12 April 2018 at 1:23 pm #522750
I’ve been flattening the backs of some troublesome tools recently and it has been taking forever. Years ago, I put away my water stones, when I switched to Paul’s diamond plate method. For no good reason, I got out the 1000 grit water stone, flattened it, and gave it a try for flattening my blade. Wow. I had forgotten how quickly these things cut! I made more progress in 50 strokes than I had made in 30 minutes with a DMT extra coarse (220 grit?) plate. It was even faster than sandpaper. Yes, it needs to be reflattened ever 20 to 50 strokes, but I think I’m going back to water stones for flattening tools, since I own them. Diamonds are nice because there’s no fuss, but I’m guessing that the plates don’t have much grit on them compared to sand paper or water stones, and that makes them slow for removing large quantities of steel, which is what happens when flattening the backs of tools.
Here is a summary of what I’ve experienced flattening backs:
1. Diamond plates- Stay flat, no fuss, but unbearably slow for flattening backs. I think this makes me go to coarser and coarser diamond plates until I end up flat, but with deep grit scratches and bug-eyed crazy from how slow it was.
2. Sand paper- A lot of grit, cuts quickly, but paper fails quickly, too. If you don’t glue the paper down, it will dub the edges of the tool. If you glue it down, it still might dub the edges. When I go from coarse paper on a granite block to a finer grit on a diamond plate, I usually find that the two surfaces do not register. So, the diamond plate will polish spots here and there, but lower areas remain scratched from the sandpaper. I can work through this, but it takes a long time. This is despite working on a supposedly flat granite reference plate and using spray adhesive.
3. Water stones- A royal, messy pain in the butt, but they cut quickly and give a uniform scratch pattern. They will be out of flat in 20 to 40 strokes (depends upon the particular stone). I can remove metal with a finer grit vs. paper or diamond. (Finer means microns. I’m understand there are different grit scales.)
I know many people report being able to flatten and polish the backs of tools in just 5 to 10 minutes, but that has never been the case for me. It takes me much, much longer.12 April 2018 at 7:18 pm #522914
In the same boat. I got replacements for my DMT stones which failed under warranty, and they’re already very slow, even though they’re relatively young and I’ve never used much downward pressure at all on them.
I can’t have sharpening and flattening seem like such a chore, because then I won’t do it enough, and that will ultimately bring down everything like a house of cards.
So I mentioned that to a professor of mine at the woodworking college. She’s a former student of Krenov’s, and works primarily with hand tools. Even though she’s super busy (she’s in two different exhibitions right now, and teaching), she challenged me to bring in two dull chisels or plane irons, and sharpen one with her collection of water stones, and the other with my DMTs.
There was no comparison. Her stones were far, far faster, and the finished edge was superior, although I can’t quantify by how much. Her stones also yielded a far superior polish than the diamonds, the utility of which I can’t quantify, but I hope to google around on that topic eventually.
So I switched and bought the same stones. The mess has been controllable, albeit just barely. The larger hassle is having to soak some of them, even if it’s just for a few minutes, so I can’t sharpen right *now*, I have to wait for 3 minutes for a few of the stones, and then re-flattening them regularly. Stropping often during the project helps quite a bit, so I’m OK with the hassle of new system, and very happy with the improved results.12 April 2018 at 9:36 pm #522988
@etmo Out of curiosity, what stones does she / you use? How are you flattening them?
Are you still using a strop, or are you using a super fine water stone to take the burr off? You said you touch up with a strop, but I’m wondering about what you do when you sharpen?12 April 2018 at 11:19 pm #523026
@ed — she uses (and now I do, too) a combination of the Naniwa Professional Series and the Sigma Select 2. The SS2’s are amazing, you use them and steel just flows off your blade. They dish and flatten back up super fast. They leave a matte finish and their edge is pretty darn good if you go to their highest grits. The Naniwa Professionals leave a mirror polish and an excellent edge, and neither dish nor flatten as quickly as the SS2’s.
So the SS2’s are the low grits, then the Pro at the end for that great edge and polish.
