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Masamoto VG Gyutou 240mm - Sharpening Help

post #1 of 33
Thread Starter 

I received a new VG10 Gyutou a few weeks ago and it has been amazing.  I also picked up the Idahone Ceramic "Steel,"  and I am beginning to educate myself on "proper" knife sharpening, i.e. stone sharpening either by hand or EdgePro.  I do believe that I could learn free-hand however being an engineer I strive for that perfect edge.  Therefore I am planning to purchase the Chosera EP system from CKTG.

 

Now my dilemma, the VG 10 has an asymmetrical bevel 70/30 right handed.  I can see visually that the bevels are not a consistent 70 or 30 along the edge of the blade.  I am very leery of "re-profiling" the edge myself to get the consistent edge i desire.

 

Should I send the knife out to a professional such as Carter Cutlery or similar for the initial edge profiling?  I have heard that Mr Dale from EdgePro will do this as well. 

 

I would be confident in maintaining an edge using the EP if the edge was created by a "professional" first...

 

Thanks for you help!

Chris

post #2 of 33

The knife is a Masamoto VG, not VG-10.  If they were ever VG-10 they became something else several years ago.  Korin is the only retailer I know of that calls the knives VG-10 -- who knows why.  Cook's Illustrated still lists them as VG-10, presumably because they don't know any better which should tell you plenty about CI's knife review competence. 

 

The VG is a truly wonderful knife, even if CI it and gave it a "best" endorsement.  Congratulations on getting one. 

 

The EP is a good system for newbies whether or not they're engineers.  It has its limitations, but you probably won't bump against any of them. 

 

You don't need a full on Chosera set, but since I don't follow EP pricing all that closely I'm not prepared to call it a waste of money either.  Choseras are definitely good stones, they have some drawbacks besides being overpriced but they won't likely effect you.  Similarly, their greatest advantage is speed and that doesn't count for much on an EP either.

 

The VG will take and hold a polish at the polish at the 10K level, but I'm not sure that the Chosera does any better job than either Ben's sharpening tapes or the comparable Shaptons.  The best solution may be tapes leading to one or two stones.  If you have questions try calling Ben (Mr. Dale). 

 

Once you've got the EP reasonably well figured out -- a process that will require you to sharpen four or five knives -- "opening" the VG won't be much of a problem.  But, it's never a bad idea to have a knife sharpened by someone who really knows her (or his) stuff.  My first choice in sharpeners for a chef's/gyuto is Dave Martell at Japanese Knife Sharpening.  Carter's sharpening services are equally fantastic.  Ken Schwartz is just as good with those types of knives -- you can contact him through Chefs Knives To Go (and tell him "hi" from BDL, and same for Dave). 

 

70/30 is not magic symmetry for the VG, (again) despite what Korin says.  It appears Masamoto sharpens its western handled knives by sliding them across a grinder until they develop a burr on one side, then turning them over and sliding them across the other bevel until the burr flips back. The result is roughly twice as much bevel on one side as the other, and an edge that's good enough to fool around with until you can get the knife properly sharpened.  I call it a Christmas Morning Edge.

 

It's my understanding that Masamoto anticipates most users will end up with something very near 50/50.  But what they think doesn't matter much.  It's your knife. Sharpen the knives to whatever degree of asymmetry you like.  The ratio of the right side bevel to the left will tell you the symmetry.  Dude, it's just trig. 

 

I forget just how adjustable the EP is (or isn't).  You can sharpen each bevel to something more acute than 15* without many problem.  Anything steeper than 10* is probably pushing it.  Sharpen both sides at the same angle.

 

The more asymmetry the sharper the knife will act, the less likely it will be to wedge, the less durable it will be, the more it will tend to "steer" when used by someone who's wrong-handed.  If you sharpen the knife more assymetrically than 2:1, you limit your ability to use a steel for maintenance because of the way the pressure from the rod will cause the shearing force to bend the edge where it's weakest, causing it to fatigue too quickly.

 

Hope this helps,

 

Enjoy,

BDL

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post #3 of 33
Thread Starter 

BDL - Thank you for the reply and I'm sorry for the misnomer of the VG-10 reference, I was getting that from Korin.

 

In regards to your comments about sharpening; you mention that the EdgePro with Chosera stones may be overkill?  Is that accurate?  Chef Knives to Go has an EdgePro Apex with a set of modified Chosera Stones for $275.  After lurking here for a few weeks and reading many posts I found that offering and thought it would be a good first setup.  I debated getting stones and learning freehand but like the guide of the edgepro for reassurance of proper angle. 

