Sharpening Suisin Special Inox 270mm Gyuto?

So i just bought a Suisin Special Inox 270mm Gyuto and the factory edge is pretty underwhelming. Not bad per se, but inferior to the edge i've put on my Victorinox Fibrox 10" chefs knife. It's holding well as i expected, but stupid me i started rubbing it on my grooved Wustof steel when it got noticeably dull after 2 days of heavy prep. Now after examining it under a jewelers loupe, i can see tiny chips on the blade. So i'm going to need to sharpen it sooner than i'd planned. Which is fine because i was looking forward to it anyways. The problem is, it's an asymmetrical edge and i've never sharpened one.

What i know(Think i know) is that a japanese knife doesn't just have an asymmetrical edge, the blade is actually ground asymmetrically, though i can't really tell by looking at it. So i can't just sharpen it symmetrically or it might start steering. I wanna sharpen it right so i'm here for help. It looks to be either 70/30, or 80/20. It's a pretty big difference, it's definitely more than 66/33. But this is just going by bevel length. The front(right) bevel looks to be slightly more than double the length of the back bevel. But i can't tell the angles. The front bevel LOOKS to be around 20o But i have NO idea about the back bevel, its just too small for me to tell. Are japanese knives typically just a deeper bevel and and equal angle on both sides? Or the other way around? Or both a deeper bevel and biased angle? I've looked and can't find a clear answer, and i am uncertain exactly HOW i should go about sharpening.

I'd really appreciate some help here.

First, I must admit I never sharpened or handled that knife. A few remarks though. In general about asymmetric sharpening

http://www.kitchenknifeforums.com/showthread.php/5656-Asymmetry-–-The-REAL-DEAL

Basically, you start somewhere behind the bevel with the blade very flat on the stone. Little by little you raise the spine until you've reached the very edge and raised a burr. Check your progress by looking at the scratch pattern or using the marker trick to see where steel has been abraded. Only when a burr got raised you flip sides and perform the same on the other side.
The advantage of this approach is that you may restore a previous configuration without having to worry about angles or proportions or counting strokes as EdgePRO victims tend to do. Starting behind the edge will make you thin a bit and compensate for the taper.
Please be aware a lot of factory edges are bit brittle. Anyway, once you attack a fine edge with a grooves steel the remaining edge has it's steel fatigued, and this steel has to got abraded. Don't hesitate to start with a relatively coarse stone, JIS400, and make sure to abroad some steel.
If you find it hard to replicate the factory edge -- which is plausible after steeling -- remember common values for a gyuto without any microbevelling are some 10 to 14 degree on the right side, and 15 to 22 on the other one.

Rmag37 said:

The front(right) bevel looks to be slightly more than double the length of the back bevel. But i can't tell the angles. The front bevel LOOKS to be around 20o But i have NO idea about the back bevel, its just too small for me to tell. Are japanese knives typically just a deeper bevel and and equal angle on both sides? Or the other way around? Or both a deeper bevel and biased angle?

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The short answer is, all of the above. Use marker on your bevels, pay attention to the original geometry, and thin as you go, and you'll be in good stead.

So from the sounds of things, i shouldn't worry about having defined shoulders on the knife? What you described is basically how i sharpen my vicroinox, and i can't even see the bevels under my loup, just a line of scuffs between the edge and face of the knife. I've ordered a idahone rod to restore the edge between sharpenings, so i wont be attacking it with the grooved steel again just because i already know thats not good for hard knives. Also, i only have a 1000/6000 combo stone, but i have a DMT red stone which iirc is about 600 or 400 grit. So basically i should start on the right side of the knife, immitate the angle, probably going a little lower, and after raising a good burr, working it, and deburring, swap sides and repeat as i work my way from coarse to medium to finishing stones? Also, i literally cannot tell the angle on the left side of the knife, its really small. I almost wonder if it is 90/10. Should the left side bevel be a higher or lower angle than the right? I would think a really small but low angle.

The reason a lot of makers have the left angle much higher is to compensate for steering and add stability without reducing performance too much. First stick with the existing configuration before changing it.

