Why isn't this getting sharp?

[GB]

I use a Lansky Crock Stick sharpener (4 rod version). I just sharpened my Wustoff Santoku the other night. I did about 15-20 passes on the medium and then about the same on the fine. I tested it by slicing through some paper and it went through like butter. The next time I used the knife was on some tomatoes from my garden. It would not cut through the skin except at the very back (heel?) of the knife. Once the skin was pierces it cut great though. Any ideas why this is happening and what I can do (until I talk the wife into letting me buy the Edge Pro Apex system)?

 

[Andy M.]

If it really needed sharpening, 15-20 passes may not have been enough. Did you use a steel after sharpening?

 

[kitchenelf]

Let me say first and foremost I'm no knife expert and not even a knife dummy - I'm below dummy!

Tomatoes are odd little creatures. They succumb to serrated blades the best. The skin may look soft, but, I have learned otherwise. Did you try the knife on anything else GB?

 

[jennyema]

I agree with K-elf.

Even very sharp knives have trouble with tomatoes, in my experience.

Except Chef Tony's knives, that is

 

[GB]

Andy the instructions (if I am remembering correctly) said about 10 passes with each is usually enough.

I did use a steel after sharpening (and before each use anyway) as well.

When these knives were new they would cut through tomato skin like it was not even there so I know they are capable of being that sharp. The heel is still that sharp as that goes through with no resistance at all.

 

[Andy M.]

If this is the first time sharpening the knife, you may have sharpened at a different angle from the original. That may require a longer process to establish the new angle.

I know what you mean about cutting through tomato skin like it wasn't there. I just sharpened my knives and they slide right trough.

 

[Uncle Bob]

GB, I rank in the 'knife dummy' category too! However try your Lansky again, and don't use the steel....See if it changes the results somewhat.

 

[Adillo303]

Hi GB - I'm not an expert here either, I have Henkles, probably similar to your Wustoff's. I have had them 8 or 9 years and never had to "sharpen" them yet. When I bought my house there was a long (about 12") what I always called a steel in the pantry. It is different from other steels in that it is smooth and has no ribs. I always just do 15 strokes on either side when the knife gets dull and I have been OK.

I suspect that the problem is indeed in the angle of the sharpening. I just got a Spyderco sharpmaker. I did my serrated knife on it. I only use that one for bread. It made a big difference.

I offer the same advice as everyone else. Try again being careful of the angle.

AC

 

[GB]

It may be the angle. I try as hard to keep the blade straight, but never know how straight I am keeping it.

 

[CharlieD]

Santoku are the hardest knife for me to sharpen, don't know why. I use wet stone and do not have problem sharpening any knife. Actually tomatoes are the best thing to check the sharpness of your knife. If it is cuting tomato - the knife is sharp.

 

[justplainbill]

I use a Spyderco fine (white) profiler to sharpen our Shun 5.5" santoku only when steeling on a smooth steel (as described by Adillo303, above) doesn't bring the edge back. Sliced tomatoes with the santoku this morning for BLTs. The tomato slices were no more than 1/8" thick.

 

[Chico Buller]

GB, don't fall into the trap that "I only need one more piece of equipment and then I will be a samurai."

As I tell all aspiring sharpeners, get one book on sharpening and some serious articles on metallurgy and HT.

Sooner or later someone is going to ask just who the heck I am to dispense advice, and I'm going to have to produce a knife and a guy they trust.

If this knife is a favorite, write me pm.

 

[buzzard767]

I use a Lansky Crock Stick sharpener (4 rod version). I just sharpened my Wustoff Santoku the other night. I did about 15-20 passes on the medium and then about the same on the fine. I tested it by slicing through some paper and it went through like butter. The next time I used the knife was on some tomatoes from my garden. It would not cut through the skin except at the very back (heel?) of the knife. Once the skin was pierces it cut great though. Any ideas why this is happening and what I can do (until I talk the wife into letting me buy the Edge Pro Apex system)?

You need to continue sharpening until you raise a burr (wire edge). Until you get a burr, the bevels are not meeting. Then remove the burr and proceed to the next finer medium.

A comment: You don't need a serrated blade to cut tomatoes. My knives will practically fall through them under their own weight.

 

[GB]

Buzz, how do I know when I have raised the burr? Is it just a matter of feeling it?

 

[buzzard767]

Buzz, how do I know when I have raised the burr? Is it just a matter of feeling it?

Yes, you will feel it. Instead of alternating sides on the Lansky, sharpen one side of the knife eight or ten strokes, then the other side. Continue to do so until you raise a burr. I've never used a Lansky, but my guess, because of the very small amount of abrasive touching the blade at any given time, the sharpening time will be lengthy. It will go much faster using one inch wide stones like on the EdgePro or three inch wide stones on eight inch free handers.

Removing the burr can in itself be problematic using some steels. There are several methods.
1. continue to sharpen using finer and finer grits making the burr smaller and smaller
2. run the edges lightly through some wood or rubber
3. my new preferred technique - use Hand American hard felt and strop the burr off. I've had great success with the felt.

 

[GB]

Thanks Buzz.

 

[buzzard767]

GB - there is an excellent tutorial that gives all the required information. It's written by Chad Ward, author of An Edge In The Kitchen.

 

[GB]

Thanks Buzz. That will be really helpful. I will read through it tonight.