Old's guide to sharpening ( The Fundamentals )

Grasshopperglock said:
The direction you move the stone relative to the edge. Pulling the stone only. To pushing it only. Or back and forth. Applying torque as to twist the stone gently. Pressure applied.


Circular motion as to a polish.


The difference between a hard strop and soft. No matter the micron paste.


I disagree with the assessment it's not complicated.
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Pressure and direction does indeed move the scratch pattern on an edge bevel if that is what you are getting at? I don't fully understand why and how but it's true.
 
That's an informative video. I had no idea that there were pull through kitchen sharpeners that can work that well. The appeal here of course is saving time in a commercial setting. It could save a lot of time over manually sharpening knives that are heavily used without the skill/knowledge or time required. This seems especially suited for budget workhorse knives such as the Victorinox knife being used for testing.

I would imagine that the electric sharpener is removing a lot more material a lot more quickly and that is why she claims that it is effective at reprofiling when compared to the manual pull through sharpener.

I was a little disappointed that she did not mention one of the major and most irritating design flaws that I have seen with pull through sharpeners, and that is the offset staggered layout of the "abrasive" as she calls it (the sharpening surface aka stone; whether carbide, ceramic or diamond). It results in having a small section on one side of the heel which remains unsharpened. This starts to build up over time to the the point that a reprofiling becomes necessary to fix it. You can't fix it with the pull through sharpener because that is what is causing the issue in the first place. Maybe she didn't mention it because it is not an issue with the kitchen sharpeners. I haven't ever actually looked at one closely enough to see if they have that same flaw which I have seen on so many other pull through sharpeners.
 
Americas test kitchen does great reviews. That said pull through sharpeners are knife abuse, they work well enough for people with cheap kitchen knives that just want to cut veggies in the kitchen. Which is their target audience for that show.
Posted that to be a little cheeky about old chap's guided system obsession, but looks like he got himself sorted so what a waste. 😢
 
Well I think it's good information. It shows that there are legitimate use cases and good reasons for going with even something that most people on here would frown on. The dreaded and much maligned pull through. People hate them for good reasons but they still seem to have a place if they are properly made.
 
Manual pull through sharpeners work harden the edge. I recently tried to sharpen an older kitchen utility knife that showed signs of being dragged through one of those fly by night, get the edge scraggly enough to cut, call it sharp, devices.


The edge chipped like glass. The knife is now trash.


What a shame too. Vintage USA made Ekco. (*Lights a candle).
 
Guy McVer said:
Well I think it's good information. It shows that there are legitimate use cases and good reasons for going with even something that most people on here would frown on. The dreaded and much maligned pull through. People hate them for good reasons but they still seem to have a place if they are properly made.
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Yep, but it's like posting a spaghetti-o's review on an Italian cooking forum. 😂
 
I just got done putting a dual grit edge on a small Gerber. I'm guessing it's 420hc. 220 on one side, 1000 and polished on the other. Stropped. That no worky for nothing. What a horrible edge. Worked on a cheap 3 pack Oldtimer. Nada on the Gerber.

600/600 and back on the shelf it went.


The mailman needs to show up with my fancy new Poltava stones. Out for delivery.
 
Guy McVer said:
That's an informative video. I had no idea that there were pull through kitchen sharpeners that can work that well. The appeal here of course is saving time in a commercial setting. It could save a lot of time over manually sharpening knives that are heavily used without the skill/knowledge or time required. This seems especially suited for budget workhorse knives such as the Victorinox knife being used for testing.
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Yes, the video by America's Test Kitchen (ATK) is informative, though perhaps somewhat dated, since it was posted 8 years ago. There is another informative video by Burrfection called, "Why I do not use Electric Sharpeners" that was posted 5 years ago. I think both of these videos are pretty accurate.

I have a Chef's Choice model 1520 that is similar to the models in both videos, but not exactly the same. I use it for sharpening inexpensive kitchen knives by Victorinox and various other makers (some of them unidentified). I have some concerns about over-heating the edge. The blade can get slightly warm to the touch, which is the main reason that I do not use an electric Chef's Choice on expensive knives.

The 1520 has 3 diamond grinding disks, 2 coarse and 1 fine. One of the coarse disks (#1) is set at 15 degrees per side. I get 14-15 degrees. The other coarse disk (#2) is set at 20 degrees per side. I get 19-20 degrees. The fine disk (#3) is flexible and is intended for use at both the 15 and 20 degree angles.

I think that both of the videos use a Trizor 15, which also has 3 grinding discs. But the Trizor has 3 different grits, all set a 15 degree angle. The extra grit might make the Trizor better if all you want is a 15 degree angle. But I saw some reviews that said that the 1520 got knives sharper. And I like to have the choice between 15 and 20 degrees.

