse since i let it dry out completely. Can these stones be perma soaked? whenever i feel the need to sharpen i hate waiting fifteen minutes. I come on here to kill the time and end up spending hours. Which of these: SHapton Pro, Chosera, and the other Sigmas that Stu carries can be left in water?

And can you guys explain the difference between ceramic stones and ceramic water stones?.How do those Spyderco stones not wear at all and remain sharp? I tried to return a diamond stone to Woodcraft after it finally dawned on me that it had a valley to it. It would put a hump to the backs of blades. They wouldn't return it for being unflat but gave me a new one because it was so blunted. The new one was dulled very fast as well. If diamonds can be so short lasting, how can clay last indefinitely? And the ultra fine is listed as 1,800 grit. Is that the one you use George?

I put cedar on the bottom because i recalled Chris Schwarz writing about fixing a cracked stone by gluing to wood. I thought cedar was a moisture resistant wood? Maybe I'll glue it to the medium stone?

p.s. George, did you see the comedian Tracy Morgan at Williamsburg. He references it so much in diverse settings that i think he might have even worked there.

[David Weaver]

That's more than superficial, return it.

Spyderco's ceramic stones are made by coors ceramics. They are a solid ceramic like you'd think of with a coffee cup, though the medium grit will soak some water (and can be used dry, anyway).
The other ceramics you're used to looking at are resin bound ceramic, magnesia bound ceramic, etc, the abrasive is ceramic alumina, etc. I think ceramic gets thrown around a lot for modern stones, but they are made with various different processes. In general, if you see the term ceramic, it should imply that the stone has some sort of hard and durable abrasive in it. Spyderco doesn't use the same grit scale as the JIS scale stones (shapton, naniwa, etc), and the structure of the stone itself is different. Consider the spyderco to be a stone that can do something like any other 10k grit labeled finisher.

Most of the resin and magnesia bound ceramic stones are easier to use than the spyderco stones and faster. The UF spydercos do break in and have a duller feel when they do,they cut like mad when they're brand new, but you won't see that cutting speed again if you don't abrade them with diamonds (and you won't seriously abrade them with anything else). When you clean them with a pot cleaner like they suggest, they get some refreshed cutting back.

Stu's sigmas can be kept in water indefinitely, king's red stones can, besters can, choseras no, and shapton pros, no.

If your sigma is an SP II sintered stone, they're soft, that's just the way they are (based on the comment about being able to dig in a fingernail).

Anyway, cost-wise if you want nice stones, the shapton pros and the sigma (not the sintered soft type) are probably the two choices for all around use. If budget counts, I'd use a bester 1200 and pretty much any finishing stone to go with it (naniwa snow white, shapton pro, SPII) and minimize the amount of metal the finish stone works by using a micro bevel.

Choseras need to be soaked for a short period of time to have a nice action, but they can be damaged by long soaking. Shapton opinions may differ (about whether or not they should be soaked) because they have some stiction for a beginner when they're not soaked, but I like them much better not soaked because they are hard and you have more control over what they do (in terms of whether or not they shed grit) as a user. Any time they seem to be glazed, short strokes up the stone with water will remove the swarf, and if the abrasive is tired, a quick refresh with a diamond hone works them back to fresh and fast cutting. I haven't had stiction issues for at least 5 years and never soak them. As a hard stone user, I consider them quite nice (they are my overall favorite), and they are definitely a lot easier to use than a hard natural japanese finisher - by leaps and bounds. Stu mentions from time to time that the instructions say to soak them but I've never talked to a long-term user who actually does it.

The SP stones (I've only used the 1200 and 13000). The 1200 is like a refined version of the bester 1200 (not to discount the bester 1200, I like it a lot), and the 13000 is somewhere between the non-porous shaptons and the old stones for feel and grit shedding - it will soak up some water and works better if it's been soaked, and it will release some grit. It is the finest cutting of the relatively inexpensive stones and makes a bright polish.

All of these are probably a little easier to use in the long term than the spydercos.

Side comment about the choseras, if you're willing to babysit them for 15 minutes, they have the nicest super slick feel and cut fast. But if you don't like to wait on a soak, they're not the way to go - and they're expensive (because naniwa says so, not because they have to be, as there have been unbranded magnesia stones from time to time with the same feel that have been dirt cheap). they don't have the same magical feel if they're just splashed.

[Stuart Tierney]

Hi Noah,

That is not right at all. The crack is incredible (I've never seen anything like that before) and that stone must be returned. My own Select II #10000 here cannot be gouged by a fingernail, so it's also super soft and again, not right.

While I really shouldn't be doing this, as it's not 'my' stone, I have to ask if the stone had cracks originally and was it as soft as it is now when you first used it? Basically, what has changed since new and by how much have things changed?

