- Joined
- May 3, 2011
- Messages
- 9,782
- Reaction score
- 4,499
Could it have to do with burr remnants? Not to discuss your sharpening, but the first reason I had to look for finer stones was in a more complete deburring.
How sharp is too sharp?
- Thread starter WhiteRabbitAgain
- Start date
Help Support Kitchen Knife Forums:
Benuser:
"Could it have to do with burr remnants? Not to discuss your sharpening, but the first reason I had to look for finer stones was in a more complete deburring."
I was just typing the same thing.
A finer stone means a sharper edge assuming the steel and geometry can handle it. But a finer stone is much easier to deburr with. So some of what you are seeing could be just more effective deburring regardless of what's happening at a microscopic level at the apex.
Last edited:
One thing to keep in mind is that finer stones are more forgiving. Coarser stones will highlight our inconsistencies much more.
I think that part of what people mean when they say "teeth" is that they want a particular tactile feedback from the product they are cutting. For instance if you are cleaning silverskin off of beef. If you go up much higher than 2k you will lose some proprioception as the knife slides through the product. It becomes more difficult to "feel" the difference between sinew and protein because the knife goes through both the same. Or when chopping veg. Some people really like that "fall through food" feeling, or lack thereof. And I tend to think of what people describe as "toothier" edges on the opposite end of the spectrum from super-refined. You can use this edge to cut anything you like. It will do fine with t But, in the same kind of way, in my experience, this type of edge can be annoying if you are doing something that requires you to differentiate between two textures. Like removing veins and pith from bell peppers or cutting corn off of the cob or skinning salmon.
For me, for board contact knives, the sweet spot is around 2k for synthetic. Above that sticks in the board. It slices towels easier. It is more fragile. It cuts your fingers for in-hand work. And it does not improve retention for heavy board contact. I find pasted strops are even worse for creating these kinds of edges. Naturals are a whole different can of worms. They don't tend to create that industrial laser touch-killing crazy sharpness. Edges tend to be more balanced performance wise, last longer, and are easier to touch up without going through a whole progression again.
I don't know much of anything about the newer diamond tech.
Yeah, mostly. But soft steel on a fine hard stone can jack an edge very quickly too. You can improve the edge on soft stainless with a fine hard stone (like a hard Arkansas or razor Nakayama). But you can also roll or round the edge pretty easy.
For me, for board contact knives, the sweet spot is around 2k for synthetic. Above that sticks in the board. It slices towels easier. It is more fragile. It cuts your fingers for in-hand work. And it does not improve retention for heavy board contact. I find pasted strops are even worse for creating these kinds of edges. Naturals are a whole different can of worms. They don't tend to create that industrial laser touch-killing crazy sharpness. Edges tend to be more balanced performance wise, last longer, and are easier to touch up without going through a whole progression again.
I don't know much of anything about the newer diamond tech.
Yeah, mostly. But soft steel on a fine hard stone can jack an edge very quickly too. You can improve the edge on soft stainless with a fine hard stone (like a hard Arkansas or razor Nakayama). But you can also roll or round the edge pretty easy.
If finishing grit weren't important and people just liked finer grits because it masks deburring technique, I don't see why people would sometimes prefer coarser finishes, which they do.
Most likely you have refined your technique in a way that let's you specifically get the best results using finer stones. That's my guess.
At the same time though. It is much easier to get the finest possible apex using progressively finer stones. Given the person isn't making mistakes along the way.
It's just a matter of realizing that with knives from the steel, to the edge itself there are many variables in just about every aspect of it. A lot like life itself, there are rarely ever black and white answers, and there is usually a kit of grey in between.
I don't think anyone is necessarily saying that finishing grit doesn't make a difference. Speaking for myself, I think what I'm saying is maybe people's expectations of what a finishing grit will do as far as perfomance are a bit off.
I think with all things being equal, and in a perfect world where inconsistent angles, problems with pressure, and something that hasn't been brought up much in this thread which is keeping the stone completely free of slurry, and swarf when finishing especially on lower grit stones weren't factored in, and an absolutely perfect apex was achieved on a knife with the only difference between them being the finish. The actual differences wouldn't be very drastic at all.
There are differences for sure though. I agree with @stringer The things mentioned about tactile feedback are there. Also, how a scratch pattern can accentuate the properties of certain steels are there too. They just aren't these giant night and day differences.
People are strange
BoSharpens
Well-Known Member
With 60 years of knife sharpening along with my machine shop work, I've come to a couple conclusions on metal edges. I have no way of proving if anything I do is "right" but it seems to work OK for my customers. The few that are really touchy seem to appreciate my work, though I don't work on custom Japanese knives. Shun and similar are all I do.
1. Heavy pressure of grit on steel can induce fractures that later give way to a chip & those fractures are not always visible.