Each disk has slots on both sides for guiding the blade. This works very well as long as you press the blade lightly against the outer side of either slot. The downside is that you can get some very fine scratches on the blade, from heel to tip. If I were going to try a Chef's Choice on an expensive knife or especially a Damascus blade, I would experiment with Teflon tape first.

Guy McVer said:
I would imagine that the electric sharpener is removing a lot more material a lot more quickly and that is why she claims that it is effective at reprofiling when compared to the manual pull through sharpener.
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Burrfection says that the coarse disk is comparable to his 500 grit whetstones. That sounds about right to me. The grit on the 1520 is coarse enough to sharpen moderately dull knives easily or to do some minor reprofiling, like from 15 to 20 degrees. The grit is not coarse enough for major reprofiling or repairs, as Burrfection demonstrated. The coarse disks do not tear up the knife edge as some bad V-sharpeners do.

Our kitchen knives frequently get minor rolled or mushroomed edges with BESS scores in the 300-400 range. The model 1520 gets rid of those in 1 or 2 passes on each side, on either the #1 (15 degree) disk or the #2 (20 degree) disk, followed by a few passes on the #3 (fine) disk.

A really dull knife, BESS 600-800, might take 15 or 20 passes on each side of a coarse disc to get a good burr, followed by 10 or 20 passes on each side of the fine disk to remove the burr. The grind lines will still be visible on the edge, so I think it would take awfully long to get a mirror edge, if that is even possible--I have never tried. On some low-end steels, the 1520 has trouble getting rid of the burr, in which case I use a strop.


Guy McVer said:
I was a little disappointed that she did not mention one of the major and most irritating design flaws that I have seen with pull through sharpeners, and that is the offset staggered layout of the "abrasive" as she calls it (the sharpening surface aka stone; whether carbide, ceramic or diamond). It results in having a small section on one side of the heel which remains unsharpened. This starts to build up over time to the the point that a reprofiling becomes necessary to fix it. You can't fix it with the pull through sharpener because that is what is causing the issue in the first place. Maybe she didn't mention it because it is not an issue with the kitchen sharpeners. I haven't ever actually looked at one closely enough to see if they have that same flaw which I have seen on so many other pull through sharpeners.
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The electric Chef's Choice sharpeners do not have that staggered design. I do not know about the manual ones.
 
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Grasshopperglock said:
I just got done putting a dual grit edge on a small Gerber. I'm guessing it's 420hc. 220 on one side, 1000 and polished on the other. Stropped. That no worky for nothing. What a horrible edge. Worked on a cheap 3 pack Oldtimer. Nada on the Gerber.

600/600 and back on the shelf it went.


The mailman needs to show up with my fancy new Poltava stones. Out for delivery.
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Trying to get something decent out of a trashfire thread. What is the thought process on a dual grit edge? Im pretty new to sharpening (always paid to have it done before) ive never even thought about doing that.
 
crk1984 said:
Trying to get something decent out of a trashfire thread. What is the thought process on a dual grit edge? Im pretty new to sharpening (always paid to have it done before) ive never even thought about doing that.
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scienceofsharp.com

Dual Grit Sharpening

A few months ago, a video was posted by Pete Colligan on his Cedric & Ada YouTube channel demonstrating the enhancement in edge retention of a knife sharpened by a novel technique, where one si…
scienceofsharp.com scienceofsharp.com
 
crk1984 said:
Trying to get something decent out of a trashfire thread. What is the thought process on a dual grit edge? Im pretty new to sharpening (always paid to have it done before) ive never even thought about doing that.
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The only knife I have that has a dual grit edge, that worked, is on a China made Old Timer. A cheapo knife that comes in the three pack. 240 grit on one side. 1000 grit on the other.

It seems the steal needs to be kinda soft. Soft enough to where you can smear the steel out. Creating the famous dual grit burr.

Every other knife I tried it on. It didn't work for sh*t.


Dual grit really makes a snaggly edge. Micro serrations type deal.


If you want to try it. Don't do it on one of your nice knives. Buy some $5 turd from Wal-Mart and do it on that. Experiment with edge angles. Different grits. Otherwise, it's a waste of time. A standard 600 grit single grind will do everything the dual will but without the drama of trying to figure out how to make it work.
 
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If you want to do it right without gimmicks.

Sharpen the edge to 1000. Feel free to polish it out to 2000. Get it crazy sharp. Something too sharp to shave with.

Then run the 600 grit over it. Lightly as it goes.

The goal is adding, 'teeth' to the fine edge of a 1000.
 
Sharpen the edge to 1000. Feel free to polish it out to 2000. Get it crazy sharp. Something too sharp to shave with. Then run the 600 grit over it. Lightly as it goes.
The goal is adding, 'teeth' to the fine edge of a 1000.
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I need to try this.
Usually I sharpen with #240 or #320 diamond file and then I micro-convex the edge with a strop.

After 600 grit…. do you strop?
 
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