# Over sharpen?



## HPoirot (Apr 10, 2015)

Is it possible to over sharpen a knife? 

I'm asking because i'm eager to learn how to sharpen knives with stones. But the problem is i don't use my knives often enough! I probably use it once every couple of months. 

So, i can just sharpen it anyway? Though i doubt i can gauge how effective i am that way.

I should add that i'm talking about V10s petty and gyuto, and a Blue #1 yanagiba, all used <10 times. 

Would sharpening or touching it up after use be excessive?


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## chinacats (Apr 10, 2015)

I would recommend buying a few bags of lemons and this should sufficiently destroy an edge...if not, there is always glass.


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## shownomarci (Apr 10, 2015)

I don't think anything like "oversharpening" exist on this forum. 
You can always cut up some stuff just to have some use for your knives. 
Cut some fruit or veg to nibble or even better... Start cooking!


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## chefcomesback (Apr 10, 2015)

shownomarci said:


> I don't think anything like "oversharpening" exist on this forum.
> You can always cut up some stuff just to have some use for your knives.
> Cut some fruit or veg to nibble or even better... Start cooking!



Yes it exists ,lot more than you think


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## Benuser (Apr 10, 2015)

Sure, you do wear out your knife. Better get a cheap basic carbon blade for practice. In Europe I would suggest a simple Herder. I believe in the US you still have Old Hickory, don't you?


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## jared08 (Apr 10, 2015)

I picked up 4 old hickory knives for 20$ on the bay


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## ThEoRy (Apr 10, 2015)

The more you sharpen your knife, the more rapidly you erode it's useful life.


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## Lizzardborn (Apr 10, 2015)

ThEoRy said:


> The more you sharpen your knife, the more rapidly you erode it's useful life.



Which gives you a good reason to buy new ones. And more expensive.

But if you are not really good sharpener I think that you can oversharpen a knife. The edge is a delicate thing and you do put some lateral stress on it.


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## mhpr262 (Apr 10, 2015)

Just buy some cheap stainless and practice away. Lots of people say "oh it won't give you the feedback like carbon bla bla bla .." but at the end of the day sharpening is about being able to hold a consistent angle, adapting angle to profile, knowing how to get and remove a burr and testing for sharpness. No reason that can't be learned with a ss beater.


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## simar (Apr 11, 2015)

if you are asking is it possible to over sharpen a knife then yes. You can prematurely remove metal from the blade reducing its life. This isn't the end of the world, but its your money, do as you desire.

You can also over sharpen to the point where you knock off the teeth you need for the knife to perform its tasks.


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## HPoirot (Apr 11, 2015)

Does this mean i can also practice on cheap stamped knives? Or is there a minimum standard i should be shooting for?


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## Pensacola Tiger (Apr 11, 2015)

Most people learn better with immediate feedback, so that they can modify what they are doing to get the best results. Cheap stainless and stamped knives aren't conducive to quick feedback, at least the way a carbon blade can be, and that is why beginners are advised not to learn freehand sharpening with these knives. To give you an idea of what I am talking about, let me go back a few years to when I was just starting to sharpen freehand, and offered to put good edges on a friend's kitchen knives. I forget the brand name, but they were cheap stainless, and it took me a ridiculously long time to even raise a burr. I eventually got them sharper than then when I started, but not to the standard I was trying to reach. Had I been trying to learn on these knives, it would have been extremely frustrating, not to mention confusing, as I would have been left wondering what I was doing wrong, when it was the knife, not my technique.

By a cheap Tojiro shirogami petty to learn on if you are leery of learning on your good knives.

Rick


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## psfred (Apr 11, 2015)

Two ways to look at "oversharpening": sharpening when the knife doesn't need it and sharpening it beyond the capability of the steel.

I wouldn't sharpen a home knife all that much, occasional use isn't going to dull it unless it's knocking around in a drawer with the edge unprotected (which I am sure you are not doing!). For steel of the order of VG-10 or Hitachi Blue, touch-ups are really only necessary when the edge loses it's "magical" sharpness, which it not going to be every use.

Sharpening these knives all the time without allowing them to dull is the first sort of over-sharpening in my book.

Lesser stainless knives with soft steel should not be sharpened up through very high grit stones because they have fairly large chromium carbides embedded in a fairly soft matrix, and high grit stones will pull the carbides out of the edge. These carbides give softer stainless great abrasion resistance and allow you to reset the edge with a fairly soft knife steel since base steel isn't all that hard, it bends rather than breaks in use. If you yank all the carbide near the edge out, you are left with soft steel that will take an amazingly sharp edge for one cut, then become quite dull. Think Henkles, Wustoff, and Victorinox "traditional" chef's knives. 

Sharpening these knives up to 10,000 grit and stropping on diamond is the other sort of over-sharpening, going beyond the capability of the steel.

While wearing out a knife can in fact be done, it's fairly difficult in the home kitchen unless you are in the habit of excessive sharpening events or serious over-use of a steel on softer knives. The amount of steel you remove is small at each sharpening as a general rule, and if you only sharpen when the knives actually need it, it will take a long, long time to do much damage. I sharpen even my mediocre Chicago Cutlery knives every six months or so, and that may be excessive once I get them in better shape -- the edges were pretty flat when I got them. I've sharpened my Tojiro DP exactly once in nine months, and probably won't sharpen again for quite a while, it's still cutting very nicely. 

Professional use is quite a different animal, and even top quality knives may need sharpening weekly (or more often depending on what the chef wants and the knife), so it's possible over a few years to remove enough metal to alter the profile enough to change the knife. Eventually it will become difficult or impossible to maintain the basic geometry as the edge moves up into the body of the knife, and after a certain point it makes more sense to replace rather than re-grind the knife, and it may in fact be impossible to restore the original profile. This will happen faster with softer carbon steel than with high hardness alloys, but all knives will eventually become useless from sharpening.

My brother inherited his father in laws packing house knives. Many of them have been sharpened so much the profile is altered, and they all need some thinnning to work nicely. Old style carbon steel -- as the original owner said, you have to have knives that stay sharp a long time and are easy to sharpen, or you can't keep up with the work. He could de-bone a raw ham in 30 sec or less, I think, since he did it for a couple decades all day long. Wore out quite a few knives in that time, too.

One other note: use of those horrible "pull through" sharpeners will greatly reduce the life of a knife, so will powered sharpening tools. Along with removing way too much metal way too fast, they make the knife thick behind the edge quickly and offer no means of correcting this, so even if sharp (and they won't be, really) they will wedge terribly.

Peter


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