And if...

B

brasileiro

Joined
Aug 26, 2011
Messages
250
Ok, some people definitely don’t like sharp edge around here.
I was sharpening a knife for a friend and she complain that was too sharp.
I can teach her how to use the knife and how to clean and store, but I’ll never stay there to check if she is doing right. This is (i think) the main reason some knifes given to me sharp are chipped, dull, rolled...
That said, what is the angle limit to a cutting edge that works for ordinary kitchen knifes job?
And if I use to go to 25, 30... dps in the same tasks would it last longer than 15 or 20 dps knowing that most of people don’t really care about their knifes?

Thanks.
 
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Well, if they're used to using (misusing) dull knives anyway, then they probably wouldn't notice much difference accept that it would definitely feel sharper than what they're used to. A 25 to 30 dps edge should stand up better to the misuse.
 
If the edges are getting quickly dulled by misuse as it is, I'd at least sharpen to a geometry that lets the knife keep working reasonably well after the apex gets trashed. Really wide edge geometries, at 40+ degrees inclusive, hold their shape better, but will never cut very well after the apex itself isn't crisp anymore. For some uses, like slicing tomatos, cutting will cease altogether at such a wide edge angle. If the knives are really being abused, the wider-edged knives won't hold up much better anyway.

In the short-term, I'd suggest sharpening ONE of her most-used knives at something like 30 degrees inclusive (15 per side), and let her get accustomed to how it cuts. Hopefully, she'll come to appreciate how well it works, and more so, if she also then begins to use it more carefully out of respect for that nicely-cutting edge, without wrecking the edge so quickly. Might also be worth buying her a cutting board that won't damage the edge, like poly, to use with the sharper-edged knife.

For her other knives, in the near-term, might just put a 40-degree inclusive edge on them, while (hopefully) she's getting favorably acquainted with the one sharper knife at 30 degrees. If you're lucky, she might eventually ask if you can make the others work as well as the 'good' one. :)

IF a perfectly-crisp, biting apex on a 30-degree edge is still 'too sharp' for her, you can always finish it off by dragging that new, crisp edge lightly (very lightly) across your stone at a 90-degree angle, just to take that intimidating 'bite' off of it, before giving it back to her. The underlying narrower geometry will still make it work pretty well in simple kitchen uses, even if that perfect apex isn't quite so, anymore.


David
 
Well. Now I have a rolled edge.
WdSilBW.jpg

I check many times for burr, and couldn’t see.
20 dps, 1000grit diamond stone, strop at higher angle with green compound.
Misusing or bad shapen?
Is it normal? I delivery it yesterday at luch time, lunch time today and boom!
 
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Try 20-25 dps and stop at a lower grit, maybe 400. Strop only enough to remove the burr but not to polish.

That could also be the result of just a very soft steel. Or a really bad choice of cutting surface. Is she using a hard cutting surface like glass or stone, or perhaps cutting directly on a ceramic plate?
 
danbot said:
Is she using it to chop frozen maple wood? :confused:
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Frozen maple wood I don’t think so, but chicken maybe (when I say chicken I don’t mean the meat I mean slice the parts between bones. I don’t know how you call this) :D
 
jc57 said:
Try 20-25 dps and stop at a lower grit, maybe 400. Strop only enough to remove the burr but not to polish.

That could also be the result of just a very soft steel. Or a really bad choice of cutting surface. Is she using a hard cutting surface like glass or stone, or perhaps cutting directly on a ceramic plate?
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Interesting. I finish a knife with xtreme low grit, one of my knifes and I really fell the edge last longer but was so low that it fells like a saw. I’ll try this too. Thanks.
The steel is unknow. Is like a Tramontina knife.
I ask her about cutting surface and she uses a “plastic” board.
About ceramic plate I don’t doubt that.
 
I'm also wondering what backing surface she's using for chopping. Cutting board (what type?), countertop, etc...

It looks like most of the rolled edge is in the belly portion of the edge, aft of the tip. If so, that looks like the sort of damage I'd expect if slicing or draw-cutting on a very hard surface. I see the same sort of damage on one of my family member's kitchen knives, used on a ceramic tile countertop. And it also happens very quickly, usually in the first use of the newly-sharpened blade.


David
 
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brasileiro said:
Frozen maple wood I don’t think so, but chicken maybe (when I say chicken I don’t mean the meat I mean slice the parts between bones. I don’t know how you call this) :D
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If she is hitting bone with the edge that could cause the edge to roll if the steel is on the softer side. Maybe you could lend her a knife of known steel and see how that holds up?
 
Obsessed with Edges said:
I'm also wondering what backing surface she's using for chopping. Cutting board (what type?), countertop, etc...

It looks like most of the rolled edge is in the belly portion of the edge, aft of the tip. If so, that looks like the sort of damage I'd expect if slicing or draw-cutting on a very hard surface. I see the same sort of damage on one of my family member's kitchen knives, used on a ceramic tile countertop. And it also happens very quickly, usually in the first use of the newly-sharpened blade.


