My nenox suji developed a birds beak!

[Boondocker]

I noticed it a month ago, and its been bugging me so I decided to dig out my 220 sun tiger and see what I could do about it. I have no idea how it formed in the first place.

http://img.photobucket.com/albums/v478/lilmartin/2012-01-17_12-45-57_90.jpg

http://img.photobucket.com/albums/v478/lilmartin/2012-01-17_12-45-14_156.jpg


I spent about 20 minutes on the coarse stone while I was making lunch. I lost a couple mm of knife length when i slipped off the stone and snapped the tip off, but the blade edge looks more like it should now I think.

http://img.photobucket.com/albums/v478/lilmartin/2012-01-17_13-23-48_56.jpg

http://img.photobucket.com/albums/v478/lilmartin/2012-01-17_13-23-40_187.jpg


Haven't taken it to any higher grit stones, yet. Might as well reprofile my minamoto slicer and thin my masamoto gyuto while I have the coarse ready to roll.

[Pensacola Tiger]

You create a "bird's beak" when you sharpen incorrectly.

When you sharpen, you need to lift the handle as you near the tip to maintain the angle of the bevel, not the angle of the knife.

[kcma]

what PT said, it's formed because you made it ;) aside from slight lift, you also need to adjust angle of blade to stone ratio. it's a continuous adjustment, because the curve is continuous. around mid point of your curve, your blade will be about perpendicular to the stone, and by the tip, the handle will actually be in front of the stone not close to your body (that's how the beak forms, can't reach the tip. spend enough time on most jigs, beak forms too).

[Boondocker]

Thanks for the advice, took that to use on the 1k. heres my results:
http://img.photobucket.com/albums/v478/lilmartin/2012-01-17_16-16-45_926.jpg
http://img.photobucket.com/albums/v478/lilmartin/2012-01-17_16-16-22_504.jpg

[JBroida]

Thanks for the advice, took that to use on the 1k. heres my results:
http://img.photobucket.com/albums/v478/lilmartin/2012-01-17_16-16-45_926.jpg
http://img.photobucket.com/albums/v478/lilmartin/2012-01-17_16-16-22_504.jpg

it seems like you're still having the same technique issue in your sharpening... the tip bevel is getting smaller towards the tip and you are creating a flat spot that will later turn into a birds beak again.

[heirkb]

Watch this video: http://www.youtube.com/watch?v=tmBTO0cA_qw

Should help.

[Boondocker]

Thanks for the input, heres where I got to today after polishing it up for work. I'll have to make a second pass at the tip on sunday during football.

http://img.photobucket.com/albums/v478/lilmartin/2012-01-17_16-39-58_469.jpg
http://img.photobucket.com/albums/v478/lilmartin/2012-01-17_16-38-48_515.jpg

[doug8066]

Hi Boon,
You still have the birds beak.
I suggest you "sharpen" just the tip area of the knife (eg the last half inch or so), with extra sharpening towards the very tip. Do this on a coarse stone. What you are doing then is actually re shaping the profile of the tip area of the knife.
This means that you are going to have to remove quite a bit of metal from this area, especially towards the very tip, without removing any more metal from the rest of the blade. This sometimes requires quite brutal work on the tip to bring it back "in line" with the curve of the rest of the blade. At first you may think you are wrecking the knife, but this excess metal must be removed.
Once the coarse ripping away of metal is done, your blade profile should be back to a nice progressive curve again. THEN you can start your usual sharpening process to remove all those horrible scratch marks, and produce a nice bevel and cuting ege.

[JBroida]

actually, the easiest and quickest way to fix it on stones is to grind at near a 90 degree angle and reshape the edge... then sharpen until the entire edge has a burr (the area where you reshaped will take longest, so thats what you're waiting for). Also, its important to use proper technique or you'll just make another birdsbeak.

[doug8066]

actually, the easiest and quickest way to fix it on stones is to grind at near a 90 degree angle and reshape the edge... then sharpen until the entire edge has a burr (the area where you reshaped will take longest, so thats what you're waiting for). Also, its important to use proper technique or you'll just make another birdsbeak.

