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sharpening with lower grit stone only

12K views 14 replies 8 participants last post by  scott livesey 
#1 ·
Hi all, another question regarding knife sharpening.

I have 2 shun stones - one is 300/1000 and the other 1000/2000 (I think, might be offer here).

I have just noticed that my knives are sharper when I only use the 300 grit stones to sharpen them. Over the past year, I had been sharpening using 300/1000/2000 and while the knives were sharp they weren't razor sharp as they are now. 

I'm left handed (if that matters) and I think I've got my angle down. I read somewhere online that this was a common problem but I guess I want to know what I'm doing wrong so that the higher grit stones are dulling the knives. Is it too much/little pressure, wrong angle, or what? 

The thing is, even with the 300 grit I can do the fancy stuff like cut a tomato horizontally without holding down the tomato and the paper stuff. I doubt that it is cut an olive in the air sharp but I can feel a significant difference in sharpness - as a test I sharpened one with the higher grit stones too and one without, both are similar knives.
 
#2 · (Edited)
Your lower grit stones will leave a toothier edge which is what you might be feeling. Higher grit honing leaves a finer edge and with VG10 maybe a wire edge that breaks away with use leaving a dull edge. You need to raise a burr then get rid of it which is harder with VG10 than other steels. Do you use the three finger test for edge sharpness?

 
#3 ·
Sharpening is highly personal, but there are a few "rules" that everyone agrees on.

One rule is that the higher the grit you use, the finer the surface on the edge will be, and therefore the more durable your edge will be. 300 grit is great for restoring edges, but it leaves a surface full of deep scratches, and these scratches leave a jagged or "toothy" edge. This can be ideal for many things, especially bread or the like. However, this jagged edge will fatigue and break off very quickly, in other words, will dull more quickly.

Of course you can continue using only 300 grit, and have a toothy edge, no one says you can't, but the only caveat here is thst your knife will "shrink" much quicker, as each sharpening removes a minisule amount of steel. If its an inexpensive knife, no problem, but if its a knife you treasure, you need to be aware.

Hope this helps
 
#5 ·
You haven't given enough info about your sharpening process, sharpness test/standards, and what tactile+audible+visual feedback you're getting at each stage to guess at whether it could be accuracy or angle issues or lack of deburring, etc
Being a lefty doesn't affect sharpening outcomes
 
#6 ·
Your lower grit stones will leave a toothier edge which is what you might be feeling. Higher grit honing leaves a finer edge and with VG10 maybe a wire edge that breaks away with use leaving a dull edge. You need to raise a burr then get rid of it which is harder with VG10 than other steels. Do you use the three finger test for edge sharpness?

I just tried this test on both knives and the lower grit stone seemed more dangerous. This is a pretty scary test if a knife is sharp, I actually did cut a bit of my skin.
Sharpening is highly personal, but there are a few "rules" that everyone agrees on.

One rule is that the higher the grit you use, the finer the surface on the edge will be, and therefore the more durable your edge will be. 300 grit is great for restoring edges, but it leaves a surface full of deep scratches, and these scratches leave a jagged or "toothy" edge. This can be ideal for many things, especially bread or the like. However, this jagged edge will fatigue and break off very quickly, in other words, will dull more quickly.

Of course you can continue using only 300 grit, and have a toothy edge, no one says you can't, but the only caveat here is thst your knife will "shrink" much quicker, as each sharpening removes a minisule amount of steel. If its an inexpensive knife, no problem, but if its a knife you treasure, you need to be aware.

Hope this helps
That makes a lot of sense and is what I'm worried about. Initially I only sharpened with the 1000 stone but it just didn't get the knife as sharp as the 300 grit stone does. I do want to preserve the time I can cut with the knives so I will have to work on my technique I guess.
Also sharpening on a coarse stone removes more metal. I do touch ups on 6000 grit and real sharpening at 1000 grit. 300 is only for repairs and thinning mostly
So you can get the knife super sharp starting with 1000 grit? I will need to work on that. Initially I sharpened starting from the 1000 grit stone because I wanted to reduce the metal I remove from the knife but I couldn't get the knives as sharp as I wanted when starting from 1000 grit.
You haven't given enough info about your sharpening process, sharpness test/standards, and what tactile+audible+visual feedback you're getting at each stage to guess at whether it could be accuracy or angle issues or lack of deburring, etc
Being a lefty doesn't affect sharpening outcomes
I do it fairly slowly, I add pressure, and do it Japanese style where I go back and forth on one part of the blade. Using the various paper and tomato tests. I'm always able to create a wire edge, even with the 1000 grit stones so maybe I'm doing something wrong there as I read that higher grit stones shouldn't create the wire edge. I use the stone to debur (not sure if I'm saying it correctly) and remove the wire edge. I chop a lot of fruit and vegetables these days so I like to have the knife sharp enough to dice onions, tomatoes, etc. with ease.
 
#8 · (Edited)
You should be lightening your pressure with finer grits. Your lowest grit is there for thinning or cutting your crispy edge bevel, all it needs to do. Refine that edge with the following higher grit stones, making sure you're going at the same angle. If you are seeing black slurry on your stone then you are abrading metal, no need to press super hard.

How are you verifying that you're hitting where you mean to be along the edge?