 

You also mentioned some drawbacks of the Chosera stones would you mind elaborating a bit?

 

I have sharpened knives free hand before but only hunting and pocket knives on oil/water stones.  This was back in my eagle scout days, and nothing near a mirror polish on a kitchen knife.

 

Basically what I desire is to learn the skill and keep the VG and our other kitchen knives properly sharpened and usable rather than having someone else do it for me.

 

Thanks!

 

Chris

post #4 of 33
Thread Starter 

nm


Edited by cscharti - 8/5/10 at 8:52pm
post #5 of 33

 

Don't worry about the VG - VG-10 thing.  Like I said, it comes from Korin.  They've got a few pieces of misinformation they absolutely won't let go of, an excellent sharpener with a few strange opinions of his own, but are in every way an estimable outfit.

 

One of their peccadilloes is to recommend against using a steel for any Japanese knife.  Unless you're sharpening the VG to a high degree of asymmetry, you want to use a rod hone (aka steel).

 

How asymmetric should you sharpen it?  If the knife will be used by only one person, or everyone's same-handed, and you value a slight increase in absolute sharpness over durability, sharpen to no more than 2:1 asymmetry.

 

If the two of you are other-handed, unless one of you has strong skills, sharpen to 50/50.  Most stores that ship Masamoto wa-gyutos (different handle, same blade shape) sharpened, have them sharpened to 50/50.

 

My wife is right-handed, I'm left-handed, my technical knife skills are much better than hers, and I sharpen our knives to 60/40 righty.  

 

In the post you deleted, you asked about determining angles.  I assume you deleted it because trig enlightenment burst over you like a thunderstorm.  If not, ask.   

 

As to the Choseras, pretty much I wish I hadn't brought it up. 

 

OK, OK.  I'm whining about money.  When it gets down to it, you aren't saving much if you add a 10K to one of the other kits, and spending more if you add both a 5K and 10K.  Since the VG can take and hold a 10K polish, wotthehell wotthehell. 

 

With knives and sharpening, there is no best for everyone and probably not even a best for you.  Learning to freehand is not that big a deal. But it is a deal, and I understand and respect your desire not to deal with it.  The EP/Chosera set up will do a great job on your knives once you've got it figured it out -- which won't take long.

 

BDL

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post #6 of 33
Thread Starter 

BDL - Thank you greatly for your help, it is much appreciated.  The reason for deleting the other post was that I realized that I did not intend to ask specific angles just to get a sense for what type of edge to pursue, and you answered that beautifully.  The math is relatively easy once you pick an edge configuration.

 

As for our household my wife and I are both right-handed but she prefers a Santoku anyway so most likely I will be the only one using this knife.  I think the best bet my be a 60/40 or 70/30 right-handed sharpening.  Which leads to another question...

 

The center line of the edge of the knife...One cannot just use one angle to produce a non symmetric edge lest the edge be off center of the knife.  If my math serves me correct a 70/30 would result in a 9 degree angle on the left of the knife and a 21 degree angle on the right side to maintain the edge in the center of the knife.  Similarly 60/40 is 12 degrees left, 18 right.  Using an EP in this case would require setting and resetting the device multiple times during an asymmetrical sharpening.  Is that correct?  Maybe I should contact Mr Dale to ask...This is where I question whether I should free-hand or not...and now I confuse myself again.

post #7 of 33

 

CS,

 

I am sooooooo glad you brought this up.

 

Right handed asymmetry means that the knife's left side bevel (holding the knife by the handle) is sharpened wider than the knife's right side bevel.  Unsurprisingly, left handed asymmetry results from the reverse.

 

As a practical matter, asymmetry usually means the apex of the bevels (i.e., the edge) is NOT on the center line.  Almost all knives sharpened on both sides are profiled with the same edge angle on each side, and even more of them should be. 

 

In engineer speak:  The choice of edge angle and symmetry is all about balancing stress and fatigue against wedging within the context of (material) strengh and toughness.  You want the part of the knife just above the actual edge to be as thin as possible while robust enough to stay "in true" and not tear or chip.

 

Greater symmetry translates to greater width (and stress resistance) just above the edge.  If you're going to steel (and you should) as part of maintenance, you need a enough symmetry to prevent a stess line from beginning at the bevel shoulder on the short side, running through the center of the knife to at an oblique angle.  If the knife is too thin at the short side shoulder bevel, the alloy will fatigue enough to make it more likely to bend -- or even tear.  If this is unclear, we can go into more detail in a subsequent post.

 

66.6/33.3 (aka 2:1) is a sort of max asymmetry if a rod hone will be in the picture.  Eyeballing bevel proportions isn't that exact, so shoot for 60/40.  Your knife will still be unbelievably sharp compared to whatever you used before. 

