Initial sharpness: what are your expectations?

Curious, what are folks' experience at home with initial sharpness, and how long do you expect initial sharpness to last for your gyutos? (edit: for clarity, I mean initial sharpness off the stones)

For me, the knives I've used fall into a category of either A) initial sharpness lasting one session and the knife slowly loosing sharpness over time, getting by with honing/stropping (depending on the knife) before each prep. or B) Initial sharpness lasting 3-5 of prep-sessions and then dropping to "90%" sharp and staying there for weeks (it can slice cleanly through glossy magazine paper, but not push cut).

I'd like to keep that initial sharpness feel longer before needing a touch-up(s), but I can't tell if my expectations are generally not realistic, or perhaps it's a function of how I'm sharpening (15 degree angle, no microbevel, finish on a 6K grit. Push/pull cut exclusively).

Initial is meaning what exactly? Off the stones or out of the Box?

HRC_64 said:

Initial is meaning what exactly? Off the stones or out of the Box?

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+1 but I'm leaning towards the former

Ah yes-- I meant off the stones. Thanks for asking to clarify.

My expectation is for it to last at least 3 home meal preps without any real perceived loss in sharpness. I expect this for any steel type but some go for much longer. What I mean by that is it performs well through most product as well as when the edge is fresh. I do not do test cuts on things like paper, etc. When I notice the knife not performing to this standard, I strop or sharpen on a finisher. If that doesn't do it, I step back in a progression to raise a burr and then finish. I have a lot of stones, so I'm not consistent with my finisher for a specific knife and my approach is not scientific. I love sharpening, so I don't mind an edge not lasting forever, but at a minimum, I want 3 home prep sessions.

Prep sessions as in "dishwasher top rack will be infested with mise bowls"?

My definition of "totally dulled" is "can't be stropped or honed into slicing into a sponge" (1), "passes that but will give you tomato trouble" (2), "reasonably sharp" (3) is "push cuts easily into a corner of that sponge with no more instinctive slicing than using a well maintained nakiri. Usually shaves arm hair with skin contact, sometimes uncleanly", "damn sharp" (4) is "you can push the edge flat against a sponge surface with several cm contact length, and with a bit of force it will cut in without any slicing. Tends to go for hair off-skin."...
It also keeps me from having a bachelor kitchen full of old dirty sponges. They're cut up sooner, given I tend to give knives a quick test before putting them back in the block.

I rarely let it come to "totally dulled". A few regularly used knives I have can be kept "reasonably sharp" (3) for a couple months (but that includes crox stropping and/or ENAT touchup a few times). They are either white steel (not all white steel by a long shot!) with a rather acute edge (12dps-ish) or good VG10 with a conservative, well microbevelled edge. I found blue steel and ZDP can more easily get stuck in a sulk of (2). As for the "plebeian" steels, I've come to expect more of good 420B-ish than bad 1.4116-ish.

dwalker: Thanks-- that corroborates what I experience as well.

LifeByA1000Cuts: I like your scale. What's the experience after sharpening? For example, say if you are done sharpening and your knives come off at at 4 (I'm making a guess), on average how soon does sharpness drop to a 3?

dwalker said:

My expectation is for it to last at least 3 home meal preps without any real perceived loss in sharpness. I expect this for any steel type but some go for much longer. What I mean by that is it performs well through most product as well as when the edge is fresh. I do not do test cuts on things like paper, etc. When I notice the knife not performing to this standard, I strop or sharpen on a finisher. If that doesn't do it, I step back in a progression to raise a burr and then finish. I have a lot of stones, so I'm not consistent with my finisher for a specific knife and my approach is not scientific. I love sharpening, so I don't mind an edge not lasting forever, but at a minimum, I want 3 home prep sessions.

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Exactly, I just wait for the knives to have a slight resistance through food. I expect all of my knives to be razor sharp all the time. Then touch them up on my 3K or 4K stone. I can get about 2 months out of my main prep knives because I interchange between a santoku and 150mm petty (both VG10). However, I'm only chopping vegetables. I have a cheap gyuto (made in China) for cutting harder fruits like pineapples and watermelons.

I find that one of the best veggies for showing up a tiring edge is the humble green bean.

unprofessional_chef: Got it-- make sense. When do you find yourself doing your first touch up (after a round of sharpening where you actually raise a burr)? Also, I'm curious to know which which 3K stones you use.

Nemo: That is a good test

bookgeek97 said:

unprofessional_chef: Got it-- make sense. When do you find yourself doing your first touch up (after a round of sharpening where you actually raise a burr)? Also, I'm curious to know which which 3K stones you use.

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I never go through a full sharpening on my knives because I never let them get too dull. So I'm always doing a touch up to remove as little steel as possible and always raise a burr so I know I've hit the apex of the edge. Then strop on stone to remove the burr, exposing new steel and new edge. If I want a coarser edge bigger bite I use the 3K Chosera. But I mostly use the 4K King stone now which leaves a much finer mirror finish.

@bookgeek Very dependent on usage - (4) does not tend to live long on a practical cutting board, and it is something I will only really care to go for on anything that is good carbon steel and/or single bevel, but if the knife is used for gentler off-board stuff, crox on balsa can restore it a couple times** For delicate edges, I find boards make a huge difference indeed - bamboo or composite can send a carbon steel usuba to (2) in a jiffy while a 15dps gyuto will be fine for quite a time; on the other hand, my cheap 420B yanagiba - within the limits of the edge angles it can take - is relatively "long lived" since I use it mostly as a dough/veg slicer with hardly any impact...

BTW, one trap not to fall into: While scrubby implements are known to be good burr removers, using them to clean already-used edges tends to damage them *really* quick.