These stones can be stored in water, but it's not necessary and while Sigma Power says it's ok, that is unofficial. They don't need to be soaked and work the way they were intended with a splash of water before use. My concern with perma-soaking is that I can see where you live, and I know it's cold there, so I wonder if the stone has been in water, and the water has frozen? If so, that will certainly bring out any cracks that might be present (and otherwise missed/ignored) or weaken a stone that can't handle freezing to the point of failure. Actually, not too different to what that stone looks like...

Please, some more details about what might have happened to that stone or if it was like that from new.

Also, please wait for a perfect stone before making a judgement whether to try something else. The Select II #10000 is actually very good and you may find you do not need to try anything else once you have a good one.

Stu.

[Noah Wagener]

Stu,

I did not know the stone was a splash and go stone. Lee Valley has generic water stone care and it did not come with any instructions. I e-mailed them about leaving them in water while i worked and they said that was ok with the 1,000 grit only and to soak the others 10-15 minutes before use. I'd have to wait on the higher grit stones anyways so i do not leave the 1,000 stone in water.

The stone did not always have those cracks. They started about a month and a half ago which was about 4 months after i got it. As to if it was always that soft i can not really say. It did slurry up real fast if that is any indication. It is more of a scratch than a gouge i can do with a fingernail.

The stone has not been in water that has frozen. It did get near freezing in October. The stone was not in water but probably did have water in it though it was out of water for week during those cold days. That is when the cracks started to appear.The other 2 (1,000 and 3,000) have had exact same treatment and are fine. The cracks expand the longer it goes without water like parched earth.

I hear you about giving the stone some more time before passing judgement. I just can not get the pretty mirror polish i was hoping to with the jump up from the 6,000 King. The edge has a matte look to it. Can you get a polish with Select IIs? Maybe polish isn't that important? I read a lot on sharpening and stones but the lingo and my lack of experience are a block. I never sharpened anything but pencils until the last couple of years. Once bought a set of chisels because the set i had found in the garage was dull. So i definitely need to improve my technique before choosing a stone. But from i read on here experienced people prefer harder stones. It looks like i'm going to need a new fine stone so i think i'll get what the experts here use if i do. David has enough stones to keep out Mongol invaders and it seems he doesn't have these so that tells me something. If i felt comfortable returning it i might try the new one for longer but i don't.

I wish i would have seen that 3 stone plus the Atoma diamond plate deal you have before i bought these.

Thanks for help, Noah

[Stuart Tierney]

Hi Noah,

Based on what you're telling me, I'd have to say that it's most likely that the stone did have water in it, and it has frozen and started cracking the stone, causing both the cracks you can see and the softness of the stone.

(My own Select II #10000 is 'hard', not 'very hard' but 'hard' and I can't put anything more than fingernail remains on my own stone.)

The #1000 and #3000 are more porous, and are likely to have dried out before any real damage could have occurred due to freezing.

As far as a polish from that particular stone, pre-cracking, very much possible. Soaked, it will tend to leave an unpolished finish, but the edge should still be very sharp. Splashed with only a little water before use, the edge should polish up nicely.

(A polished edge being sharp is possible, a matte edge and being sharp is equally possible. A polished edge however may not necessarily be 'sharp', contrary to popular belief.)

I'm sorry, but I think the stone is kaput, and it's not due to a manufacturing problem. Yes, some of these stones have come from Sigma Power with small surface cracks in them. I've never seen them bad enough to affect performance, but enough to replace them under warranty. I don't know if it makes you feel any better, but it's quite likely that most stones would be similarly affected by being allowed to freeze with any moisture still in them.

(I have frozen several stones to see what will happen, not all stones fall to pieces when frozen.)

I don't know what else to say here, other than I'm sorry that your stone seems to have died not through anything intentional, just accident. I'm also unhappy that you never seemed to get the best from the stone before it's apparent demise. It's a good stone, perhaps not as popular as it probably should be, and typically quite easy to use and very effective in getting the job done.

Stu.

[David Weaver]

It's not unlikely that if it's glued to something, you can continue to use it dry if it's a little soft. If you're in a shop where there's a chance that future stones may freeze, even if it's due to them being partially dry but out of the bucket already, I would go with shapton pros, oilstones or a diamond setup.

I have a cold shop, too - but not minnesota cold. I haven't used waterstones with much frequency for the last 6 months because of a detour of fascination with washita stones, but when I did use them, I hung up all of my soakers for the winter and my shop generally doesn't get colder than mid 40s. Even at mid 40s, a soaked stone is extremely undesirable to use and dunk in water, etc. Folks less sensitive to 45 degree water than I am might be less bothered by it.