 

If you're not going to steel, but "retouch" on your EP everytime the knife gets slightly out of true, you should sharpen to the greatest degree of asymmetry the knife can hold.  I'm not sure how far you can push the VG.  80/20 anyway.  I have a friend who sharpened his to a near chisel (call it 90/10) for restaurant use.  It was very sharp, but kind of marginal about making it all the through a service.  He'd recommend it, but I don't.

 

You'll want to use The Magic Marker Trick when you first start grinding in asymmetry, so you can actually see the bevel shoulders and compare them to one another.  If nothing else, this should reinforce the ideas that you're eyeballing symmetry by rough proportion, as well as the importance of keeping a smooth shoulder parallel to the intended edge.   

 

By the way, the "included angle" is determined by adding the values of the edge angles.  A 15* edge angle on each side means an 30* included angle. 

 

The "default" edge angle for most sharpeners doing Japanese knives is 15*.  Better is to sharpen the most acute angles the knife will hold without the edge collapsing too frequently.  In the case of the VG, that's probably just a skosh more than 10*.  It's something you can play around with for awhile.  If you don't want to fool with it, split the difference and set the EP as close as you can get to halving the difference between the 10* and 15* marks as you can.

 

After four decades, I'm still messing with my Sabatiers.

 

Bottom Line:

~60/40 righty at ~12.5* (both sides) is a good default.  Alternatively, try 10*, also at 60/40.  If that doesn't hold up long enough for you, sharpen a 15* "primary bevel" on top.  You might really like the way a double bevel combines thinness with durability.

 

BDL

 

PS.  Since the question is probably going begging:  I am not a trained engineer.  But have some small background in physics, more of one in math, and picked up a little materials science on the street corner over the years. 

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post #8 of 33
Thread Starter 

Ok we're getting there.  I do have a ceramic hone and plan to at least use it to keep the edge sharp until sharpening is needed.

 

So it sounds like a 60/40 is probably the best bet at say 12.5 degrees to start.  Please correct me if I am wrong but since the same angle is used on both sides the to get a 60/40 edge the actual amount of sharpening (material removed) would be 60% on the left side and 40% on the right for right handed.  So for example with an EP one would set the angle and sharpen 60% on the left and 40% on the right (i.e. for every 10 strokes on the right you would make 15 strokes on the left for the very first "opening" sharpen)  Is that accurate, or have I missed something...

 

Thanks greatly.

Chris


Edited by cscharti - 8/6/10 at 3:46pm
post #9 of 33
Thread Starter 

BTW I looked at my VG tonight and it looks like the longer/wider bevel is on the right side of the knife if I am holding the knife by the handle and looking down the knife, cutting edge down.  I assume this is correct...I have yet to sharpen the knife after purchase.

 

Chris

post #10 of 33

 

Yes.  The wider bevel should be on the right side. 

 

Yes.  60/40 refers to the ratio of the bevel widths   If, for instance, the right side bevel was 9 mm wide, the left side bevel would be 6mm.  It is not important to measure the bevel widths to any great accuracy, the Mk IV GI Eyeball will do well enough. 

 

It depends.  Bevel width would be proportional to the amount of material removed if you were starting with an unsharpened knife.  Otherwise not so much.

 

No.  You may not confidently assume that the number of strokes will be  proportional to the desired bevel width or amount of material removed.  There are too many variables.  You must measure the bevels -- either by eye (which should be good enough) or find some other, more accurate method.

 

You can make the bevels more visible by using the magic marker trick.  Ben has at least one video up on his site or You Tube (I forget which) showing you how.  It's not difficult, you simply paint a 3/4" wide line along the edge with a Magic Marker.  When you sharpen the knife, the Marker ink will abrade off along with the steel. 

 

The upper demarcation between marker and abraded blade is the bevel shoulder. 

 

On the lower, edge side of the marker, if you haven't abraded all the marker from the edge, you did not sharpen the edge. 

 

The bevel shoulder should be an even line, running parallel to the edge from the heel (almost) all the way to the tip.  If the bevel shoulder is uneven, you have high and/or low spots.  The presence of either means the bevel is not flat.  If the bevel is not flat, the knife will tend to bend and break at the weakest points, will not steel correctly, and be difficult to resharpen.  So, you have to grind the high spots down.  You always want a flat bevel before leaving any grit level for a higher one.

 

Note:  Because of the arc of the tip and the geometry of the EP that arc will most likely be sharpened at a slightly more acute angle than the rest of the blade and consequently have a slightly wider bevel.