Rmag37 said:

So from the sounds of things, i shouldn't worry about having defined shoulders on the knife? What you described is basically how i sharpen my vicroinox, and i can't even see the bevels under my loup, just a line of scuffs between the edge and face of the knife. I've ordered a idahone rod to restore the edge between sharpenings, so i wont be attacking it with the grooved steel again just because i already know thats not good for hard knives. Also, i only have a 1000/6000 combo stone, but i have a DMT red stone which iirc is about 600 or 400 grit. So basically i should start on the right side of the knife, immitate the angle, probably going a little lower, and after raising a good burr, working it, and deburring, swap sides and repeat as i work my way from coarse to medium to finishing stones? Also, i literally cannot tell the angle on the left side of the knife, its really small. I almost wonder if it is 90/10. Should the left side bevel be a higher or lower angle than the right? I would think a really small but low angle.

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Re: shoulders: no, don't worry about it. The natural wobbling will ease them, and since the knife is thin it won't be very noticeable anyway. After a few sharpening sessions (5?) You'll want to learn more about thinning, which you can learn from the Japanese Knife Imports videos.

Re: stones: just use your 1000/6000 stone for regular sharpening, until you feel more confident. Keep your coarser stones for thinning later.

Re: the regular sharpening process: what you wrote seems about right, except for these:
- you don't need to deburr until your last stone (the 6000)
- the front of the knife (right side when you hold the handle) usually has a more acute angle than the back (rule of thumb: 2 pennies for the front, 3 for the back). But don't worry too much: just raise an even burr on one side, then the other, then go to the next stone or deburr if you're on the last stone.

Quite sure you can't remove all of the burr on the coarser stone, but don't let it accumulate until deburring on the finest one unless you're a very experienced sharpener.

Copy the factory bevels to start with. Avoid using a steel on those hard japanese knives, it's far too easy to fracture the edge without actually restoring the apex -- in fact, if you are not careful, you are doing the chipping by the way you use the knife.

Japanese hard steel knives will not tolerate chopping or rotation while "rocking" -- you will not roll the edge over like on a Wustof, you will break it off. I cringe every time I see a "chef" chopping something by whacking the knife edge through some food into the board with a steady "bang bang bang" of steel on wood. You can get by with this with a soft knife, but not a Japanese steel one. Bad technique, it's smashing the food anyway, at least after a couple whacks.

Use light pressure and be aware that it will take much longer to perform each step -- at least three or four times. I can zing up an edge on soft German steel in a couple minutes, and finish it out through stropping in about two more. Hardened steel aroung 61 or so Rockwell is going to take 15 or more just to get a decent bevel ground, and I have not yet succeded on one of my cheap santokus, even a trip to the bench grinder hasn't thinned it down enough yet to get a real edge on most of the knife.

Use light pressure, you don't want to develop more micro-fractures on the edge on a coarse stone.

Peter

dont even bother with the 6000 side, just strop on newspaper after 1000.

Is it possible to remove entirely the burr on a 1k stone? With modern stainless I don't get rid of them before 5-8k but that might just me.

I wasn't planning on completely deburring between bevels/stones but i figured it would make it easier to tell if i'm actually generating a burr, or just flipping it over from the other side. I just run it through one of the synthetic corks i grab from the bar when i switch sides or stones. I have wondered if a felt block would be a worthwhile investment, but i haven't noticed a problem with the fake corks.

Also, if i shouldn't be pivoting my knife with the edge of my blade on the board, or walking it across the board, what would be a good way to handle chopping fresh herbs in a reasonable amount of time? Maybe just stick with my victorinox for things that would torque the blade? The chef has me make up a large batch of "finely" chopped herbs once or twice a week, and i chop them the obvious way. I also chop parsley to fill a 1/6th pan for garnishing a couple times a week. Are there other techniques i should learn for these tasks?

On the topic of steeling my japanese knife, i had planned on lightly honing it on an idahone ceramic hone occasionally between sharpenings, i enjoy sharpening but i don't really want to do it multiple times a week, i think it would become a chore.

I bought an Old Hickory cleaver a while back and i was thinking maybe i'd practice thinning on that before i tried it on a knife i actually use. It's thick but it has horizontal grooves running across it which i worried might gauge my stone if i wasn't careful.

nm

There are lots of options for deburr, I take most the burr off on the stone any residual on newspaper. It is a good idea not to twist or tork a Japanese gyuto, but other than that you do not have to baby them or worry what kind of cuts you use.

Lightly honing with a ceramic rod will work. You can chop with a gyuto, but a small cleaver will smoke a french style knife for chopping duties.

keithsaltydog said:

There are lots of options for deburr, I take most the burr off on the stone any residual on newspaper. It is a good idea not to twist or tork a Japanese gyuto, but other than that you do not have to baby them or worry what kind of cuts you use.

Lightly honing with a ceramic rod will work. You can chop with a gyuto, but a small cleaver will smoke a french style knife for chopping duties.