Well said J.

[Boondocker]

my chef told me years ago I'd mes a few knives up learning, didnt think it would take years to manifest though

[Keith]

what PT said, it's formed because you made it ;) aside from slight lift, you also need to adjust angle of blade to stone ratio. it's a continuous adjustment, because the curve is continuous. around mid point of your curve, your blade will be about perpendicular to the stone, and by the tip, the handle will actually be in front of the stone not close to your body (that's how the beak forms, can't reach the tip. spend enough time on most jigs, beak forms too).

Exactly right it is a continuous adjustment starting at the begining of the curve leading to the tip,finishing as you said.This goes for Gyuto & Yanagi,thin tiped yanagi are prone to bird beaks & broken tips.

Sharpening on dished stones is also not good for tip work & can mess up the urashi on a japan single bevel.

[kcma]

Clearly it didn't sharpen enough ;p I got my first beak fast lol. I find the best fix is to just profile and break of tip. Then sharpen.

If you look at the tip, it makes sense that you have to swing your elbow out. Other wise, you can't reach the tip. Lifting knife works, but isn't ideal. You are changing angle to something very obtuse. Combination of the two work best.

[LennyD]

Question for you all about how this actually happened in the first place.

I think I understand the suggestions for repairing it, but maybe since when I have screwed up tips myself it has always been in the opposite direction and actually ground off too much of the tip (a problem I had for years with most non kitchen knives with softer steels and rounded or drop points etc) which actually made the tip more upwards. So this whole birds beak thing is somehow confusing to me.

Was the edge sharpened at too low an angle just before the tip itself, and/or sharpened at too high an angle at the very tip?

Actually in the past on some of my cheaper folders (softer Chinese steels) the blades would get shorter in length rather than height, and it took a while to stop doing that lol.

Also is the difference of the width of the edge along the knife length in this sample in the pics here what is indicating to you what the problem is?

Sorry for all the questions, but it really has me curious, and maybe can help the OP as well.

Thanks

[Keith]

Yes it is partly because of the width,it is both thinner & less steel fr. cutting edge to spine.Less steel period.I find that lifting spine a little at begining of curve,little more near the tip,& finish the tip a little higher in an arching motion.If you look at the polish line it is wider at the heel & flatter part of cutting edge,gradually getting more narrow towards the tip.

A sugi has less steel than a gyuto,in a production kitchen they wear down pretty fast.I have gone thru a couple of those things.Correct tip sharpening will prolong the life of a sugi.I have found that I can do most sugi jobs better with a Yanagi.Also this only occured with my sugi's as they got worn down my fingerpads would get thin skin or a little blood because there was not enough steel left between my fingers & the stone.

Since I got into my first Yanagi yrs. ago,I have no use for those blades no need

[Boondocker]

I've always thought about getting a small yanagi for the line, but was always under the impression that they were best used on only raw products (I have seen them used to slice terrines as well). I haven't seen one used for slicing seared meat though.

[Octaveman]

This is what I do every time I sharpen. Put the last 5-10mm of the tip down and sweep the blade in the motion shown in the pic raising the handle as your finish the motion.


http://i22.photobucket.com/albums/b346/octaveman/tip-1.jpg

[Keith]

I've always thought about getting a small yanagi for the line, but was always under the impression that they were best used on only raw products (I have seen them used to slice terrines as well). I haven't seen one used for slicing seared meat though.

A sharp yanagi is good for seared meat(no bone of coarse,& no twisting of the blade)they are exceptional slicers.Just for the heck of it about 3 yrs. I bought a 210 Kobuyashi blue steel yanagi for around 100.00.I keep this blade at my wifes antie's house & prep entire meals with it.Using just the kobu & nothing else.

Thanks in part to KCMA & some other members I have become a single bevel japan style knife junkie I love these blades & I love to sharpen them.Some of these Japan Gyuto if you look wt. a loop are almost flat on the backside & ground bevel on the right.I gave my niece a single bevel gyuto & taught her husband how to sharpen it,only one burr to remove simple.