I did have a 3k sp II that I used more or less as a replacement for a tanba aoto. I love the tanba aoto stone type, but they fall apart too fast and their mud is like slick grease - they are a sloppy mess. The SP II was better as that role, but I sold it to another creeker because I kind of set my japanese planes aside. The IIs are a very specific stone. The shaptons and the SP set that stu sells are a more generalized stone. What the SP IIs of the sintered silicon carbide type do is better done by diamonds, and the compromises they have to do what they do well are what some people like (a fresh softer stone) but are something I don't like. Since the aoto that I was used to is already soft, and since the SP II basically is a better syntehtic version of it, I did like it in that role (the aoto is a transition stone that is fast and loose and that gets you ready for a finish stone).

I couldn't tell you what most pros, do, though - I've not met any around here who actually use hand tools. The rest of them I've seen online adopted their sharpening regimen long ago (George for example, who uses the hardest stones you can find) and they may or may not choose differently if they started now. Either that, or they're semi pros more focused on teaching and selling, and they use something they sell. Quite often what's sold by demonstrators is influenced by whether or not someone already sells it. For example, shapton isn't going to give LN the north american market, because Harrelson Stanley is already the distributor for at least the United States, and dealers from japan are supposedly selling you "gray market" shapton stones, but in my opinion, the commentary about how different the stones are has a lot more to do with shapton protecting the distributors than there being a huge difference between a shapton cream from stu and a shapton 15k pro that goes through stanley.

Anyway, if you do much carving (or any) you'll definitely need to have harder stones - shapton pros would be borderline for that, and most people would consider them hard. I'd consider them a medium hardness stone because you can still scratch them with small pointy things. A medium hard stone would be something like a soft/hard arkansas, a hard japanese waterstone, etc. and a straight up hard stone would be something like the spydercos. Most people who just use waterstones would consider shaptons (other than some of the coarser stones) hard.

Stu and I definitely like different things in stones. That's already apparent. Luckily he's busy for the last year or so, that keeps us from arguing back and forth in emails.

[Winton Applegate]

I have never understood the need to glue a stone to a hunk of something.
If you don't then you have two sides to use. I have one side I use just for blade backs and finish plane blades and the other side I let go a little longer before flattening and for chisels.
To glue the stone to something is to eliminate 50 % of the useful surface of the stone.

A sheet of hard neoprene and a mist of water between the counter and the mat and between the mat and the stone is all it takes to hold the stone to a flat smooth surface. Slide the mat around and it will suck down and stick and then the same with the stone. Pivot the stone on the same plane as the surface to release it.


You can see where the stone was sitting . . . about that much water or even less.


As if by magic.
(the simplest solution is the hardest to arrive at.)

[Noah Wagener]

Thanks for the sympathy Stu. Your customer service must be excellent. I feel like i bought it from you.

Do the coarser stones not require a soak either? If I put a little water on top it gets sucked up immediately. I was told to soak until they stopped releasing air. I tried the splash method on all 3 and i definitley wish i would have known that with the 10,000 as the edge was at least more aesthetically pleasing. Maybe it would have dried out before it froze too.

I definitely think i prefer hard stones. If lack of forming a slurry is an indication of hardness. The king 6,000 i mentioned can be left in water indefinitely and nothing ever forms on top. I thought they were supposed to be some of the softest stones?

Are their different techniques for different types of stones? I see some people who only push a tool and some who only pull. Some go both ways but will start to only pull on finishing stone. People opposite things bout how much pressure to apply as well. I wonder if that is because of the stones they are using and don't know that their advice is not going to work on other stones?

I feel sharpening is a real gateway skill so I read about it almost exclusively but i think it becomes more mystifying the more i read. I was just reading a post on a straight razor forum where a guy said he likes to follow the Chosera 10,000 with his Norton 8,000 because the edge off the Chosera was too "crisp". That really boggles my mind. Why would someone pay 250 for a stone and then regress the edge? Why not just stop at the Norton then? Surely for woodworking you want the smoothest edge? Someone in those planing competitions said he does the same thing, going to coarser stone. He likes a little tooth to his edge.

Winton, where can you get rubber like that. I was looking for something like that at places like Menard's. All I could find was floor mats and shelf liner type stuff. They were too hard or something so i ended up building a sink bridge but the reach is uncomfortable. Is it similar to a bike tube?

[Jessica Pierce-LaRose]

At a couple of the local Ace hardwares they have smaller sheets of neoprene (still large enough for a stone or two) sold over by the plumbing supplys as raw material for making gaskets. You could probably talk to a roofer and see if you could get an off-cut of the rubber underlayment they use on the edges of roofs - my neighbors got some of that stuff he uses for a few things.