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What do you mean by small cleaver? For chopping herbs i don't need much weight behind it or force, i have always felt that a sharp edge and length of the blade were the most helpful attributes a knife could have for chopping or mincing herbs/shallots/onions/garlic.

For "chopping" things like celery/zuchini/cucumbers i typically just use the tip to chop them rapidly, or tip down guillatine if i can get away with cutting rows at a time. I've thought about getting a Nakiri or Usuba for veg chopping duty though.

I used cleavers a lot putting out banquets. An Usuba is a specialized tool, to me a Nakiri is too small for quantity prep. I will give you an example of a nice small cleaver (Chinese Chefs Mall) under small cleaver CCK KF 1915 high carbon triple steel, 19.5x7x2mm.

With chopping you can use two hands, one on handle & other pinching spine near the tip. Using the entire blade as a chopper. Gathering the food edges to the center you can really cut quickly, much faster than a gyuto.

I've found a better way to find bevels and factory edge is to tightly wrap the stone in a thick layer of newsprint...take the entire sports page of your losing team and tightly wrap it arounds the stone. Make sure it is tight and taught, not lose and rolled too much. A little is fine Next strop the blade as flat as possible. Move slowly higher until the paper tears, there you have found the angle to work the edge.

So i spent 2 hours today trying to sharpen the suisin on a 1000 grit stone. Nothing. No burr, no swarf, no visible change to the edge besides scuffing only visible under my loupe. I thought maybe i had clogged the stone flattening it on 150 grit wetordry sandpaper, so i tried taking some material off using my usual flattening method, red DMT stone. Swarf achieved, back to the stone, nothing with the suisin. Maybe cleaning will help, nope. Maybe its the knife. So i grab my victorinox and am able to sharpen it just fine as usual. Nice brown mud forming as i go. Looks like its the knife. So yeah. Apparently my suisin wont abrade the stone enough to make mud? This makes no sense to me. I expected it to sharpen slowly being harder, but it won't sharpen at all. Anybody know whats going on?

If its relevant, the stone is a 1000/6000 grit combo stone SteeleX brand sold by Woodstock International.

@keithsaltydog I looked at the CCK small cleaver on **************, its on my wishlist and i'll probably grab it at some point. Between that and the CCK Large Slicer also on **************. Any input on that choice? For a veg chopping and i guess herb chopping knife.

You're not hitting the edge, raise your angle. The suisin is going to be a lot more acute than your victorinox.

The sharpie trick made it look like i was hitting the edge, i ended up deciding the right edge was almost 25o. Are you sure i'm not hitting the edge? Was i just getting very close? Definitely not as acute as my victorinox, i have it under 20o on each side. I just need to steel it very frequently. Maybe the asymmetry of the suisin makes the seemingly high angle relatively low.

When you figure it out that Suisin will be easy to sharpen. You have probably thinned behind the edge a bit with 2 hours on the stone. Are you using Jons technique with handle hand controlling spine height & fluid movement of knife as each section is sharpened. The blade hand the fingerpads near the edge always over the stone. This hand controls pressure & moving the blade up & down the stone. This is a very efficient tech for raising burrs because the blade edge is between the fingerpads & the stone. I use three fingers along edge two at the tip.

When you raise the spine to put on your final bevel you can hear the bevel being cut in. One progression on each side is all you need to create a even burr heel to tip. Then all you have to do is the light touch of burr removal so you don't round your edge.

The cleaver I reccom. is not on CKTG it is (Chinese chef mall) The popular 1303 carbon has got overpriced. The KF 1915 is an excellent small vegetable cleaver. High Carbon stain resistant steel. Gets razor sharp.

A while back I watched the original Karate Kid movie had not seen it in years. The part near the tournament date Daniel Sans birthday where Mr. Miage gives him the Jacket for the tournament with the Patch his departed wife had made. He is concerned that he has not learned enough to survive the full contact competition. Miage tells him it is not the Quantity it is the Quality. So true in Martial Arts as well as in freehand sharpening. Focus on good technique, over sharpening can be counter productive. If you already have success sharpening your Victorinox you will get there.

I recently switched over to Jons technique after immitating Vincent from... a video series i can't recall atm. I struggle with my edge leading strokes though, my fingers don't grip it so its hard to pull with my edge hand. I'm about to head back to the stone for another try. Ill try raising the angle even more it's already shockingly high though. But i guess factory bevels are factory bevels. Probably not to ambitious.