Tests - a coarse grit edge can slice tomatoes and cut paper and shave hair. So can more refined edges. They will feel and act different doing these things. They will also feel very different when using the 3 finger test. You should feel an aggressively toothy sensation on the coarse edge. Whereas with finer and finer edges, you should feel something that is smoother and more keen. Not that it can't also be toothy, but it is unlikely to do so with the same kind of feeling as a 300 grit. With some of those thin, clean, finer edges, even ghosting your fingers along the edge can feel like you are on the verge of slicing into your skin, where you *know* not to press into it with any more pressure- think 'razor' sharp.
I pull cut paper towel to check for burr or otherwise bent/fatigued metal along the edge. Helps with the curve of the blade going towards the tip which is harder to get as consistent and clean sometimes. It will catch or tear at such spots as opposed to continuing a cut smoothly. With both paper and paper towel cutting, finer grit edges tend to cut more quietly and smoothly than coarse edges, will glide through with less friction instead of tearing/ripping.
And finally - try cutting the food you're going to cook and eat and see what's going on there

^ part of above goes to technique, part goes to getting an understanding of what you're getting and then reflecting on what kind of edge you want for your food tasks. Still not sure based on what you've written so far if maybe your perception of sharp is very toothy or jagged based on experiences so far with sharpening

How much time are you spending on each stone?

Try to finish on longitudinal strokes at the same angle as your sharpening when about to finish on a stone and going to the next. Maybe even with a little slightly edge-leading to abrade off fatigued metal, if you are getting wire edges. Make sure you're working the burr to be able to flip very easily before deburring
 
#10 ·
if you have a good knife and cutting board, you should be sharpening with a stone maybe once or twice a year.  you might want to look at  a fine diamond stone(or bench hone) to use for touch ups, 4 or 5 strokes per side.   it may also help to buy a basic carbon steel knife, like an Old Hickory paring knife, to practice on.  
 
#11 ·
You should be lightening your pressure with finer grits. Your lowest grit is there for thinning or cutting your crispy edge bevel, all it needs to do. Refine that edge with the following higher grit stones, making sure you're going at the same angle. If you are seeing black slurry on your stone then you are abrading metal, no need to press super hard.

How are you verifying that you're hitting where you mean to be along the edge?

Tests - a coarse grit edge can slice tomatoes and cut paper and shave hair. So can more refined edges. They will feel and act different doing these things. They will also feel very different when using the 3 finger test. You should feel an aggressively toothy sensation on the coarse edge. Whereas with finer and finer edges, you should feel something that is smoother and more keen. Not that it can't also be toothy, but it is unlikely to do so with the same kind of feeling as a 300 grit. With some of those thin, clean, finer edges, even ghosting your fingers along the edge can feel like you are on the verge of slicing into your skin, where you *know* not to press into it with any more pressure- think 'razor' sharp.
I pull cut paper towel to check for burr or otherwise bent/fatigued metal along the edge. Helps with the curve of the blade going towards the tip which is harder to get as consistent and clean sometimes. It will catch or tear at such spots as opposed to continuing a cut smoothly. With both paper and paper towel cutting, finer grit edges tend to cut more quietly and smoothly than coarse edges, will glide through with less friction instead of tearing/ripping.
And finally - try cutting the food you're going to cook and eat and see what's going on there

^ part of above goes to technique, part goes to getting an understanding of what you're getting and then reflecting on what kind of edge you want for your food tasks. Still not sure based on what you've written so far if maybe your perception of sharp is very toothy or jagged based on experiences so far with sharpening

How much time are you spending on each stone?

Try to finish on longitudinal strokes at the same angle as your sharpening when about to finish on a stone and going to the next. Maybe even with a little slightly edge-leading to abrade off fatigued metal, if you are getting wire edges. Make sure you're working the burr to be able to flip very easily before deburring
Yeah I get the black slurry stuff - actually on all grits by more so on the highest grit stone that I use.

Question - I shave with DE razors so I'm familiar with razor blade sharpness - is this what a super sharp knife is going to feel like?

I chopped tissue paper with the knives and the lower grit stone knife definitely has a louder sound to it.
I would lighten the pressure a bit. I also like to use Sharpies to make sure edges are even. Mark your edge with sharpie then you can see that you edge is even.

scott
if you have a good knife and cutting board, you should be sharpening with a stone maybe once or twice a year. you might want to look at a fine diamond stone(or bench hone) to use for touch ups, 4 or 5 strokes per side. it may also help to buy a basic carbon steel knife, like an Old Hickory paring knife, to practice on.
Thanks Scott. My wife is a hard up and down chopper and it wears out the edge. Normally I sharpen every 4-5 months.
 
#12 ·
I'm guessing your higher grit stones wear more slowly than your lower grit ones, and that you're seeing more of the slurry staying on the stone versus continually get shed off. Otherwise, aim for trying to not create too much on your high grit stones. Again, your low grit stones do the heavy lifting, and the higher grit ones are about cleaning up and refining the edge that's already been established.

Technically, if you sharpened a knife to similar angles (aren't razors roughly 8 degrees per side?) and similar refinement, the edges would feel razor-y. That's definitely on the fragile side for knives that impact cutting boards though. But even at higher angles, you should be able to *lightly* feel with your fingers how the edges feel different with a coarse finish versus a finer one. 

I hope you're at least touching up the knives (not necessarily a full progression sharpening) more often than every 4-5 months. I'm regularly touching up on fine and medium fine stones and generally just restless about keeping more keen edges. As a home user I can be afford to be bit more picky like that :) 
 
#15 ·
Ahahaha, I'm just reminded at this moment of Murry Carter claiming to sharpen razors with nothing but a cinder block and a few strops on a piece cut from his belt and smeared with Cr2O3.
I cringe at the thought of using a razor like that, reinforces why I have not shaved in 15 years.

back to original question, there is nothing wrong with stopping at 300 grit. That is about the grit of a Norton fine Crystolon stone. you have a very "toothy" edge which works very well for slicing fruit and veg and most proteins.
 
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