Q&A -- Knife Maintenance and Sharpening

[eGCI Team]

Please post questions relevant to Knife Maintenance and Sharpening here.

[Chad]

First things first. I need to thank slkinsey and the other coordinators. My section turned out to be much larger than I'd intended -- nearly 15,000 words. That, in an of itself, wouldn't be a bad thing, but I was late, late, late with the article. I was still typing madly yesterday morning, awaiting e-mails from Japan, Oregon, Newfoundland and other far-flung spots that would add additional information.

As a consequence the coordinating team had to scramble like mad to get the tutorial formatted and up by this morning. I'm sure there was a lot of coffee involved.

I really appreciate it, folks. Thank you.

Chad

[oraklet]

and i really appreciate your effort - as well as the result. tons of valuable information.

there's one issue you do not touch on: the edge curvature, and the problem of sharpening past the bolster (if you see what i mean). many are the chef's knives that have been "hollowed", and it does not take much change in the curvature to ruin the chopping performance of a chef's knife. in particular this can be a problem with the heavy-bolstered german knives. it can be caused by sharpening with the knife at a 90º angle to the stone (if you're not extremely carefull, that is), or by an irregular stone (and as you mentioned, they do wear) - or by not filing off a bit of the bolster if you wish to put an alternative angle on your knife.

i love the mouse pad trick. i have used sand paper before, but never on a slightly soft surface, and i look forward to trying it. it even has the advantage of being cheap!

and then a question: can one sharpen a boning knife on a stone?

[Chad]

and i really appreciate your effort  - as well as the result. tons of valuable information.

there's one issue you do not touch on: the edge curvature, and the problem of sharpening past the bolster (if you see what i mean). many are the chef's knives that have been "hollowed", and it does not take much change in the curvature to ruin the chopping performance of a chef's knife. in particular this can be a problem with the heavy-bolstered german knives. it can be caused by sharpening with the knife at a 90º angle to the stone (if you're not extremely carefull, that is), or by an irregular stone (and as you mentioned, they do wear) - or by not filing off a bit of the bolster if you wish to put an alternative angle on your knife.

i love the mouse pad trick. i have used sand paper before, but never on a slightly soft surface, and i look forward to trying it. it even has the advantage of being cheap!

and then a question: can one sharpen a boning knife on a stone?

Jeez, I was hoping for a softball first question, and you hit me with the bolster problem? Give a guy a break .

Yes, there are tricky places to take into account when sharpening a chef's knife. There is the belly area where the edge sweeps upward to the tip and the area just in front of the bolster. The belly is more pronounced on German chef's knives than on French chef's knives.

Keeping the angle steady through the belly involves lifting the handle of the knife slightly as you stroke across the stone. It seems counterintuitive, at least to me, but because the knife is narrower at the tip than at the heel, you have to raise the handle a little to compensate. If you're using a v-sharpener (like the Spyderco), you tilt the knife a little downward as you stroke through the belly to the tip.

Forged knives with heavy bolsters will almost always develop a hollow spot in front of the heel. This is a result of the blade shape and the bolster thickness. The thicker metal of the bolster lifts the knife slightly off the stone (or the stone off the knife, depending on your system) so the stone cuts farther back into the edge.

There are two solutions that I know of. If anyone else has a better method, please chime in.

1) File off part of the bolster or have it professionally ground off. Man, it pains me to say that. Especially after spending all that time to convince everyone that professional sharpening isn't necessary. However, most professional sharpeners regularly thin bolsters to fix this very problem. This is an easy job for them.

2) Sharpen down to the heel, but don't take the area just in front of the bolster all the way to a burr. This will prolong the life of that section of the knife. You can leave that area a little coarse (see the "dual ground edge" paragraph in the Sharpening Strategy section for reasons that this might be a good thing) and a little thick. This will keep the hollow from forming for quite a while. The heel of your knife will still be fine for chopping.

Chad

[Chad]

Oh, and can you sharpen a boning knife on a stone? Absolutely. It is a little more difficult than sharpening a non-flexible knife. Boning knives and filet knives require more pressure on the stone. You actually flex the knife into the proper sharpening angle on the stone. This requires a lot of practice on a benchstone. It's a little easier on a v-sharpener because even with the blade flex you can see when the blade is perpendicular to the stone face. On an EdgePro system the blade flex is not an issue because the blade is supported by the blade table. You just sharpen as usual.

Chad

[forever_young_ca]

Wow - Thanks so much Chad!!!!

You have finally motivated me to sharpen my own knives after years of thinking about it. I hate dull knives, but have always had someone else do the sharpening. I plan to print out your tutorial, digest it a second time and decide on a system that will work for me.