I’m flattening them with my DMT coarse stone. Mark them up with a pencil. The SS2s take about 10 seconds per side…I do 5 seconds, then re-mark the pencil lines and rotate the stone 180 degrees to hopefully ameliorate the many flaws which doubtless exist in my flattening technique, 5 more seconds. A couple of times I have needed 10 seconds x 2 (when 5 seconds doesn’t remove all the pencil lines), never needed more than that yet. The Pros take 30 seconds a side, give or take.
I should note that all the bevels are hollow ground, so ymmv, but it goes like this: 5-10 strokes or so on the 3k SS2. Then 10 or so strokes on the 6k SS2, and 10 on the 10k SS2. Finish with 10-20 on the 10k Pro. The 3 minutes for the SS2’s to soak is far longer than it takes to actually sharpen a blade, so I usually wait until I have a handful of edges to sharpen, soak, do them all, and that will usually dish out both sides of the SS2s to the point where I’m justified in flattening them, and since they’re soaked, they’re ready to flatten. Wipe them dry and they all get stored dry.
She has a 240 and 400 grit SS2 for flattening backs and changing bevel angles quickly. I haven’t used them yet. When doing rougher work like hogging out mortises, she’ll often go back to work straight off the SS2 6k, but for establishing the edges of a mortise, the edge always gets the full Monty.
So I’m following her example wrt stropping, and only using it to touch up. Pulling burrs off with the 10k Pro after sharpening.
Often what’s good for someone of exceptional skill and talent is not optimal for a hobbyist hack like me (for example, she sharpens by hand like Paul and recommends it to others; no way I’m leaving my Mk2 jig, even though she calls it a “training wheel”). But so far this system has improved my edges and does have me spending less time sharpening (even adding in the high frequency of stropping).
Oh, I get some of the SS2’s at LV (woodworking college gets us a discount there), but the Naniwa Pros and the rest of the SS2s are from https://www.fine-tools.com/naniwa-chosera.html and https://www.fine-tools.com/sigma.html. I get them there because LV doesn’t have a complete selection of SS2 grits and because it’s often difficult to differentiate between the middle-of-the-road “Sharpening Stone” line from Naniwa (https://www.fine-tools.com/naniwa-stones.html) and their Pro line (link above). If you look around Amazon, for example, you’ll quickly see how misleading some sellers can be (perhaps by accident, IDK).13 April 2018 at 12:05 am #523051
@etmo What an interesting coincidence: That’s pretty much what I have, but mine are the Sigma Select 1000, Sigma Select 6000, and Sigma Select 10000. If you are curious, I contacted Sigma to learn the grit sizes, which turn out to be 10, 1.5, and 0.9 microns. I’ve been using the Sigma Select 1000 for flattening, as it is the coarsest that I have.
I’m using a DMT lapping plate to flatten them, but it takes me much more than 10 seconds. I get about 20-40 up-and-back strokes on the 1000 before flattening, which then takes about half a minute, maybe a little more. I don’t use much pressure when working the tool or flattening the stone. Perhaps my time is longer than yours because I’m just working the edge of the stone and have a big hump in the middle to get rid of.
In the past, I’ve used Paul’s diamond sharpening, but then used the 6000 or 10000 to take off the burr. I tend to make a large burr and have trouble getting it off, so that’s why I tried that. In other words, I can’t do Paul’s “just a quick pull on the superfine.” Instead, I must work the burr back and forth on both the bevel and back, so I lose the polish on the back of the blade. So, I’ve played with different options for the final, high grit stone, one of which was the water stone. In the end, it was too much of a bother to flatten the stone, so I tried one of the DMT extra extra fine stones, which is supposed to be 3 microns. That thing leaves horrible scratches.
Unfortunately, this isn’t all theoretical. Tuning my sharpening has improved my work. I seem to go through cycles of making it harder, but better, and then simpler.
Do you think you could skip taking the burr off on the 10000 and get it off on the strop, instead?
Oh! Be careful. I’ve used Paul’s method on water stones, but it is REALLY easy to gouge the stone. If you try it, you may want to only do pull strokes. So, make sure to get down off the edge, towards the heel, then push forward. Only reach the edge on the pull. Or, just pull, lift, pull.13 April 2018 at 5:25 am #523203
If you are curious, I contacted Sigma to learn the grit sizes, which turn out to be 10, 1.5, and 0.9 microns.