 

To establish your 60/40, right handed, 12.5* edge on an EP: 

Mark the left side of the blade with Magic Marker.  Prep your coarse stone and use it to profile a 12.5 degree bevel just until the Marker is removed from the entire length of the edge. 

 

"Section" the knife (selectively sharpen narrow areas) as necessary to remove any high spots.

 

Flip the knife over, mark the right side as you did the left.  Sharpen the right side as before.  When the Marker is removed from the edge, take the knife off the EP's table and estimate the proportional widths of the right and left side bevels.  Return the knife to the table and continue sharpening the right side until the desired proportion is achieved.  

 

Once your bevels are set, you can continue to sharpen the knife using higher grits in sequence.  It is not important which side you sharpen first, only that you maintain their proportional relationship. 

 

Continue using The Magic Marker Trick with all your stones for your first few couple of sharpening sessions.  After a short while you'll learn to see and feel the edge bevels without it. 

 

BDL


Edited by boar_d_laze - 8/6/10 at 7:39pm
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post #11 of 33
Thread Starter 

BDL - Thanks greatly for your time and advise it is greatly appreciated.  You are an asset to the forum and I hope to learn a fraction of your vast knowledge. 

 

Chris

post #12 of 33

OK BDL, I think I'm misreading or misunderstanding something (that just might be because I'm a "lefty" )

 

For a "righty", looking at the spline, is the larger bevel, say 60, on the right or the left?

 

What is confusing to me: I presume that a single bevel (chisel edge) knife for a "righty" has the bevel on the left, correct? The right side is FLAT, correct?

 

Would that be a 0/100 or a 100/0?

 

My intuition (which is rarely right ) says that the narrower bevel should be on the same side as the "hand" of the user, correct?

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post #13 of 33

Hi Pete,

 

OK BDL, I think I'm misreading or misunderstanding something (that just might be because I'm a "lefty" )

 

We southpaws are different in more than just handedness. 

 

For a "righty", looking at the spline, is the larger bevel, say 60, on the right or the left?

 

On the right.

 

What is confusing to me: I presume that a single bevel (chisel edge) knife for a "righty" has the bevel on the left, correct? The right side is FLAT, correct?

 

No.  You've got it bass ackward.  Imagine that you were using the "claw" technique with your offhand.  You'd want the flat part of the knife against your knuckles, because the bevel would force the knife to twist. 

 

Would that be a 0/100 or a 100/0?

 

Anaylytically it doesn't matter.  As a matter of language, you always put the biggest number first.  For instance, you'd say "60/40 right" or "60/40 left" rather than reversing the numbers to show a different handedness.

 

I don't use 100/0 as a term, I just call it chisel or hamaguri (depending on whether the back of the knife is flat or concave.  Other people use the term however they want.  In real life, chisel edges aren't truly 100/0 because you have to take enough of a bevel off the back to deburr.  The "clamshell's lip" on a hamaguri is the only truly 0 back bevel I know of.   

 

My intuition (which is rarely right ) says that the narrower bevel should be on the same side as the "hand" of the user, correct?

 

Not correct; already described with the "claw" example.

 

The reason you sharpen asymmetry depending on the hand is wrong-handed asymmetry tends to steer, while correct-handed asymmetry tends to stay square with the board.  The better the user's grip and the higher her (or his) skill level, the less the tendency. 

 

I -- a lefty with good grip and good skills -- start to fight the knife at around 70/30 right.  My wife is a righty so I sharpen our knives to around 60/40 right which allows us a slightly thinner bevel, helps her a little, but doesn't make it awkward for me.

 

If you or I were using a right-handed chisel or hamaguri edged knife, with a thick body above the blade road, sharpened to a very acute angle, and with a consequently very wide bevel, the angled bevel really would push the knife off making thin cuts difficult, and also cause the edge to rotate away from the claw.  The example was more than hypothetical. 

 

BDL

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post #14 of 33
Thread Starter 

BDL,

 

I wanted to thank you for your help in the topic above.  I set up my EP this weekend and began my learning experience on an old Henckel's International lest I screw something up I wouldn't care.  It was slow going at first and I didn't know much of how to begin so I jumped right in.  Once finished with the first knife I wasn't too impressed with my skills but I insisted that I continue.  I moved on to a ceramic pairing knife not yet sure if I could tackle our mid-range Henckel Twin Cuisine knives.  The second knife was a bit better I just matched the factory edge.

