Knife sharpening 101 ( 101 ways )

iacchus

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I've convexed bush blades before using sandpaper, a belt, and a bit of 2x4.
I've also sharpened a friend's knife on the bottom of his coffee cup (granted, that was just to be an *** about him carrying a dull knife).

Often times we are too precious about these things. As Sal likes to remind us, the edge is a ghost.

The problem I have with the edge pro clones is the stones are so small the just don't cut very fast. They are fine for what they are, but aren't really a proper replacement for bench stones. Better than a coffee cup, though.
 

old4570

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Start with a properly formed edge and edge maintenance becomes much easier .
One should be able to maintain an edge with a leather strop if the edge was ........................

But , if you damage or wear out an edge in a bad way ... Then you need to go back to the beginning and form a good bevel .
Once you have a crisp clean bevel , you can work it to what ever level you want .

As for sand paper ?
I was planning on trying wet N dry paper one day . More like around the 1000 grit range .
Glue it to a nice flat board ...

Butt !

Chinese Diamond plates don't cost that much . If you feel the need to free hand .
 

Monocrom

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I'd just measure a piece of sandpaper, wrap it around that wood block, use some proper adhesive to attach one to the other. Perfect sharpening "stone." Do the same thing with different grits of sandpaper.
 

old4570

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Video 1 is interesting .. But ill stick to my Wet stone grinder !
Savage using a guided system .. Yeah , been doing that for quite some time now ..

Guided system is great if you want a really nice bevel ..
Just one issue with the guided system , it does not FIX a bad factory edge .
What ever FUBAR the factory edge has , the guided system will simply run over it without correcting it .

That's where a wet stone grinder is great ( Tormek ) , it corrects factory (?) FUBAR .
Of course , it all depends on the level of fubar . Some fubar is so bad nothing will fix it . ( A new knife maybe )
 

desert.snake

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I think this will be useful, a man with a very cool electron microscope shows what happens at the very end of the blade

The last few days I have been struggling with sharpening a small knife with an M390. I bought it for $50 about a week ago and it finally got dull from regular use (the worst damage was from sharpening pencils for my friend's kids). I used all the stones I normally use - Norton Crystallon with 2 layers, arkansas/washita, a couple of cheap diamond flakes, a bunch of ancient alumina stones and a piece of degussit. It was all to no avail, the knife becomes a little sharper, but the sharpening is very rough. And after using Japanese synthetic naniwa 1000/3000, it became sharper for a moment and immediately became dull.

After reading the tests in the link, I think I understood that the problem was the destruction of the metal below the point where the burr formed due to too much pressure. In the end, I took a piece of fine india that I had left over from the Randall and very carefully sharpened it with it and it worked, now it is almost as sharp as it came from the factory. I also asked them directly how they sharpen knives in production, to which they replied:
sharpened 120 grit stone grinding wheel and leather grinding wheel cleaning

It seems that factory sharpening, I don't know whether it was done on purpose, or by an experimental method, or just coincidence, is optimal for supersteel, as shown here using the example of s110v
 

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iacchus

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I've never had any issues with sharpening M390/20CV/204P with standard diamond stones, finishing on pasted strop.
Same goes for S90V, 15V, R45 etc.

I sharpen them the same way I would 1095 on an Arkansas stone.
 

desert.snake

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I've never had any issues with sharpening M390/20CV/204P with standard diamond stones, finishing on pasted strop.
Same goes for S90V, 15V, R45 etc.

I sharpen them the same way I would 1095 on an Arkansas stone.

I only have 3 diamond bars, 1 ezelap 21c and 2 pieces from FIT FINCH INDUSTRIAL TOOLS 400 and 600 grit
1719349462053.png

1719349406505.png


So far this is first steel that is difficult to sharpen. There are a couple of knives 440V (S60V) and several S30V, I used to have 20CV from Buck and 10V Spyderco, there were never any problems with them. But the main thing is that it led me to that site, at the same time I found out how to sharpen ceramic knives for my friend
 

iacchus

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I only have 3 diamond bars, 1 ezelap 21c and 2 pieces from FIT FINCH INDUSTRIAL TOOLS 400 and 600 grit
View attachment 64001
View attachment 64000

So far this is first steel that is difficult to sharpen. There are a couple of knives 440V (S60V) and several S30V, I used to have 20CV from Buck and 10V Spyderco, there were never any problems with them. But the main thing is that it led me to that site, at the same time I found out how to sharpen ceramic knives for my friend
20CV is pretty much the same steel as M390. They are analogues, just produced by different companies. If you had no issues sharpening 20CV, then the issues with the M390 blade are likely not steel composition, but blade geometry or heat treat.
 

desert.snake

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20CV is pretty much the same steel as M390. They are analogues, just produced by different companies. If you had no issues sharpening 20CV, then the issues with the M390 blade are likely not steel composition, but blade geometry or heat treat.
We need more tests, I ordered a piece of good diamond 4*1", we'll see. It's a pity we're far away, I'd send it to you to look at
1719351535547.png
 

leukos

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I use a 1" HF belt sander to put a convex edge on all of my tools and cheap knives. Wet/dry sand paper for convexing the super steels. I use a diamond impregnated strop for maintaining the convex edges for the super steels. For the scandi edged knives, I use fine grit DMT 6" plates.
 
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old4570

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Diamond stones sharpen everything !
Ali = around $5 USD each depending on annual sales etc .
I wont be without diamond sharpeners .. Diamond is a must have item !
 

Monocrom

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$50 (even used) for a knife made with M390 as the blade steel.
That sounds WAY too cheap. Guessing there is most likely an issue with the heat treat, and the previous owner knew it.
 

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