How about consulting Jon Broida about this via mail. He sells these knives and definitely know them very well. He is also a very nice guy who is always willing to help.
- Kim

KimBronnum said:

How about consulting Jon Broida about this via mail. He sells these knives and definitely know them very well. He is also a very nice guy who is always willing to help.
- Kim

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I didn't buy the knife from him or i probably would have. Anyways, i raised my angle some more and was able to fix my edge. I work tomorrow so i can test it out to see how i did, but i get the feeling i'm going to want to change the factory bevels pretty quick. Right side was probably 5 quarters high, and left side was probably 6. I was pretty shocked. I also think i found a new way to feel burrs, i put a wet hand towel between my finger and the side i was checking for burrs and slowly pulled it, and i could feel the burred side catching on the fabric. Previously i had been scratching at the edge of the knife with my finger nail and i had trouble feeling a burr on the suisin this way. I am a little worried though, i couldn't get the burr off just running it through synthetic cork, i guess because of how hard the knife is. So i stropped on the 6000 grit stone a couple times and i was able to weaken it enough to get it off, but now i'm worried i rounded the edge. The victorinox was very easy to deburr, just 2 or 3 passes through the cork and it came right off.

Not so sure whether these bevels are a part of the factory edge or made with your grooved steel. Anyway, relatively obtuse angles aren't that uncommon with very thin blades. See them as some micro- or minibevels.

Benuser said:

Not so sure whether these bevels are a part of the factory edge or made with your grooved steel. Anyway, relatively obtuse angles aren't that uncommon with very thin blades. See them as some micro- or minibevels.

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It's really not all that thin honestly. I'm not entirely sure if its stamped or not, but if it is a stamped blade, it's pretty average thickness. It did come thinned around 1/3 an inch behind the edge, so maybe thats why the bevels themselves are so shallow. I don't think they'd be related to the grooved steel, I only did maybe 20 or 30 strokes each side all day long before i realized i shouldn't be using it. And the bevels were pretty smooth. Just out of curiousity, how do people thin evenly? I would think thinning poorly would result in a very steery blade. I've never thinned before and wont make this my first thinning project, i was just curious because i'm probably going to want to thin within 6 months.

20 to 30 strokes per side on grooved steel NOT causing any microbevelling?? A few strokes would do, and make any use of the marker trick to restore the factory edge uncertain. Now the original edge must be considered as lost, let's find a solution. I would sharpen both sides, beginning by the right one, at the lowest possible angle, until you raise a burr. So at least you're sure the fatigued steel from the steeling got abraded. From this point on, you may create a 10 degree right side, 15 degree left edge. Just a few strokes will do. See how this edge holds in daily life.

Benuser said:

20 to 30 strokes per side on grooved steel NOT causing any microbevelling?? A few strokes would do, and make any use of the marker trick to restore the factory edge uncertain. Now the original edge must be considered as lost, let's find a solution. I would sharpen both sides, beginning by the right one, at the lowest possible angle, until you raise a burr. So at least you're sure the fatigued steel from the steeling got abraded. From this point on, you may create a 10 degree right side, 15 degree left edge. Just a few strokes will do. See how this edge holds in daily life.

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How would a soft grooved steel remove enough metal to change the bevels? It would pull off pieces of fatigued steel obviously, but the bevels didn't appear to change in size or anything. If there was a micro bevel i had to get past thats probably why i had trouble sharpening it initially, but wouldn't i have flattened the bevel sharpening it? I probably wont have a chance to sharpen before i work next so i guess i'll see how the knife does and try to sharpen after work. Wish there was some way i could find out what the factory bevels WERE. Google has been no help. Took some searching just to find out it was Aus10 steel.

Also, I think raising a new burr from the shoulders would take way more than a few strokes, i sat for hours the other night falling short of the edge and accomplished nothing. I would need a courser stone for that, i do have a dmtred which is 600"mesh" and i've used that to put new bevels on other knives.

A grooved steel is not soft at all and may destroy your hard edge within seconds.

First off, get rid of the steel. Ceramic sharpening rod or nothing. I have a couple of Suisin western handled knives, one is a single bevel and the other a double bevel. If not mistaken, are not the double beveled knives set at a 90/10? I have to say these might be the two easiest knives I own, to sharpen.

The "Vincent" you originally watched is almost certainly the same Vincent from Korin - one of the sponsoring vendors here. The also sell the Suisin Special Inox. Suggest you post a pm to "Mari", Korin's representative here or email Korin with your questions for a definitive answer. And chuck the steel.