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Puzzled!

Mon Dec 03, 2012 4:14 pm

Im having a strange problem with my takayuki sakai. It will sing through paper, pop hair off my arm and do whatever else I tell it to until I have to dice some onions. Im seeing alot of resistance on my downward stroke. Seems like a bit of a paradox, should I attempt to thin it out? Im going from a 1k to 3k and have had good results in the past with other knives. Scratching my head.

Re: Puzzled!

Tue Dec 04, 2012 2:14 am

Tell us your sharpening routine in a little detail and that will help us figure out why the knife won't cut onions.

Re: Puzzled!

Tue Dec 04, 2012 9:00 am

Mark, I sharpen very similar to yourself. Begin with my 1k starting at about 10 strokes on each section of the knife from heel to tip and going down in intervals of 2 per set, deburr using a cork and repeat on the 3k. im using about a 15 degree angle and I make it a good point to keep as good of posture as I can. Again, the tip will go through paper like nobodies business and do pretty much every other parlor trick but whenever Im applying some downward pressure on something (say an onion) it gives me a whole bunch of fuss about wanting to cut cleanly. Any insight would be greatly appreciated.

Re: Puzzled!

Tue Dec 04, 2012 1:58 pm

Is the knife still sharp after the onion test?

If so, it's probably not a burr.

Best thought is to try and thin the shoulder a bit.

Re: Puzzled!

Tue Dec 04, 2012 4:40 pm

Yes, the knife still preforms well at any other task that doesn't require me to apply any sort of direct downward pressure. The tip will "draw" through any other food items with ease.

Re: Puzzled!

Tue Dec 04, 2012 7:36 pm

Sharpness starts the cut and geometry will finish it. If the knife is Sharp then geometry is the problem.

Smooth the shoulders of your bevel and see if that helps.

Re: Puzzled!

Wed Dec 05, 2012 2:18 pm

Yeah, it's most like a thick shoulder.

Re: Puzzled!

Wed Dec 05, 2012 11:20 pm

Thanks for all of your help fellas.

Re: Puzzled!

Sat Jan 26, 2013 5:14 pm

i'm having similar problems with sharpness tests vs actual kitchen use (great on tests/not great for lengths of time in kitchen use) and great on drawing through/not great on downward cuts. can someone explain how they go about adjusting the shoulders of the bevel like is being said?

Re: Puzzled!

Sat Jan 26, 2013 7:07 pm

The shoulder is the area where the blade grind meets the edge bevel.

Stock Artifex knife, you can kinda see the angle where the edge bevel and blade grind meet:
Image

Thinned and convexed the edge. See how the blade grind goes smoothly into the edge bevel and there isn't a sharp angle or shoulder?
Image

Sharpness tests test the edge itself, cutting tests the geometry of the blade, which includes the grind of the blade and edge and how they meet.
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