2. Light pressure obviously induces less friction & heat where heat on a very fine edge can do hidden damage.
3. When you get down below a .001" thick edge, causing the edge to "work back and forth" with each flip of the blade can start to work harden the fine metal edge with unknown effects.
People tend to think that hand held stones can't generate enough heat to cause a problem, but when you are down below .001" thick edges and you push hard, you simply do not know the actual temperature you generate & stresses you induce in the metal on the actual edge and what it does to the microstructure.
I suppose it is possible someone has actually used some super sophisticated instrumentation to find out, but I've not heard of it. It would be fun to know.
I do know that if you want a super reliable "ground" surface on cooled surface grinders you have light pressures by way of very light down feed rates or you literally get burn marks.
I use extremely light forces and consistent angles in making very fine edges.
On extremely thin edges a fingernail's pressure on the side of an edge will bend it!
We can obviously get too thin and too sharp to be practical. But then there are bragging rights.
1. Heavy pressure of grit on steel can induce fractures that later give way to a chip & those fractures are not always visible.
2. Light pressure obviously induces less friction & heat where heat on a very fine edge can do hidden damage.
3. When you get down below a .001" thick edge, causing the edge to "work back and forth" with each flip of the blade can start to work harden the fine metal edge with unknown effects.
People tend to think that hand held stones can't generate enough heat to cause a problem, but when you are down below .001" thick edges and you push hard, you simply do not know the actual temperature you generate & stresses you induce in the metal on the actual edge and what it does to the microstructure.
I suppose it is possible someone has actually used some super sophisticated instrumentation to find out, but I've not heard of it. It would be fun to know.
I do know that if you want a super reliable "ground" surface on cooled surface grinders you have light pressures by way of very light down feed rates or you literally get burn marks.
I use extremely light forces and consistent angles in making very fine edges.
On extremely thin edges a fingernail's pressure on the side of an edge will bend it!
We can obviously get too thin and too sharp to be practical. But then there are bragging rights.
- Joined
- May 3, 2011
- Messages
- 9,782
- Reaction score
- 4,499
Is it that extreme? It is a perfectly common criterion a blade thin of 0.2mm behind the edge will satisfy, depending on the steel type.
One good thing about waterstones is that under normal sharpening pressure the amount of heat generated is less than just about anything else I know of.
Even using oil stones, or sandpaper I've generated noticable heat trying to get heavy work done. So heat caused by friction with handheld methods is definitely real.
It's also why I'm very much against sharpening using belt grinders. Even with a misting system, I still don't trust that a micron thick sliver of steel isn't getting over heated in a split second, without the person even knowing it happened.
I've blown the temper of knives on a grinder in less than a second doing the primary bevel (after getting down to around .010 behind the edge) by just accidentally apply too much pressure, or moving just a bit too slow.
BoSharpens
Well-Known Member
Using a fingernail sideways pressure on a tip of a real fine edge will bend it when you look at it under a microscope.
Desert Rat
Senior Member
Well we know that a coarse stone can approximate a fine stone with light pressure. Wasn't it the science of sharp guy that honed a straight on a coarse diamond plate and had photos to go with it?
Not sure what your point is?
- Joined
- May 3, 2011
- Messages
- 9,782
- Reaction score
- 4,499
Really no need for a microscope and nothing extreme about it. On any decently thin blade you may see a bulge, as said depending on the steel type.
My point is the big differences we think we notice in the use of these stones is likely something like confirmation bias, possibly they are also reflections of the technique of the person that was sharpening, and about 1000 other variables that can change what the end result we get will turn out like.
To explain my point a bit better. I believe a fine apex, whether the scratch pattern is coarse, or polished, will act very similar considering that the geometry of both are identical. I believe there will be noticable differences even then, but they won't be as dramatic as I think many of us believe. I think that once geometry starts to get changed around a bit, plus the finish of the apex, the differences may become more pronounced.
So can we all agree that anyone who isn't finishing on a venev 400, and stropping with leather with 1 micron diamond spray is wrong? 
That was the point of this thread right?
That was the point of this thread right?
Sure! Just going to toss everything else out like I'm chucking a sickle.So can we all agree that anyone who isn't finishing on a venev 400, and stropping with leather with 1 micron diamond spray is wrong?
That was the point of this thread right?
I dunno, may be its just me; but without any scientific evidence I would pick thousands years of observational knowledge over some person’s opinion on a forum.
The biggest factor affecting this is cutting motion. Even quite small differences in style / technique will have a significant impact on whether someone prefers finer or coarser finishes.
*Everything about cutting anything is about how friction works*. And cutting style has a huge impact.
- Joined
- May 3, 2011
- Messages
- 9,782
- Reaction score
- 4,499
Absolutely. Look at the different geometries, edges and level of refinement push cutting vs. 'guillotine and glide' require.