That’s great info, thanks, and seems to jibe with the results I see. My other professor has contacts in the woodworking community in Japan, I’ll ask him if he can get us micron sizes for the Naniwa Pro stones.
I tend to make a large burr
That’s interesting. Mine are such delicate little things they come off with no effort at all, and yes, I have removed them on the strop, both after sharpening and after stropping. The moment your burr is along the entire edge, is it already large, or do you tend to sharpen for a while even after you have a full-length burr? I’m wondering what might cause the difference in sizes.
Lastly, when you say, “Paul’s method on water stones”…to which of Paul’s methods do you refer? Maybe you’re referring to the way he scrubs back and forth? Thanks for the word of caution. Since switching, I have only been pulling. If I start scrubbing, I’d remove more steel than necessary since it comes off so quickly, and I seem to get a more complete burr more quickly from pulling only. When I used to scrub on the diamond plates at the finer grits, the burr would sometimes get ground into powder and I’d never see it, so I’d keep going, which is a feedback loop of the time-wasting variety.
So I started applying pressure on the pull only after I’d felt I’d been scrubbing “long enough”. Thankfully the water stones are so much quicker that my patience never gets tested anymore, and I can keep a more disciplined approach.13 April 2018 at 12:49 pm #523600
You got it- “Paul’s method” means “back and forth,” although I guess that’s not really a method.
Large burr- I suppose the empirical thing to say is that I have trouble removing the burr, which I interpret as a large burr. I believe that is right, but it could be a flattening problem. In Paul’s method, which I tend to use, you always go back to the coarse stone, and that’s where I think it happens. I’m just grinding too long.
Does the Naniwa produce a shiny, mirror finish? Unreliable links on the web suggest its grit size is about the same as the Sigma 10,000. I find the 10,000 doesn’t give a shiny mirror finish, but gives a lustrous satin. If I look at it with a loupe, I can barely see the scratches. The reason I’m asking about the Naniwa is that I’m suspecting that the same grit sizes but in different substrates or different type of particles gives different appearances. I’m also suspecting that the revered, “shiny like a mirror” is not a good measure and isn’t always necessary. This stone at less than 1 micron is, without doubt, giving more polish than lasts for the first couple of shavings. Even the 6000 at 2 microns is likely flat enough and polished enough…it’s 3 times finer than hard Arkansas.13 April 2018 at 4:28 pm #524190
Does the Naniwa produce a shiny, mirror finish? Unreliable links on the web suggest its grit size is about the same as the Sigma 10,000. I find the 10,000 doesn’t give a shiny mirror finish, but gives a lustrous satin. If I look at it with a loupe, I can barely see the scratches. The reason I’m asking about the Naniwa is that I’m suspecting that the same grit sizes but in different substrates or different type of particles gives different appearances. I’m also suspecting that the revered, “shiny like a mirror” is not a good measure and isn’t always necessary. This stone at less than 1 micron is, without doubt, giving more polish than lasts for the first couple of shavings.
No question on the mirror from the Pro 10k. Big difference (at least optically) from the SS2 10k, and that’s why she uses the SS2 10k then follows it up with the Pro 10k – the SS2 will remove whatever scratches a 10k removes very very quickly, so the Pro 10k can do it’s job much more quickly because the table has been set, so to speak.
As to different substrates producing different appearances — no doubt. Our school has a relationship with a similar school in Japan, and cultural exchanges will regularly take place. So we had a visit from some of their teachers not too long ago. Every morning they’re up sharpening their tools before work, and one of them, who is their sharpening instructor, finishes sharpening with a highly prized natural stone quarried in Japan sometime in the 19th century which has been in his family for generations (He is the son, grandson, great-grandson and great-great-grandson of a woodworker). The stone was about the size of a dinner plate, and valued in the tens of thousands of dollars, which blew my mind. It has produced edges that have won competitions in Japan. His tools have no mirror to speak of. They are all — your word choice was excellent — lustrous, but not blingy shiny. When I asked their translator to ask him about the lack of mirror, the relayed response was that a matte finish is typical of a number of natural stones in Japan quarried from certain regions.