 

Now the fun begins, I decide to go for it all.  I set the EP to 15 degrees and decide that I want to open my first knife the twin cuisine pearing knife.  Eek, it seemed like forever before I could rid the edge of the black magic marker and OH does the tip look bad.  I still manage to get a better edge than the knife had ever seen even with the poor tip.  The EP does have a few nuisances and sharpening the tip properly is one of them!

 

Now I have a bit more confidence I grab the small twin cuisine chef's knife and begin the process again.  This time it goes very smooth and it’s almost starting to feel natural.  Once the small chef's knife is complete to the 5000 Chosera stones, I finish out our block; the large chef, slicer and wife's santoku.

 

Now the real fun, I'm starting to feel extremely comfortable and I begin with the VG.  I lower the angle to 12.5 and drop to the 400 grit Chosera. (I used 1000 grit stones prior only using the 400 once)  I mark the edge with the sharpie and take a stroke, wow do I have long way to go...

About 10 minutes later I have a great looking 2:1 righty edge staring at me.  I proceed through the set of stones finishing with the 10k resulting in a mostly mirror finish, and wow is this baby sharp!!!  I may be bitten and I love how consistent I could keep the edge thickness across the knife.

 

 

VG.jpg

post #15 of 33
Thread Starter 

BDL,

 

I wanted to thank you for your help in the topic above.  I set up my EP this weekend and began my learning experience on an old Henckel's International lest I screw something up I wouldn't care.  It was slow going at first and I didn't know much of how to begin so I jumped right in.  Once finished with the first knife I wasn't too impressed with my skills but I insisted that I continue.  I moved on to a ceramic pairing knife not yet sure if I could tackle our mid-range Henckel Twin Cuisine knives.  The second knife was a bit better I just matched the factory edge.

 

Now the fun begins, I decide to go for it all.  I set the EP to 15 degrees and decide that I want to open my first knife the twin cuisine pearing knife.  Eek, it seemed like forever before I could rid the edge of the black magic marker and OH does the tip look bad.  I still manage to get a better edge than the knife had ever seen even with the poor tip.  The EP does have a few nuisances and sharpening the tip properly is one of them!

 

Now I have a bit more confidence I grab the small twin cuisine chef's knife and begin the process again.  This time it goes very smooth and it’s almost starting to feel natural.  Once the small chef's knife is complete to the 5000 Chosera stones, I finish out our block; the large chef, slicer and wife's santoku.

 

Now the real fun, I'm starting to feel extremely comfortable and I begin with the VG.  I lower the angle to 12.5 and drop to the 400 grit Chosera. (I used 1000 grit stones prior only using the 400 once)  I mark the edge with the sharpie and take a stroke, wow do I have long way to go...

About 10 minutes later I have a great looking 2:1 righty edge staring at me.  I proceed through the set of stones finishing with the 10k resulting in a mostly mirror finish, and wow is this baby sharp!!!  I may be bitten and I love how consistent I could keep the edge thickness across the knife.

 

VG.jpg

post #16 of 33
Thread Starter 

BDL,

 

I wanted to thank you for your help in the topic above.  I set up my EP this weekend and began my learning experience on an old Henckel's International lest I screw something up I wouldn't care.  It was slow going at first and I didn't know much of how to begin so I jumped right in.  Once finished with the first knife I wasn't too impressed with my skills but I insisted that I continue.  I moved on to a ceramic pairing knife not yet sure if I could tackle our mid-range Henckel Twin Cuisine knives.  The second knife was a bit better I just matched the factory edge.

 

Now the fun begins, I decide to go for it all.  I set the EP to 15 degrees and decide that I want to open my first knife the twin cuisine pearing knife.  Eek, it seemed like forever before I could rid the edge of the black magic marker and OH does the tip look bad.  I still manage to get a better edge than the knife had ever seen even with the poor tip.  The EP does have a few nuisances and sharpening the tip properly is one of them!

 

Now I have a bit more confidence I grab the small twin cuisine chef's knife and begin the process again.  This time it goes very smooth and it’s almost starting to feel natural.  Once the small chef's knife is complete to the 5000 Chosera stones, I finish out our block; the large chef, slicer and wife's santoku.

 

Now the real fun, I'm starting to feel extremely comfortable and I begin with the VG.  I lower the angle to 12.5 and drop to the 400 grit Chosera. (I used 1000 grit stones prior only using the 400 once)  I mark the edge with the sharpie and take a stroke, wow do I have long way to go...

About 10 minutes later I have a great looking 2:1 righty edge staring at me.  I proceed through the set of stones finishing with the 10k resulting in a mostly mirror finish, and wow is this baby sharp!!!  I may be bitten and I love how consistent I could keep the edge thickness across the knife.

