Since it's a "beloved" knife I'd take it to a professional who can grind down the bolster a bit as needed and reshape the edge to get rid of the scallop. Unless you've really done some damage over the years I can't imagine it not lasting you another 25.

I just looked at my Wusthoff, about 10-12 years old, and I think I can see the scallop that you're talking about but it's extremely minor so far despite my amateurish sharpening skills. I can't imagine it getting so bad that it can't get "rebuilt" even though I also use the fairly aggressive Chef's Choice.

DO NOT use the Chef's Choice on your new Santoku - different angles. And make sure the manual sharpener you bought is red. I've got one of these, too, and it works well for my purposes.

My Chinese cleaver and these two Japanese style knives are the knives I mostly use.

dcarch

I see how that concavity at the bolster can develop. Yes, the bolster can be ground down to eliminate the problem, might take 5 min on a grinding wheel.

One thing you might do is to sharpen less often, by steeling the edge between sharpening.

"Sharpen" means actually grinding away metal from the edge. That can be done with a Chefs Choice, a whetstone, a ceramic rod, a grinding wheel, sandpaper, anything with some texture or roughness.. "Steeling" means realigning and straightening the edge without removing metal. This is done with a smooth round rod. Unfortunately most steels now have some texture which is actually counterproductive. But you can buy a smooth rod pretty cheaply from Victorinox Forschner.

When you use a blade, it becomes misaligned. The edge gets wavy and bent. You cannot see this as it is happening at a microscopic level. Thr result is that the blade becomes "functionally" dull. But this actually happens long before enough metal has worn away to make the edge actually dull at a microscopic level. There is a "microscopically" sharp edge there, but it is just too bent and wavy to cut well.

You can use a steel to re-align the microscopically sharp edge and restore the blade's functional sharpness, without removing metal. Or you can use a sharpener to grind away metal to make a new microscopic edge that, being freshly created, is in alignment and thus functionally sharp.

Doing the former whenever possible, and doing the latter as seldom as possible, will prolong the life of your blade.

I use mostly Victorinox Forschner Fibrox knives. They are made of fairly soft metal, as quality knives go. With daily use, if I don't steel them, I have to sharpen them every month or more. That would really shorten the lives of the knives, as well as consume a lot of time. Instead, I steel the knives before every use - takes 20 seconds - and I only sharpen twice a year.

Here is a simple explanation:

http://cookingfortwo.about.com/od/tipstricksforcooking/a/Knife-sharpening.htm

Here is a knife geek explanation:

http://zknives.com/knives/articles/wssteeling.shtml

The other thing is, don't use glass or stone cutting boards, or cut on plates. Only wood or plastic. Don't put knives in the sink or stuff them in the silverware basket or pile them up in a drawer. Clattering against other stuff will dull the edge in no time, and is also a safety hazard. Don't use a knife to whack bone. That is the job of a cleaver.

Basically, the sharp edge of a quality knife is a delicate thing. To keep doing its job, it has to be treated carefully and maintained with the steel. Otherwise it gets destroyed quickly, and it's back to the grindstone or whatever your sharpening device is, to create a new edge.

Knife talk is worst than talking about politics and religion, it can get really heated. There are so many factors and strong opinions.

John, I hope you don't mine my disagreeing with the Knife Geek you linked.
---------------------------------------------------
"you see a lot of wanna be experts, seasoned cooks, including celebrity chefs, and I don't know who else, rubbing their knives vigorously against the grooved butcher's steel telling you how this sharpens a knife. That is plain wrong and grooved steel is a crime against the edge anyway :)"

I am not a seasoned cook, or a celebrity chef, I am the wanna be expert he is refering to.

" What Steeling Is Not - It definitely is not sharpening. Sharpening, by definition is the process of removal of the metal from the knife edge to make it thinner, i.e. sharper. "

Disagree. Typically, for most knife users, the steel is mostly designed for sharpening. Most cooks use low quality knives with soft metal, and gets dull quickly, the steel is effective in sharpening.

"Why the edges dull - thanks to the human nature significant lateral loads too. It's very hard to keep perfectly straight angle during the cut, the knife wobbles a bit, thus those lateral loads. Vertical pressure is tolerated well, but lateral (i.e. side to side) pressure or loads deform or even break the metal a lot easier."

I cannot understand that at all. I don't think people wobble their knives when cutting, and I cannot see any meat or vegetable that can be hard enough to deform a hardened steel edge. Knives get dull from deformation when cut into hard bones, or hard cutting booards.