Interestingly, all the other Japanese teachers had mad crazy mirrors on all their tools. I remember one of them was sharpening a good-sized flat chisel. He’s carefully going along his final stone, almost seemed asleep. He was at it for a while, and I sympathized with that! One of his colleagues called him over, and he got up — and his chisel stayed exactly where it was. It was stuck to the stone by the vacuum/capillary action/whatever force against the bevel alone, and 9 inches of chisel were just sticking out at a 30 degree (or whatever) angle from the stone. When he returned, he freed his chisel and inspected the bevel, and it had the shiniest mirror I have ever seen on any tool.
I’m also suspecting that the revered, “shiny like a mirror” is not a good measure and isn’t always necessary.
I agree. Ron Hock’s definition of sharpness does not include any words like “mirror” or “shiny”. Now when metal is very very flat, that uniformity of surface does tend to reflect light in a consistent way, so there is some correlation there. And as the surface of the metal goes to finer and finer grits, that reflection of light gets more and more efficient, so I totally understand where the “mirror is good” thinking originates. But if Japanese edge competitions have any merit in this discussion, a matte finish can be the sharpest edge, as demonstrated by natural stones sometimes winning that competition.
I should note that my professor claims the resulting edge is superior on the Pro 10k, and perhaps that has biased me into believing it. I certainly have nothing quantifiable to share on that front other than to note that the hardness of the Pro 10k is much higher than the SS2 10k. I did email my other professor asking about the Pro series grits, so we’ll have an answer, probably straight from Naniwa, before too long.13 April 2018 at 4:43 pm #524217
@etmo If you ever find the opportunity, perhaps you could ask something for me? I have always wondered whether the Japanese craftsman 100 or 200 years ago fussed over flatness so much. They wouldn’t have had these goofy, machined, ‘flat to 0.0005″‘ diamond plates. So, what did they do? I’m guessing there are ways to sharpen with these soft Japanese stones that doesn’t require constant flattening. It is probably a mixture of understanding what to do, understanding what matters vs. what doesn’t, and learning to wear the stone somewhat uniformly, but probably not perfectly. The only way to really ask the question is to find someone senior with reliable provenance through a teacher’s teacher.
Do you know if Japanese traditional sharpening used a strop?
Once or twice a year, as my experience grows, I loop back through my tools to reflatten and overall re-fettle them. That’s what’s happening right now and is why I’m so keen on sharpening at the moment. Most of my planes are redone. With luck, I’ll finish today.
I should add: It seems important to remember that the tool must match the wood. So, if the Japanese tend to work in softwoods and we work in hard, some of their methods and tools may be completely inappropriate, whether it is steel hardness or bevel angle or some other aspect of the tool.13 April 2018 at 8:21 pm #524675
@ed — definitely will ask; I’d be interested to know those things as well.
oh, and no, never even saw a strop in their possession. Admittedly a small sample size, so FWIW.15 April 2018 at 2:13 pm #526339
The larger hassle is having to soak some of them, even if it’s just for a few minutes, so I can’t sharpen right *now*, I have to wait for 3 minutes for a few of the stones, and then re-flattening them regularly.
@etmo I keep forgetting to ask, can’t these stones be stored in water so that they are always ready? That’s what I do, when I’m using them. Two of my stones came with bases, one plastic and the other wooden. Living in a tub of water won’t affect the plastic base, and too bad for the wooden. If it rots and falls off, all the better. I use the cheap Glad tubs the grocery store. A smaller one holds the 1000 and the next size or two up holds the 6000 and 10000. Sometimes I wonder if the loose grits can cross contaminate, but after a minute I remind myself it isn’t telescope grinding and the feeling goes away.
Also, I have a better answer for you about what I meant by “be careful with the Sellers method on water stones.” I think the traditional Japanese sharpening is done on irons that are thick and have flat bevel, not cambered. Don’t they register a flat face onto the stone and keep it flat? That’s why the sharpening master could stick his chisel to the stone. (No one likes a show off.)