 

 

VG.jpg

post #17 of 33
Thread Starter 

Sorry for the triple post, the system told me there was an error but they posted...

 

Chris

post #18 of 33

This is a bit of an old post and I hope people don't mind me reviving it.  I too have a Masamoto VG gyuto (240mm) and have an edge pro on the way.  I am confused by what's in play when we're talking about dealing with assymetric bevels.  Korin's sharpening guide says that when freehanding, the right side of the knife should be lifted to  two-coins' height and the left at three coins' height.  It also says that the right side should get roughly 7/3 the amounting of sharpening that the left side is getting.  As I understand the advice in this thread, when sharpening a Masamoto gyuto on an EP, one should use the same angles on both sides (12.5 degrees was suggested) and shouldn't grind the right side any more than the left.  If neither of these are being done, how does one preserve the asymmetric pre-set (presumably 70/30 bevels) on an edge pro?  And how is that squared with Korin's advice?

post #19 of 33

This is an old thread put thought I would post this for anybody looking for the same answers I was when I found it:

 

 

I recently purchased a left handed Masamoto Wa Gyuto 240mm. (actually runs long a bit so glad I did not go for the 270 as my knife skills are not great)

 

Quote:
You are left hander, so Masamoto craftsman made proper edge shape for left handers too. (Opposite side of blade edge is bit sharpened more than face side of blade edge. Face side of blade has Masamoto Engraving Logo).
 
For sharpening your Masamoto KS Wa Gyuto, please follow below directions.
 
For sharpening opposite side of blade edge (Opposite side of blade does not have Masamoto Engraving Logo), we recomend the sharpening angle approximate 12'. For sharpening face side of blade edge (Face side of blade has Masamoto engraving logo), we recomend the sharpening angle approximate 15'. You sharpen opposite side of blade edge more than face side of blade edge. (for keeping its original edge shape). If the total times of sharpening strokes are considered as 100%, you sharpen opposite side of blade edge for 70%, you sharpen face side of blade edge for 30%.
 
We hope above information will help your sharpening process and keeping the left hander's edge shape.
 
Thank you very much again for shopping with us and your continued support.
 
Have a great cutting and great cooking time !!
 
Best Regards
 
Koki Iwahara

 

 

I had to read this a number times to get the sharpening instructions in my head for a left handed asymmetric blade. 

 

Definitions

Holding the knife in my left hand as if I was going to cut with it, tip facing north:

  • Inside face - the right hand side of the knife which faces the user, which is the side that has the logo on it. Eastern face
  • Outside face - the left hand side of the knife which faces away from the user, which is the clean side no logo on it. Western face.

 

 

Asymmetric Bevel

If you think of single bevel knife the inside face is flat (possible concave or small micro bevel on it), the outside face a big bevel. It it were a chisel the flat side is on the inside face, the chisel point would be on the outside face. The same goes for the bevel on the knife, the bigger larger bevel goes on the outside face, the smaller "micro" back bevel goes on the inside face to keep it as close to flat as possible.

 

Outside Face

-Angle 12 degrees

-Bevel Size 70/30 approximately 66/33 that is 2 x the size of the inside face or as a ratio of bevel size of outside to inside face of 2:1

 

Inside Face

-Angle 15 degrees

-Bevel Size 30/70 approximately 33/66 that is ½ the size of the outside face or as a ratio inside to outside face of 1:2

 

Procedure

 

I used the Wicked Edge Pro System (WEPS)

 

I set the outside face angle up using an angle cube and obtained the more acute 12 degree angle from my WEPS by flipping the locking detent screw around to the plain side and tightened up the detent screw with little pliers (which I do normally because they always come loose during sharpening).

 

I setup the inside face by selecting the 16 degree mark on the WEPS which when measured on an angle cube gave me 15 degrees on the belly and 13-14 degree angle on the tip. Just a word of warning whilst the WEPS has angles marked they are only a guide because the true angle will change depending on blade height and position, it is basic trig really.

 

Progression

-1000 grit (2000 JIS, 6.7u) diamond stone to set the bevel

-1200 ceramic (5u)

-1600 ceramic (5000 JIS 2.85u)

-Stropped with 0.5 micron CBN paste (I would have used 3.5u paste first but I have nicked the strop badly so skipped it)

 

I don't have my Naniwa-Chosera 5000 and 10000K Water Stones yet but they are in the mail. 

 

Bevel Setting

Used a magic marker to eye ball it

-set the outside face first until a good burr and consistent looking bevel for the entire edge

-set the inside face second until a good burr was reached, this resulted in a very small looking micro bevel on the blade.