David
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I believe is the same board over a granite countertop. I’ll check tomorrow and give you a feedback.
And yes, it’s the belly. :thumbsup:
Thanks.
 
danbot said:
If she is hitting bone with the edge that could cause the edge to roll if the steel is on the softer side. Maybe you could lend her a knife of known steel and see how that holds up?
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If nothing works I’ll try this too. Thanks.
 
Well, she uses a plastic board over a granite countertop. But watching her to use the knife I saw that:
1-She don’t care about it, she put the knife with forks, and spoon, and other knifes inside the same sink when go to wash.
2-she cuts everything with over pressure than need. IMO. She also cut other things with same knife, I mean, she have 3 or 4 knifes but no one is just to food prep. Last night, she and some friends was cutting plastic bottle.:eek:
3-one thing that I note is that when she is slicing raw potato, almost on the end of the slice act, the belly of the knife hit on the board. Just like chopping but with slice motion. When you are at half of potato the pressure need is higher than the when you start or when you are finishing, keep control of force seems to be difficult because the slice in the half end happen at once.
The issues number 1 and 2 can be solved, but the number 3...?
Is there any other way to slice that differ from traditional one?
 
You will never win.

Set them up with a fairly acute edge finished at very low grit - 120-220 or so, use a hint of a microbevel.

Then ignore them most of the time. Every so often when visiting, sharpen them up on the underside of a mixing bowl and 'steel' them on the glazed rim. Do nothing more. They will never stay sharp, so there is no edge strategy that will work, only recurring maintenance strategies that are easiest for you.
 
HeavyHanded said:
You will never win.

Set them up with a fairly acute edge finished at very low grit - 120-220 or so, use a hint of a microbevel.

Then ignore them most of the time. Every so often when visiting, sharpen them up on the underside of a mixing bowl and 'steel' them on the glazed rim. Do nothing more. They will never stay sharp, so there is no edge strategy that will work, only recurring maintenance strategies that are easiest for you.
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Yeah. That's what I thought.
Im sad now, but what has no remedy, remedied is.
 
brasileiro said:
Well, she uses a plastic board over a granite countertop. But watching her to use the knife I saw that:
1-She don’t care about it, she put the knife with forks, and spoon, and other knifes inside the same sink when go to wash.
2-she cuts everything with over pressure than need. IMO. She also cut other things with same knife, I mean, she have 3 or 4 knifes but no one is just to food prep. Last night, she and some friends was cutting plastic bottle.:eek:
3-one thing that I note is that when she is slicing raw potato, almost on the end of the slice act, the belly of the knife hit on the board. Just like chopping but with slice motion. When you are at half of potato the pressure need is higher than the when you start or when you are finishing, keep control of force seems to be difficult because the slice in the half end happen at once.
The issues number 1 and 2 can be solved, but the number 3...?
Is there any other way to slice that differ from traditional one?
Click to expand...

No easy fix, it sounds like.

If the knife is getting used for anything & everything, including cutting plastic bottles & who-knows-what-else, and tossed loosely into the sink or a drawer to rattle against everything else, there's no saving it from quick edge damage.

As to the potato slicing, I've noticed similar issues with cutting apples as well. Some blade geometries really get squeezed & bound up midway into the cut, in an apple, no matter how sharp or acute the edge is. Friction against the sides of the blade & edges of the spine seems to play into it a lot. Really have to press hard to push it all the way through, so it smacks hard against whatever cutting surface is underneath it. Even relatively thin blades, if they're narrow from spine-to-edge, seem to have some difficulty with that. I've found that a TALL and THIN-as-possible grind, like a thin chef's knife or santoku, works better in cutting them (more chopping cut, than slicing; but if the geometry is good, either seems to work better with such a grind). I've been using 5" santoku a lot lately, for apples. I've really thinned the edge a lot, to a very shallow & polished convex, and it's a joy to use in that application. But it's not set up to take all that other abuse, as described. I take care of it and cover the blade with a makeshift edge protector, when I put it away.


David
 
Obsessed with Edges said:
No easy fix, it sounds like.

If the knife is getting used for anything & everything, including cutting plastic bottles & who-knows-what-else, and tossed loosely into the sink or a drawer to rattle against everything else, there's no saving it from quick edge damage.

As to the potato slicing, I've noticed similar issues with cutting apples as well. Some blade geometries really get squeezed & bound up midway into the cut, in an apple, no matter how sharp or acute the edge is. Friction against the sides of the blade & edges of the spine seems to play into it a lot. Really have to press hard to push it all the way through, so it smacks hard against whatever cutting surface is underneath it. Even relatively thin blades, if they're narrow from spine-to-edge, seem to have some difficulty with that. I've found that a TALL and THIN-as-possible grind, like a thin chef's knife or santoku, works better in cutting them (more chopping cut, than slicing; but if the geometry is good, either seems to work better with such a grind). I've been using 5" santoku a lot lately, for apples. I've really thinned the edge a lot, to a very shallow & polished convex, and it's a joy to use in that application. But it's not set up to take all that other abuse, as described. I take care of it and cover the blade with a makeshift edge protector, when I put it away.


David
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Thanks David. I also take care of all my blades, kitchen blades, pocket knifes...
I almost cried when I saw it that way.
The advice was given and I will try to sharpen as all around job blade but I know that will not last longer, but if last I little bit more is a plus.
 
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