[jmbullman]

I had a 240 Fujiwara carbon come in with a "birds beak" from the factory and the other side was barely touched, I just hit the stones and matched it and it cuts like a knive through butter. Mistakes happen to everybody even from the factory, I figured mine was sharpened on a Friday at 4:30 and the saki was getting warm, not to much harm so no fOul I just delt with it. If that is your only mistake in knife sharpening than u are a lucky man! Peace and good job fixing it. Jmbullman

[stevenStefano]

It can be tricky to sharpen the tips of some knives. I know my angle is wrong if I see a large flat area just back from the tip and adjust the angle. I sorta try and point the tip into the stone and move it back and forth if that makes sense

[Keith]

Also it's important to remember in tip sharpening,press only on pull stroke,at a higher angle a tip can gouge the stone on the return stroke with incorrect tech.

[Boondocker]

Also it's important to remember in tip sharpening,press only on pull stroke,at a higher angle a tip can gouge the stone on the return stroke with incorrect tech.

Did that a couple times at first. I also have a nice imprint in my fingertip still from the tip of that knife ;)

I have to say, I thinned my nenox a bit too when I took it to the coarse stone and I am amazed what a difference making a moderately more accute angle on the edge did for slicing triple seared strip loins tonight. Did 50 orders tonight for a banquet, no need to saw and the knife still had plenty of bite to it in the end - didn't even get to try my minamoto I had waiting in the wings as a backup (with a giant shiny new bevel as well!) I may pick up a nice blue steel short yanagi eventually to replace on of the slicers then if it would work on something as charred up as the triple seared beef gets

[ksskss]

It's like a bad golf swing.

First you need to envision the correct shape for the knife without the bird's beak. If you need to, sketch it on the knife. Then see where there's too much metal and concentrate on those areas. Get a dead flat surface. hold the knife perpendicular to it and roll it towards the tip. As you do this see where you can pass a sheet of paper under the blade. If you have to, get that first approximation of the correct shape doing as Jon suggests. It's more work, but you have a better chance of success and I'd recommend it.

This isn't really a problem with jigs or bringing the knife up at the end of the stroke etc etc. It is primarily a problem of not following the shape of the knife and grinding an even amount initially. To correct it you have to focus on the areas that didn't get ground enough in the first place. I hate to see a nice knife like this get trashed. ON PURPOSE make a bird's beak on a junk knife and fix it a couple times before you turn this into a petty.

You should be grinding in a direction perpendicular to the tangent of the CORRECT curve along the length of the blade.

If you look at Bob's (Octaveman's) picture, note that it essentially shows a similar shape perpendicular to the blade's path of the correct edge profile. This is correct and it is no coincidence that the J shape looks like a knife edge. I'll leave the math for another discussion. You can choose to do knife raising or more simply angle the stone and rotate the blade in the same plane rather than raising it. This is ergonomically simpler and inherently more accurate.

---
Ken

[LennyD]

Yes it is partly because of the width,it is both thinner & less steel fr. cutting edge to spine.Less steel period.I find that lifting spine a little at begining of curve,little more near the tip,& finish the tip a little higher in an arching motion.If you look at the polish line it is wider at the heel & flatter part of cutting edge,gradually getting more narrow towards the tip.

A sugi has less steel than a gyuto,in a production kitchen they wear down pretty fast.I have gone thru a couple of those things.Correct tip sharpening will prolong the life of a sugi.I have found that I can do most sugi jobs better with a Yanagi.Also this only occured with my sugi's as they got worn down my fingerpads would get thin skin or a little blood because there was not enough steel left between my fingers & the stone.

Since I got into my first Yanagi yrs. ago,I have no use for those blades no need

That makes sense, and I still have a slightly wider polish line on my first gyuto from when I first sharpened it and did not realize I was forgetting to compensate for the thinner parts closer to the tip. It did get sharp, but did not match the rest or normal grind/profile of the knife. it is only a cosmetic issue now, and eventually will be gone from future sharpening, but was an inexpensive lesson.