 

I then went back and forward until by eye sight it looked like I had a ratio of 2:1 outside to inside face, in reality it is probably closer to 70:30 it is very hard to guestimate even using a belomo 10x loupe

 

I then run though the progression very little pressure was applied gentle strokes some scrubbing of the tip because of the more acute bevel of the angle, once the bevel was set moved though progression.

 

Final Result

Will lop hairs on my arm in half without touching my skin, tried dropping a tomato on the blade chopped it clean in half, can slice tomato super thin. Not worked with it for long yet so not sure how durable my edge will be.

 

post #20 of 33

Personally, I wouldn't bother with different edge angles.  If 15* is acute enough for one side, it's acute enough for another.  My experience with western style Masamoto knives is that they're indifferently sharpened at the factory, and they don't actually bother with different angles either.  Koki's been drinking the Kool-Aid.

 

70/30 or 66.67/33.33 are functionally the same.  Don't make yourself trying to figure out which is better.   On the one hand, it's about the cheapest and fastest way possible to sharpen a knife.  On the other hand, it's enough asymmetry to give you a performance bonus, while still sufficiently symmetric to maintenance with a steel.  A fair balance in the tension between absolute sharpness and durability.

 

There's no need to buy a "left handed" knife.  If you can sharpen, it's easy enough to push the bevel over -- especially over time. 

 

All trig is basic. 

 

BDL

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post #21 of 33

DSC_5563.jpg

post #22 of 33

Hi BDL

The handle is asymmetric hence why I brought the lefty model (tear dropped or D shaped, but I sell prefer it over my lefty shuns which are similar shaped, better looking but not better feeling). I took a picture but as a newbie it is awaiting moderators review. I left the tomato slices on post the pic and forgot about it and they were really black post 1hr sitting on the blade. I tried so bi carb soda to clean it up which worked well, and some 14u diamond paste to rub out the rust marks, still has a couple marks but has settled. 

 

Now I feel silly for not wiping the blade down.

post #23 of 33

My bad.  Even though you were very specific in your post, I didn't realize you were talking about a wa handle, much less a D shape.  Careless reading on my part. 

 

Otherwise, though...

 

BDL 

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post #24 of 33

Just looking at your thoughtful posting much later but since I recently purchased my own Masamoto 210mm Gyuto and sharpening on WE Pro thought I might share experiences.  First, curious as to whether you are still using the same procedure as in your original post?  Using a 12 degree angle on the facing edge seems a bit extreme even though recommended by  Koki Iwahara.  I'd love to try on my knife but wary of trying because would be hard to reverse once started!  Also, handle on my knife is symmetrical so could be sharpened either left or right handed.  But mainly, would like an update if you are still using the settings you describe.


Edited by teascher - 3/10/13 at 9:16am
post #25 of 33

Hi there, what's changed, well first of all I looked at that lovely new knife picture I took took and thought, is that my knife! my knife know has a lovely patina, I did use mustard a couple times in the early days to get it going.  No longer obsessed about keeping it shinny except for the cutting edge/bevel.

 

To be honest I have returned to symmetrical sharpening for two reasons.

1. I got lazy and it was easier to leave my WEPS setup for my favourite knife and not change it.  

 

2. I have moved to Cambodia and can not find a decent cutting board, I am now using a timber cutting board of unknown origins which is just a cross section of a tree, although technically end grain, it is as hard as nails, I can use the meat cleaver and break bones on it and do no damage to the board.  The hard timber is very hard on the blade so I went back to symmetrical bevel.

 

Important changes in procedure:

Naniwa-Chosera 5000 and 10000K Water Stones are brilliant! Only stone I use now.  The 5000K is fast enough to reset a bevel (remember it is a very fine blade so does not take long) if I could afford would probably get some more of their stones in the series. 

 

I am disappointed both 10K stones cracked in the same place, I think adhesive was not applied evenly and left a weak spot, but the crack is like at the end 1/2 inch.  I still use them just avoid the last 1/2.

 

I have tried using the WEPs to push away like Clay does in his videos, but I like the finish by pulling the stones towards/down, if you were sharpening on a traditional stone you would be pushing not pulling the blade along.

 

I also made some balsa wood strops for the WEPS which I matched to the thickness of the Naniwa Chosera stones (pulled out leather glued in balsa) to use 0.25 micron diamond spray (hand america was the best brand use d a couple others no so good more water less diamond particle).

 

Sharpening observations. The knife straight off the 10K is great for tomatoes, I think it still has some micro teeth. If balsa stropped 0.25micron it will lop hairs off your arm without touching your skin, but is too smooth and almost glides along the skin of the tomato, but it is better for cutting sashimi.

