How to dull a knife?

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JASinIL2006
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How to dull a knife?

Post by JASinIL2006 »

I'm trying to think of a way to ask this without it sounding like a dumb question, but I'm not having much luck, so I'll just jump in:

How do you make a knife dull without really screwing up the edge? I'm learning to sharpen and I have an inexpensive carbon steel knife (a Daovua leaf spring gyuto) that I bought to use for practicing. I'd like to take off the edge without ruining it. I thought about maybe dragging it across a coarse sharpening stone, but I'm not sure if that might gouge the stone.

If you've purposefully dulled your knife, how did you do it?

Thanks!
playingfetch
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Re: How to dull a knife?

Post by playingfetch »

I'm learning to sharpen too (moving away from my lansky) and I use my concrete driveway to dull the practice blades. A few back and forth slicing motions will do the trick. A brick would be just as good.
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Re: How to dull a knife?

Post by d_rap »

Yeah and the only thing I what add is use a reasonably fine-grained surface rather than something that's uneven or pitted, which could actually cause chipping. You can use a diamond plate with a couple of gentle strokes or you can even use the side of a stone. If it's a brick or something like that make sure it isn't gouged, because you can cause unnecessary damage.

There are some YouTubers who are very good sharpeners like Jeff Jewell who do this fairly systematically first in order to then put a "fresh edge" on a blade.
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JASinIL2006
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Re: How to dull a knife?

Post by JASinIL2006 »

Good advice, thanks! I'll see if I can find a brick or section of concrete that's smooth and use that, or maybe the side of my 320 stone.

Thanks again!
Radar53
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Re: How to dull a knife?

Post by Radar53 »

For me, I just place the edge vertically onto the side of say a 500 grit stone and make a few pull and push strokes with probably P2 or P3 pressure on Peter Nowlans scale
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Re: How to dull a knife?

Post by ken123 »

How dull do you want it? A few strokes with even a moderaterly coarse stone (1k) can dull a blade. Test your edge's ability to push cut to calibrate dullness.

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Re: How to dull a knife?

Post by jmcnelly85 »

Repeatedly cut cardboard counting the number of cuts, use this as a gauge for edge retention while practicing sharpening strategies and building muscle memory.
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Re: How to dull a knife?

Post by Wjhunt »

My favorite way to dull a knife is to cut food with it. I guess that you could pick up a 12x24 inch tile from the depot to use as a cutting board to speed up the process. It was painful to type in the last sentence.
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Re: How to dull a knife?

Post by d_rap »

Cut an acorn squash into wedges, stem on?🤣
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Re: How to dull a knife?

Post by Tostadas »

You can use the sides of your stones if you dont want to scratch up the face. I sometimes do that for reprofiling to remove chips
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Re: How to dull a knife?

Post by David_R »

Pull the edge of the knife across a sharpening stone at 90 degrees to the stone, along the edge, not across it. Lightly is fine - light enough to not damage your stone. Or as Tostadas wrote, use the edge of the stone. 2-3 times across a stone and you will have a quite dull edge that requires sharpening and not just stropping to get back to sharp. When doing this you're removing the narrow apex of the edge and flattening it. It doesn't take much to grind off that very narrow apex of 1 micron or less for a sharpened knife.

If it helps, imagine a 30 degree angle, and then just barely flattening it at the peak.
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Re: How to dull a knife?

Post by ronnie_suburban »

Give it to my wife! :lol:
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