I know it is a subject for another thread etc (I think there are more than one anyhow) but am I reading you correctly that you have given up on a Suji for a preference of using a yanagi? How did that come to be, and any other thoughts?

I still am needing to pick up a slicer of some kind, and much as I really like the idea of the yanagi for many reasons (one even being it is different, and how to compare without trying etc) but somehow due to being practical always seem to revert back to the suji when comparing etc.

[Keith]

I am not knocking the Sugi in particular,I am sure some people love their Sugi's.Along time ago I used my Masa sugi's for slicing duties.Since they start out thin to begin with after about a year of banquet duties & at least once a week on the stones,they get very thin & impractible to use anymore.I turned two of them into thin slivers.After that I got my first quality Yanagi a Suisin 270.There was no turning back,esp. for ahi sashimi & sushi topping there is no compareson.Soon after I got it I was blocking yellow fin quarters & cutting all the sashimi at the hotel.

I got the yanagi out of disatisfaction with the sugi.It was the start of my passion for Japan style blades.

[Boondocker]

After a few months of technique altering I'm happy to announce the birds beak is almost all gone on this knife, still has a slight flat spot near the tip but its almost gone :) and to think, I almost replaced this amazing piece of metal

[thombrogan]

That's great news, Boondocker! Those knife-addicted guys from LA (and HI, NC, NZ, FL, and...) are onto something and I'm glad they shared and you're still enjoying your Nenox goodness.

[kcma]

I am not knocking the Sugi in particular,I am sure some people love their Sugi's.Along time ago I used my Masa sugi's for slicing duties.Since they start out thin to begin with after about a year of banquet duties & at least once a week on the stones,they get very thin & impractible to use anymore.I turned two of them into thin slivers.After that I got my first quality Yanagi a Suisin 270.There was no turning back,esp. for ahi sashimi & sushi topping there is no compareson.Soon after I got it I was blocking yellow fin quarters & cutting all the sashimi at the hotel.

I got the yanagi out of disatisfaction with the sugi.It was the start of my passion for Japan style blades.

I started on yanagiba, then I used suji and thought, wtf, and never entertained the idea of owning one.... Properly used, yanagiba is just better.

[Boondocker]

I'd never want to go through the pinbones on 40ish # of 1-2lb whitefish every week with a yanagi though, I think the suji has a little more durability without chipping in that task. For straight up slicing I want a 270 yanagi though :)

[kcma]

Pin bones are taken care of by debate :-P breaking fish down in general. But yes, suji are more durable

[Boondocker]

The way chef wants me to break down salmon and similarly built fish requires a suji, and until I can get a better yield than that with a deba I'm using a suji for it :)

[kcma]

Break down salmon with a debate the same way you use a suji. That's what everyone do. Salmons body structure isn't San mai friendly.

[Boondocker]

It sure isn't, ill give it a shout with the next salmon we get in

[kcma]

Just make sure your debate is long enough for the salmon :-P 180 won't really want to do a 25# fish :-P

[schanop]

Autocorrection is quite funny sometimes.

[Boondocker]

I think it would work for the river salmon we are getting in right now though

[kcma]

Oh fun! I need to get my restaurant open already,oyyyy getting bored.

[Boondocker]

When what and where are you opening???

[kcma]

just signed a lease last week, not negotiating to take up the adjacent space :D hoping for oct :D it'll be tonkotsu ramen, with better rice dishes than the half ass stuff ramen shop always put out, and some fun quirky stuff :)

[Boondocker]

Very nice, sounds fun. Best wishes and good luck to you

[Stimpy]

Yeah it's still F'd up. :(

[Boondocker]

Been almost a fulll year since I first posted this. Almost got rid of it. my technique has improved drastically thanks to this thread http://img.tapatalk.com/d/13/01/16/8yvy5a9y.jpg

[thombrogan]

Looks so much better. Odd considering it was such small part of edge.

[Boondocker]

The front quarter of the knife is really really thin now. Starting to look like my chefs old masamoto slicers