"To make the knife sharp again, you have to make the edge straight again, and in more extreme cases, thin it down again. "

To me, a deformed bent edge needs to be removed, not bent back (straighten, re-align) to it's original position. If you have worked with hardened steel you will know that steel cannot be bent too many times. It will lose all its strength or chip once it has been bent. The grinding action of the steel can remove, not restore the bent edge.

"Obviously, chipped edge can not be helped with steeling or stropping, it requires sharpening, which is done with sharpening stone or any abrasive material, but not with a butcher steel."

Not really, the chipping of the knife edge is generally microscopic and can be improved by the abrasive action of the steel.

"if the knife is harder than the steel used for the steeling, then the harder edge will not be affected much. In those cases the ceramic or borosilicate rods should be used. They both have Rockwell hardness above 80s. In fact, it is recommended for ultra hard knives"

Not completely true. While the steel cannot grind a knife that is harder than the steel, it can help remove the already bent edge.

"What is stropping - Well, it serves the same purpose (as steeling), aligning the edge. However, it's done by swiping the edge on the piece of the leather."

I believe he is so wrong I cannot even begin to comment. There is no similarity between steeling and stropping.

"Benefits of steeling and stropping - Steeling(or stropping) is the simplest and the quickest procedure that you can perform to maintain and extend the useful life of your edges, hence the knives themselves."

For general cooks, stropping is not necessary.

"The ideal sequence would be to steel your knives before and after every use. Yes, before and after, and yes, every use."

I would not do anything if your knife is already very sharp.

"For harder Japanese knives, the effects of post steeling aren't as simple compared to softer western knives."

Bad advice. You should never steel a good Japanese knife.

dcarch, a.k.a. knife expert wanna be.

dcarch, I agree with some of your points if we are talking about the usual "steel" sold in most shops, which is a rough grooved rod. Those so-called steels are in fact meant to "sharpen" meaning to remove metal. They do it terribly.

I used my kids' microscope once to examine a kitchen knife edge as I did different things to it. I found out that the grooved rods actually tear the blade's edge into a jagged shape, sort of like a saw. You cannot see this with the naked eye, but you can feel it. Take a knife you don't care much about. It is easier to do this if it is a fairly soft steel, like a Victorinox. Run your finger along the edge, not applying enough pressure to cut yourself, and note how smooth it feels. Then go at it vigorously with a grooved rod type of "steel". Now run your finger along the edge. You will feel a slight roughness. Those are the jaggies torn by the grooved rod.

When you first use that knife, it will cut effectively, as the jagged edge works just like a saw. But the jaggies are soon torn off. Again, you can only see that in the microscope. I think I was using 100X. The blade then ceases to cut well. And you reach for the grooved rod again.

A smooth rod, which is what I consider an actual steel, does not tear jaggies into the edge, at least none visible at 100X, and not as far as my fingertip can feel. But an edge that feels like it to has recently dulled, can be restored to keen again, with the rather gentle use of the smooth rod. Much gentler than the pressure you exert to grind a new edge using a whetstone. If the smooth rod is not grinding away metal - as the microscope seems to show and as the gentleness of our steeling would suggest - how is it making a seemingly dull edge feel sharp again? That is, I believe, the edge re-alignment that I mentioned.

Note that all my experience is with Western knives. Victorinox, Wusthof, Henkels, etc. I have never owned a genuine Japanese knife with the much harder steel that they use. Though I sure hope to, someday. I know it is considered absolutely verboten to use a steel on a Japanese blade. I don't know why, not having personal experience, though I have theories (e.g. ruining the single-bevel geometry of some Japanese blades).

I have sharpened a genuine Japanese knife once, for a friend. She asked me to sharpen a whole bunch of knives. She has dozens of knives, all thrown together in a big drawer, the fine ones with the cheap ones, all as dull as can be. Really sad. I used my waterstone on that knife, got it very sharp though I'm sure not nearly as sharp as it could have been, and wrapped it up in paper before replacing it at the very back of the drawer. It took several hours to sharpen a couple dozen of her 40 or 50 knives. I gave her a Chef's Choice after that.

Stropping - I don't do it, and didn't study it under the microscope. I'd guess it is simply polishing the edge a bit. After you sharpen a blade on even a very fine whetstone, under the microscope you see a pattern of diagonal furrows on the bevel of the edge, that show how you ground the bevel on the stone. Those furrows continue all the way to the edge itself. So the V-shaped cutting edge has a very slight micro-level serration. If you want to polish out that serration, I would suspect stropping could help do that. But I don't mind the micro-serration.

Here is something fun. My son's science class will have an electron microscope for a few months. I have no idea how good it will be, or how a middle school classroom gets loaned such an instrument. The science teacher asked for parent volunteers to be trained on the electron microscope and to then supervise kids. Naturally, I have signed up. He said we could use it on our own too. If it is able to give a useful picture of a knife edge, I'm bringing a whole quiver of knives in different stages of sharpening, steeling, and even stropping.

