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.






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.






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:

[JBroida]

Thanks for the advice, took that to use on the 1k. heres my results:

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.

[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.