 

When I sharpen the blade I just leave the 10K edge on it, its beautiful not too jagged not too smooth, just the right amount of cutting and sawing.

 

Stropping

I used to shave with a straight razor so I put my old style hanging barber strop 3" wide loaded with 0.25 diamond spray to use.  This is another reason why I stopped using the asymmetrical sharpening angles as it easier to do by hand. I prefer the finish on the hanging leather strop over the balsa.  Hang it in the kitchen, yes people always ask what it is, but it only takes a second and a couple passes of the blade to clean up the edge. Off the leather strop it is hair popping sharp again and I not taking a load of metal by putting it on the stones as often.

post #26 of 33

I now use a symmetrical blade because I have a cutting board that is cross section of a tree and is as hard as nails.

 

I only use the Naniwa-Chosera 5000 and 10000K Water Stones now.

 

I also strop on a 3" wide hanging barber strop loaded with 0.25 micron diamond spray (hand american). I use this for touch up only takes a second kind of like steeling the knife. Post leather strop it is hair popping sharp.

 

For tomatos the 10K finish off the stones is great. I push the WEPS, eg opposite way clay demonstrates the use as I have more control and it is like pushing a blade on a traditional stone as opposed to pulling it, reduced wire edge problems too.

 

10K is great for tomatos etc, just enough micro saw teeth.  Stropped on balsa 0.5 and 0.25micron it is super hair lopping sharp, but almost glides over the tomato skin, but great for sashimi though.

 

 

post #27 of 33

Thanks for response, just a further question for clarification.  You mention you've gone to symmetrical sharpening instead of asymmetrical as asymmetrical is too much bother.  Does this mean you are setting the angle to 12 degrees on both sides of the Masamoto?  Or have you changed the angle?

 

Second, you mention sharpening differently from the way Clay does it.  When I've watched his videos it looks like he pulls stones towards him and down.  Also, sometimes he moves the stone both up and down in small arcs as he moves across the blade.  But I gather you are saying you only pull the stones toward you and down, so stones are moving toward the edge of the blade as you go.  Correct?

 

Also, at some point you mentioned not liking the Shun as being stainless steel.  But isn't the Masamoto VG stainless?

 

Thanks for your help!

 

Tom Ascher

post #28 of 33
A symmetric edge on a fundamentally asymmetric blade is only to be considered if you're prepared to rebuild its entire geometry, and not just the very edge. Otherwise, expect in the long run serious wedging and steering issues. These will start to occur after a few sharpening sessions.
Only to be considered IMHO by a lefty willing to use a 'righty' blade, and willing to accept some serious material loss.
I find it hard to see what would be the advantage of a symmetric edge on a hard board. With an asymmetric edge, the contact with the board won't be exactly perpendicular to the apex, but slightly displaced to the right bevel. The edge will make an angle of some 8O degree with the board, by which the apex is somewhat spared.
post #29 of 33

Only the cutting edge was asymmetric not the entire blade, but I did do it over a couple sharpening sessions (talking 1mm maybe 2mm maximum amount of steel here). As for theory and practice, regarding the hard board, I would say my symmetric edge is not as acute as the asymmetric edge was. I did notice some steering but not much we are talking about only the cutting edge not the entire blade symmetry. 

 

The blade is not VG steel. It is white steel #2.

 

I had shuns and did not like the blades, softer and more prone to micro chipping when sharpening and chipping when cutting of course they dont need to be wiped down all the time after use like the the carbon steel does.

 

My cutting angle/bevel varies depending on how I apply pressure on the weps due to the wiggle caused from pushing out or inwards on the pivot on the arms.  Off memory I think it is something like 12.5 or 13 degrees moving towards 13, depending if I use my angle cube at the tip or mid point. I pull the stones down and towards me from the tip.  I find this method a little slower but I use less pressure and get a better bevel because I have control over the wiggle room that the weps has on its pivot (1-2 degrees). I also find the tip has too much flex and too much pressure is applied by using the pushing away method, I do use the clay method/s for resetting bevels and other knives I want to quickly touch up or removing any little chips in the bevel.

 

Polishing:

I did have a mirror finish on my blade for a bit (dremel felt buffing pad and diamond paste (not the spray)) but found food had more suction/stuck to the blade more, buffed it out and allowed a patina to set in and less sticky.

post #30 of 33
If you want to put a symmetric edge on an asymmetric blade, you first have to recenter the edge, and thin the left face. That's rather a major operation that involves a lot of material loss.
The essential characteristic of an asymmetric blade is the edge being off centered. If you put a symmetric edge without recentering it, steering and wedging will occur.
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