Found one pic I took. This is after sharpening with a medium stone and then a fine stone (this was back before I got the water stone, my "fine" stone then was like an Arkansas stone).

Pic below is before the sharpening. This knife was a Henckels slicer, the one that SWMBO uses to cut on plates, throw in the sink, stuff in the silverware basket, etc - the sacrificial knife. It had been steeled a lot but by this point the edge was hopelessly dull, and all the re-alignment in the world didn't help. The thin band at the very edge of the edge, is where the (smooth) rid steel had been contacting.

Comparing the after to the before, you can see I re-sharpened it at a more acute angle. It was nice and sharp! That lasted about a week. SWMBO is not kind to knives. She recently used my Chinese "cleaver" to hack chicken bones, broke off big crescent shaped chunks of the edge. I have to completely regrind that blade now.

Good morning.

I usually post over on the Fruit and Orchards board but thought I'd drop in here and see what's what. Found this informative discussion on knives and wanted to chime in a bit.

I have a Wushof bread knife and we love it. When I bought it the salesman told me to use a steel if it ever lost its bite, but so far it hasn't needed any attention.

I also use two Japanese knives from Hida Tool in Berkeley, CA. They are both laminated blades; the cheaper "shark's tooth" appears hand forged and the pricier santoku is machine made. The santoku apparently has the harder steel. Both cut beautifully; the santoku holds an edge longer and is more time-consuming to sharpen. I never use anything except a smallish ceramic (alumina?) stone my brother gave me.

I used those cheaper 12" chef's knifes for years in bakeries, cutting cinnamon rolls and such on a maple bench. They took a lot of abuse but sooner or later they'd get dull and somebody would take a file to them- once in a while a steel.

John, Wusthof's Santoku isn't a real Japanese blade. Those are sharpened at a much different angle than traditional Western knives. Wusthof's version is the same steel as their other knives and sharpened at the same angle. It only has the gratons to distinguish it, but I find them useful, as they prevent certain foods from 'sticking' to the blade.

The old 10" Wusthof I had is long gone. No biggie, I like the feel of the new 8" Wusthof I bought. Just miss that great non-slip handle of the Lamson!

I long ago weeded out my not-often used knives. I use the Kapoosh Knife Block (okay, not great) which fits 6 knives (three large, three small). I'll confess to having a 4" ceramic utility knife which my spouse adores and is the only one babied with its own knife holder, living in the utensil drawer.

Anything else comes in, something has to go out. I have way too much kitchen stuff anyway, LOL!

jkom - the steel might be the same but the angle is not. Unless you ran it through the Chet's Choice, LOL. Or unless they've changed in the 8 years since I got mine. My Wusthoff came with bold warnings only to use sharpeners designed for Japanese blades. And that's why they make a red sharpener for santoku and a black one for western blades.

Nope, my Wusthof Santoku specifically said it could be sharpened on any knife sharpener. Since I live near Hida Tools, I'm well aware of the angle difference on Japanese knives which is why I've not bought any.

John I do use my microscope to examine blades once in a while. With a scanning electron microscope the object will be show completely in focus, there is no optical depth of field like in an optical microscope.

Here are two pictures of a new unused surgical scalpal blade. You can see the edge is not very polished.

dcarch

Nice pictures.

Did you take those with a microscope or with a camera lens? I have somewhere an old bellows attachment for a 35mm camera. Looking at your photos made me realize that the bellows would be useful for these sorts of photos.

I'm interested to use the SEM.

Anyway, that looks like the razor blade edges I've looked at. You can figure out the bevel angle by measuring the edge. The razors I've looked at have a very acute angle, and are single sided, so they are very sharp. That scalpel looks similar. Do you use it for cooking prep?

John I do have a microscope. I am not sure what is the magnification. I have replaced the objective lens and eye piece lenses.

SEM is great, it show details in 3D. But SEM does not show pictures in color, only in B&W.

I use the scalpel blades for many things. Here is a tip, #11 Exacto blades are not cheap. scalpel blades are much cheaper on eBay.

dcarch

dcarch - very cool pics!

jkom - Wusthof has some different lines. The Ikon series for example, does not have the full-length bolster.

Messermeister is another. I believe their Olivia line, in addition to being beautiful, is sharpened to a 15 degree angle.

And Wusthof also offers it's knives with the pEtec edge, which is ground to 14 degrees rather than 20.

Of course the Japanese have different kinds of angles for different knives, but if it matters, there you are.

Here is a link that might be useful: Wusthof Ikon