Thanks for all your words of widsom and hard work.

[OPJK]

My wooden knife block has vertical slots for knife storage. I was advised when still young (and it has become second nature) to store my knives spine down to avoid dulling the blades when inserting or removing them. I'm not sure it makes much difference in the long run, but thought I'd share.

[marie-louise]

Great job, Chad! I like those guides that hold the knife at an angle; good for those of us with fear-of-sharpening!

I have one or two knives that have slightly bent tips. I suspect they met an avocado pit or other hard object that was more than their match (and despite what he says, I am certain my husband did it.) Is there a way to get them straight again? I don't want to just start whacking at it with a hammer; I have a sneaking suspicion that might break the knife tip.

[Chad]

You have finally motivated me to sharpen my own knives after years of thinking about it.  I hate dull knives, but have always had someone else do the sharpening.  I plan to print out your tutorial, digest it a second time and decide on a system that will work for me. 

Now that is just cool. That's what the whole eGCI is about. Teaching people to do stuff they might have been afraid to try before.

Good luck! Take your time, study the tutorial and don't be afraid to ask questions. Like everything else, sharpening takes practice. Start with a cheap knife just to get the feel for the process. You know, that slicer you bought at the grocery store long, long ago and haven't thrown out yet? Sacrifice that one first .

Chad

[Chad]

I have one or two knives that have slightly bent tips. I suspect they met an avocado pit or other hard object that was more than their match (and despite what he says, I am certain my husband did it.)  Is there a way to get them straight again? I don't want to just start whacking at it with a hammer; I have a sneaking suspicion that might break the knife tip.

Yup, they can be fixed. Bent tips are a problem. As you noted, they can come from hard contact with a pit or cutting board but most often happen when the knife is dropped cavalierly into the sink. Don't ask me how I know this .

I've restored bent tips with a fine ceramic rod used as a file. The Spyderco stones work well for this, but just about any ceramic will do. Lay the knife on the cutting board with the bent tip pointing up. Hold the knife firmly into place and stroke the rod over the bent section to push it back into place and remove any weakened metal. You can also do this in a vise, if you have one. You may have to use a little force, but it's better than the usual solution of regrinding the tip. A severely bent tip may take 10-15 minutes or so to push back into place. Then sharpen as usual.

Chad

[Jeff Campbell]

Great class- thanks.

I have been sharpening knives for years, my technique mostly coming from practice and occasional advice from PCD catalogs, etc. You have given me a lot of great information and techniques to try.

I have accumulated many stones from people who had intended to sharpen their own knives, then eventually abandoned the idea. Is there a good way to assess what theses stones are? What their relative coarsnesss, etc., is?

[Stone]

Is it possible to post photos or perhaps a link to a short video clip showing the actual sharpening motions?

[slkinsey]

Chad, one thing I was curious about... would you consider the "stones" in the Edge Pro set to be "waterstones" per your descriptionm, or do you suggest they be used dry?

[slkinsey]

Is it possible to post photos or perhaps a link to a short video clip showing the actual sharpening motions?

I don't want to put words in Chad's mouth here, but this would be extremely difficult to do as there are a number of different sharpening systems. What you might be able to glean from watching Chad use, say, the Edge Pro system would not really help you if you were using crock sticks or wanted to sharpen freehand, etc.

[Chad]

I'll see if I can find anything suitable. Slkinsey is right, there are so many systems that it would be very impractical if not impossible to demonstrate them all adequately. Razor Edge, EdgePro and Spyderco all produce videos that demonstrate the use of their systems. The Razor Edge video is probably a pretty good guide to sharpening freehand as well.

I do recall seeing some decent diagrams -- maybe a video clip -- that demonstrated freehand technique. I'll see if I can dredge it up. The actual stroke used is significantly less important than following the Burr, Angle, Abrasive, Consistency and Strategy guidelines. It becomes more important as you progress to the finer stones to grind off your burr, but if you go slowly, keep your angle consistent and swipe gently from heel to tip (or tip to heel, however you are comfortable), you should be okay.

Argh, I'm popping in and out because I'm on deadline for a dermatology brochure. Anybody want to know the fascinating science behind laser hair removal?

Chad

[Human Bean]

Chad, one thing I was curious about... would you consider the "stones" in the Edge Pro set to be "waterstones" per your descriptionm, or do you suggest they be used dry?

I use mine dry all the time - seems to work okay, and avoids the abrasive slurry mess. It's something I've always meant to ask Ben Dale (Mr. Edge Pro) about, but haven't ever done.

When I'm done sharpening, I clean the stones with a paste of Bon Ami and water, then rinse and dry them.