Desert Rat
Senior Member
Does anyone change the scratch pattern direction while sharpening to suit their cutting style?
I do not. But I always finish with long sweeping edge leading strokes on each stone in the progression. And with extra long sweeping edge leading strokes on the final stone in the progression. So the scratch pattern is always whatever you get from long sweeping strokes. I find this is the best way for me to reduce burr and build a final micro-convexed apex. I am not sure how I would even go about changing the direction of the scratch pattern with my technique.
I asked something similar a while back, I think the general gist of replies was: 'not really worth worrying about'.
https://www.kitchenknifeforums.com/threads/sharpening-strokes.55500/
Desert Rat
Senior Member
I thought maybe some fans of toothy edges might go to the trouble.
I've played with it some, the juice wasn't worth the squeeze for me either but I'm just a home cook so I'm not cutting volume.
- Joined
- May 3, 2011
- Messages
- 9,782
- Reaction score
- 4,499
I only noticed that grooves almost parallel to the edge seem to end in weak points. They occur when thinning at the edge at the long side of the stone. As I use push cutting, forward and pulling slicing, and never completely polish out the scratches of a previous stone, I want the scratch pattern to be perpendicular to the edge. The pattern you get with edge leading stokes over the entire stone surface. I can't tell whether it really matters.
Last edited:
inferno
( ͡° ͜ʖ ͡°) <*))))><
when i read this thread i get the impression that some people think that a 220 edge is somehow just as sharp as a 12k edge. is that so?
i can inform you that this is wrong. its not even on the same planet. never ever gonna happen no matter how long you try. ever.
ever.
i can inform you that this is wrong. its not even on the same planet. never ever gonna happen no matter how long you try. ever.
ever.
Luftmensch
Senior Member
- Joined
- Dec 13, 2017
- Messages
- 2,316
- Reaction score
- 3,185
Similarly.... I tend to do these on each stone before moving to the next - i guess a way of deburring and evening the bevel before the next stone?? I dunno... but it feels right. If the final stone is 3K or above... long sweeping strokes might be all I do! I will switch between edge leading and edge trailing. But the last few strokes are usually edge trailing without slurry or much water... sort of like stropping or a honing rod (this works for me and hard steels).
How do you do sweeping strokes?
I must have got this idea from straight razor sharpening?? I do mine a bit like the rolling X-stroke [1, 2, 3] - except with pretty extreme handle angles (maybe 20-30° from parallel with the top or bottom of the stone). The idea is to keep as much of the edge in contact with the stone as possible - so I use the stone length/diagonal. This is my preference for finishing...
By this stage I am approaching the end of sharpening and checking sharpness with my finger pads or finger nails. If I want to do more work on the heel or tip, I might do that with pressure on one half of the sweep (tip or heel as appropriate). Or... I might use a less extreme handle angle and change the speed of the blade moving across the stone (side to side, not top to bottom). For example, if I wanted to focus on the last half of the edge, I might move from the tip to the middle in the first third of the stone leaving two thirds of the stone (more abrasion) for the middle to the heel. I dont do this often... Usually long even sweeps are fine...
Luftmensch
Senior Member
- Joined
- Dec 13, 2017
- Messages
- 2,316
- Reaction score
- 3,185
I hope not!!!
But.... I suppose new sharpeners might overestimate how much you can correct poor low grit edges with higher grit stones (i.e. progress through the grits too quickly)? In other words, you need to achieve a pretty good 220 edge (but not perfect) before you can get that awesome 12K edge.... Seems obvious I know!!!
Of course... a 220 edge will never be like a 12K edge. But a really, really well done 220 edge might end up being very close to a 1000 edge. After setting the bevel and getting a good apex... we are really just talking about levels of polish. For most kitchen tasks, that is not so necessary. Compared to razors, kitchen knives occupy a relatively low end of the grit spectrum - it is not unreasonable to stop at 1000-3000.
For any combination of steel and bevel geometry increasing the grit (perfectly) will increase the sharpness. But for kitchen knives it is diminishing returns. If your kitchen knife is thin, you might get 70% utility off 400 grit.... 90% utility off 1,000 grit.... 95% utility off 3,000 grit.... 99% utility off 8,000 grit.... 99.5% utility off 12,000 grit....
Depending where your cost-benefit preferences kick in... you might feel that for all practical intents and purposes a 1,000 grit edge is 'just a sharp' as a 12K edge.... (even though they strictly speaking aren't). To me this is some measure of what 'too sharp' is.... wasted effort on stones. But tying this post full circle.... Since kitchen knives only need a progression of 2/3 stones, if you are really, really good with that 1,000 grit stone... it might produce results a lot more like the 3,000 grit stone (eliminate one progression step)!!
One thing is for sure.... my one and only desert island stone would definitely be a low grit stone!!!