And I guess perceived edge retention depends a lot on how tolerant one is of some duller spots in the edge, whether one works around them instinctively or gets tripped up by them.

My expectation of an uncomplicated, use-often chef knife or cleaver would be to survive at (2) after making 500-1000 slices of rhubarb stalk*, on a friendly (eg acacia) board. Even a 420J2 cleaver can do it, but funny enough many OOTB edges, also on better steels, won't.

*I hate rhubarb crumble being too fibrous.

**If you never tried it, be careful with arm hair tests or on towards-the-thumb paring tools - that stuff can make an edge take very little effort to cut into skin. Normally, one would consider it a technology used to maintain razors, not knives.

@Nemo old, tough green beans can become more of a geometry test though - don't rely on an edge being dull if a knife you don't know well seems to fail that test

unprofessional_chef: thanks. I was thinking about the 4K by King, so that is good to hear that's working out.

@LifeByA1000Cuts: Thank you, and make sense. To your point, i'm really not sure if my expectations of perceived edge retention (right off the stones) too intolerant, or alternatively if I really need to figure out a more robust edge for durability. That said, on a separate note, I wouldn't have guessed that sponges with a scrubby/abrasive side could damage an already-used edge-- I don't strop on the sponge (as if I were removing a burr), but I definitely use it to clean.

LifeByA1000Cuts said:

@Nemo old, tough green beans can become more of a geometry test though - don't rely on an edge being dull if a knife you don't know well seems to fail that test

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By geometry, do you mean thickness immediately behind the edge increasing the resistance to cutting?

unprofessional_chef said:

I never go through a full sharpening on my knives because I never let them get too dull. So I'm always doing a touch up to remove as little steel as possible and always raise a burr so I know I've hit the apex of the edge. Then strop on stone to remove the burr, exposing new steel and new edge. If I want a coarser edge bigger bite I use the 3K Chosera. But I mostly use the 4K King stone now which leaves a much finer mirror finish.

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If you expose fresh steel fatigued steel got abraded. If you never perform a full sharpening -- i.e. starting behind the edge -- your edge will get thicker and thicker.

Benuser said:

If you expose fresh steel fatigued steel got abraded. If you never perform a full sharpening -- i.e. starting behind the edge -- your edge will get thicker and thicker.

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The idea is to remove a very very small but even amount of steel along the entire width of the bevel. It's in the order of micrometers of steel being removed. When I do this it removes a small amount of steel behind the edge as well. I preserve whatever factory angle the knives came with. I don't feel there is any need to change it.

Full sharpening or sharpening too often with coarse stones will result in a thicker edge much faster than what I'm doing.

unprofessional_chef said:

The idea is to remove a very very small but even amount of steel along the entire width of the bevel. It's in the order of micrometers of steel being removed. When I do this it removes a small amount of steel behind the edge. I preserve whatever factory angle the knives came with. I don't feel there is any need to change it.

Full sharpening or sharpening too often with coarse stones will result in a thicker edge much faster than what I'm doing.

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I feel like you don't understand what was being meant by full sharpening. Aka thinning behind the edge and then resetting the primary bevel.

In your scenario, this full sharpening is going to be required at some point. It's a pure case of geometry... but I think we all agree that your touch ups/general sharpening is done on high grit stones with minimal material removal so as to preserve the life of the knife...

Though some would advocate that whatever you do to the primary bevel you do to the secondary bevel/shinogi/whatever is present on your knife and you will rarely need to get your super course stones out.

You're talking about this. Which I do fully understand. But the way I maintain my personal knives it'll take a decade or more before I get to that point. I haven't gotten to the point where I need to do a full sharpening or a need to reset the primary bevel on my personal knives.

But knives I sharpen for my friends and family with unknown history that haven't been maintained, that have been abused, or have a lot of fatigued steel because the edge is rolled over. Yes, I would do a full sharpening on coarse stones every time. I guess it would depend on the condition the knives.

[video=youtube;3jsTtnidY3w]https://www.youtube.com/watch?v=3jsTtnidY3w[/video]

Initial sharpness? Means 2 different things to me. Cutting very thin in-hand or slicing with only tip contacting the board means near razor-edge, which in home use I will refresh about once a month with an R2 blade. On the board, initial sharp is gone when I can't "effortlessly" fine-mince herbs, and with an appropriate pm steel that can be at least 2 weeks between touch-ups. Touchups means a few light strop-strokes on a fine stone. I don't think I'm as hard on knives as most folk, who do much heavier board work.

rick alen said:

On the board, initial sharp is gone when I can't "effortlessly" fine-mince herbs, and with an appropriate pm steel that can be at least 2 weeks between touch-ups.

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Dang, I lose initial 'board' sharpness within a couple of hours at work... even with PM steels.
Either I have high standards or I need to revisit my sharpening fundamentals! :O

Kippington said:

Dang, I lose initial 'board' sharpness within a couple of hours at work... even with PM steels.
Either I have high standards or I need to revisit my sharpening fundamentals! :O

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Ahahaha, I'm talking home use, like a few minutes a night, as well as PM steels, so your experience sounds about right to me.

my at home use, the sharpness off the stone lasts about 3-4 weeks. usually 4 or 5 strokes a side on a 1200 diamond hone is enough for another 3-4 weeks. I don't worry about thinning, as made the blades are monosteel, 1.5" tall, thickness 0.06" at the spine, 0.025 1/2" above the edge, and 0.01" 1/4" above the edge. my wife's knives need the hone about every other week as she is a bit heavy handed when cutting.

Fresh off the stones I expect my knives to cut the Grim Reaper to make him pay for trying to take my soul.

Fresh off the stones I expect my knives to kill a bear cub easily in close combat.