I'd also be interested in Chad's opinion when he takes his next break from brochure writing.

[Chad]

Chad, one thing I was curious about... would you consider the "stones" in the Edge Pro set to be "waterstones" per your descriptionm, or do you suggest they be used dry?

I use mine dry all the time - seems to work okay, and avoids the abrasive slurry mess. It's something I've always meant to ask Ben Dale (Mr. Edge Pro) about, but haven't ever done.

When I'm done sharpening, I clean the stones with a paste of Bon Ami and water, then rinse and dry them.

I'd also be interested in Chad's opinion when he takes his next break from brochure writing.

The EdgePro stones are specifically designed to be used wet. They are artificial waterstones, but not Japanese waterstones (natural or reconstituted). I don't think it would hurt them any to use them dry, but they won't cut nearly as well.

Using them wet can be a little messy. If you watch the EdgePro video, Ben Dale uses a squirt bottle to hose down his stones every couple of strokes. He ends up with quite a puddle on his table. My wife would kill me.

I set the EdgePro up on the counter just to the right of the sink -- as close as I can get. That way the stone arm can hang down and over the sink while I wet down the stones. All the slurry and runoff just goes into the sink (where the other stones I'm going to use are soaking).

And instead of using a ketchup-style squirt bottle, I use a heavy duty spray bottle/plant mister set to the tightest stream. Every other pass with the stones (and there are several strokes per pass before you change sides) I use the spray bottle. The high-pressure stream blasts the built-up grit and metal out of the stone without making too much of a mess.

The other thing to watch out for with the EdgePro is the buildup of grit and slurry on the blade table. I don't worry about it too much; my knives are tools. But if you value the aesthetics of your knife or have a particularly nice or collectable knife, you'll want to use painter's tape on the blade. Otherwise it can get a fine pattern of scratches from being dragged across the blade table.

Chad

Edited for grammer

Edited August 14, 2003 by Chad (log)

[slkinsey]

Thanks for the info, Chad. I do have some knives (cast dendridic steel) that I want to keep nice-looking, so I usually just put a strip of clear packing tape on each side of the blade and cut off the excess.

[docsconz]

Any thoughts on ceramic knives? I didn't see them mentioned in either tutorial. How do they compare with metal knives? What about keeping them sharp and sharpening them?

[Chad]

Any thoughts on ceramic knives? I didn't see them mentioned in either tutorial. How do they compare with metal knives? What about keeping them sharp and sharpening them?

I don't have any experience with ceramic knives myself. That's why I hesitated to include them.

But Cliff Stamp has done extensive testing with a Kyocera OK-45 and includes some insights and sharpening information HERE.

Chad

[Chad]

Thanks for the info, Chad.  I do have some knives (cast dendridic steel) that I want to keep nice-looking...

Mmmm, must be David Boye's dendtritic 440c -- very, very nice knives.

Chad

[slkinsey]

Thanks for the info, Chad.  I do have some knives (cast dendridic steel) that I want to keep nice-looking...

Mmmm, must be David Boye's dendtritic 440c -- very, very nice knives.

He cast the blade blanks, but another knifemaker finished them off and did the handles, etc. Super sweet knives. Very toothy, aggressive edge and it takes them forever to go dull. When I became interested in these knives, the maker sent me a sample to play with and suggested I sharpen it up and compare it to my other knives by seeing how many slices I could take from a 1 inch hemp rope until it became too dull to be effective. The dendridic knife held its edge twice as long as the others (the usual Solingen suspects plus a few others) and I eventually gave up before I was able to dull the blade.

[oraklet]

I do recall seeing some decent diagrams -- maybe a video clip -- that demonstrated freehand technique. I'll see if I can dredge it up. The actual stroke used is significantly less important than following the Burr, Angle, Abrasive, Consistency and Strategy guidelines. It becomes more important as you progress to the finer stones to grind off your burr, but if you go slowly, keep your angle consistent and swipe gently from heel to tip (or tip to heel, however you are comfortable), you should be okay.

on another knife thread there was a link to a very good video clip from a high end japanese knife store. wish i could find it...

and thanks for good answers.

[Chad]

on another knife thread there was a link to a very good video clip from a high end japanese knife store. wish i could find it...

and thanks for good answers.

Could be Japanese-Knife. They've got a couple of video clips on sharpening, but the text translation is, well...problematic. Definitely worth taking at look, though. If you want to drop a couple of grand on a Nenox, Masamoto or Misono, this might be your place.

Chad

Edited for spellig

Edited August 13, 2003 by Chad (log)

[snowangel]

Chad, what are your favorite kitchen knives?