In the cambered bevel approach, though, at the end of the draw stroke, ideally you are on a perfect line of metal, not a facet. There is no registration. It’s generally not a problem and the situation has a distinct sound and feel that gives feedback when sharpening. Learning to hear and feel that removes a lot of uncertainty from freehand sharpening.
The problem is that, if you hit that line and then give even the slightest upwards wiggle to the handle as you start the push, the blade will dig in. For a diamond plate or india stone, it won’t matter. If it is a little wiggle, you’ll just feel a little resistance and will get a trivially steeper edge. If it is a bigger wiggle, you’ll “trip,” and it will seem like the handle goes tail over kettle. On the water stones, though, these trips seem to happen more easily and, when they do, you can gouge the stone.
My water stones aren’t precious, so I don’t worry too much about a nick, especially since over time it will wear out. I find that with a very light touch, I can make the cambered edge method work on the water stone, but I definitely get catches now and then. If in doubt, though, just do draw strokes to the edge.15 April 2018 at 4:27 pm #526426
I keep forgetting to ask, can’t these stones be stored in water so that they are always ready? I keep forgetting to ask, can’t these stones be stored in water so that they are always ready?
@ed — So the Naniwa Pro’s are like any magnesium-bound stone, you definitely cannot store them in water for any prolonged period. However, they don’t require soaking to work, they’re in the class of “splash-and-go” stones where you just put some water on them in their bone-dry state and they are ready to work. However, the SS2’s claim no binder, so maybe you’re right, and that brand can just be left to soak forever. If you’ve been doing it with no issue, I’ll follow suit and be very grateful for the tip.
Interestingly, my SS2s didn’t come with any base whatsoever, but it sounds like a nice accessory if you got it for free. “Rots and falls off”…do you mean to say your stone is somehow bound to the wooden base? I must be misunderstanding you…if your stone were, say, epoxied to a base, you couldn’t flip the stone over when one side was dished and use the flat 2nd side.
You’re right about traditional Japanese sharpening, at least as I understand it. The cambered technique you’re describing — I have been plagued by doubt in my sharpening technique, hence the jig and draw strokes, but your description is good enough to make me want to test it out.15 April 2018 at 5:00 pm #526452
@etmo I think we’re using different stones after all. Mine are not the Select II, but are the Sigma Power Ceramic. See, http://www.toolsfromjapan.com/store/index.php?main_page=index&cPath=335_404_403 . It doesn’t look like Stu sells the 6000 anymore, although he sells a set that includes it. So, I don’t know about soaking all the time or not for what you have.
The best thing to do would be to contact the manufacturer. I found Sigma to be responsive, at least when I contacted them 5 years ago. I used the email addres, [email protected] , and I still see that address listed on a web page for the SS2, http://www.saicom.info/english/ . If you contact them, let me know what you find out!
I just reread Stu’s web page about the stones I use and says there that they don’t need to soak, but just need a spray. Well, in other places, I think he’s said the soaking the 6000 is good, so I’m not sure which. Yes, the bases are bound to the stone, so you can’t flip them. I think I’ll stop soaking the 10000.18 April 2018 at 11:58 am #528315
@etmo I contacted Sigma to make sure I’m not doing something wrong with my stones. It turns out, they should not be stored in water for extended periods. The #1000 should soak 20 to 30 minutes before use, The #6000 and #10000 for 5 minutes. However, they said it is fine to toss the #1000 into the water and leave it there during the day while you are working so that it is ready to go when you need to sharpen, but then take it out of the water at the end of the work day.
These are the Sigma Power Ceramics, not the Select II that you have. One persons said that he puts the higher grit stones into water as he starts on the #1000 and by the time he is ready for the higher grits, they’re good to go. Other times, he just sprays them with water and doesn’t soak.
That all said, I’ve decided these stones are consumables and I’m not going to fuss too much, but don’t want to do something that will ruin them straight off.18 April 2018 at 9:01 pm #528842
Agreed that they’re consumables. Having said that, I’d like to get the best performance from them while consuming them, so I’m grateful for any info which helps along those lines.
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