Knife sharpening

[barista]

I

On 10/18/2020 at 7:43 AM, paulraphael said:

 

Sharpening a knife with that many curves sounds a bit ... advanced! Have you practiced on a more boring knife? Getting the basic moves and feeling with a regular chef's knife, including the ordinary curve at the tip, is the important part. I think once you're comfortable with that, the adjustments you have to make for an oddball knife will be more intuitive.

 

That said, I don't really understand how you'd sharpen a blade that had a really concave belly on a regular stone.

I do understand the basic, though that doesn't mean I can sharpen my knives with a razor's edge. At best, I'd consider myself average with these basics.

[AlaMoi]

at that price point you have two options:

non-ueber-hyped stones - and manual aka freehand sharpening

or

pull thru carbide fixed angle blade devices.

 

a third option is the 'convex edge' sharpening approach - wet/dry abrasive paper(s) and a mouse pad.

laugh not - it's highly effective!

details here - pix, etc. no longer available

 

you'll find multiple opinions as to the "best" pull through devices. 

however, "the best" are the least worse of the worse devices.

 

inexpensive "all purpose" sharpening stones require experience, and talent, to maintain a consistent angle - but by golly they do work.

 

I went from hand / freehand sharpening to the Edge Pro - and the results were staggeringly superior.

but Edge Pro (and similar) is not in the $50 range.....

 

 

[paulraphael]

Many cooks have learned on something like a King combination stone. You'll probably never need anything better. You may someday want something better. By the time you wear this thing out, you'll have opinions about what you like and don't like. It's under $50.

 

(eG-friendly Amazon.com link)

[weinoo]

And do you have a proper steel/ceramic for honing every time you use your knife?

 

Just as important, in my opinion, as sharpening properly.

[scubadoo97]

Yes I have a ceramic honing “steel” which I use to remove the possible burr from just sharpened knives 

Edited April 25, 2022 by scubadoo97 (log)

[Rickbern]

1 hour ago, scubadoo97 said:

Yes I have a ceramic honing “steel” which I sure to remove the possible burr from just sharpened knives 

Try to use a fine stone to remove the burr. The steel is not as effective 

[scubadoo97]

8 hours ago, Rickbern said:

Try to use a fine stone to remove the burr. The steel is not as effective 

A ceramic rod is not like a grooved steel.   Think of it as a round fine grit ceramic stone

[haresfur]

3 hours ago, scubadoo97 said:

A ceramic rod is not like a grooved steel.   Think of it as a round fine grit ceramic stone

 

I've been using the fine-grit ceramic rods on my SpyderCo sharpener as a hone. I reckon the grit is the same and I'm an incompetent sharpener so a few passes at a consistent angle work well.

[palo]

Steel --> ceramic hone ---> diamond hone

 

I think

 

p

[scubadoo97]

I have become very lax in my knife care.  As long as it can cut a hunk of cheese I’m good 😊 

[Rickbern]

5 hours ago, scubadoo97 said:

A ceramic rod is not like a grooved steel.   Think of it as a round fine grit ceramic stone

The round shape of a steel, no matter the material tends to be less effective than the flat surface of a stone. It only affects a very localized area of the blade  YMMV

[scubadoo97]

51 minutes ago, Rickbern said:

The round shape of a steel, no matter the material tends to be less effective than the flat surface of a stone. It only affects a very localized area of the blade  YMMV

I would agree 

[palo]

I have an oval diamond hone, not sure if oval ceramic hones are available.

 

p

 

[haresfur]

18 hours ago, Rickbern said:

The round shape of a steel, no matter the material tends to be less effective than the flat surface of a stone. It only affects a very localized area of the blade  YMMV

 

Isn't that the idea of honing as opposed to sharpening?

[weinoo]

2 hours ago, haresfur said:

 

Isn't that the idea of honing as opposed to sharpening?

I always thought and learned that honing was to straighten out the edge. Which I do each and every time I use a knife.

[haresfur]

On 4/26/2022 at 11:02 AM, scubadoo97 said:

I have become very lax in my knife care.  As long as it can cut a hunk of cheese I’m good 😊 

 

And you can peel a potato in your hand old-style without slicing your thumb off

[paulraphael]

21 hours ago, haresfur said:

 

Isn't that the idea of honing as opposed to sharpening?

 

This is what we were all taught, but it's not true. In practice, knife edges don't typically roll over in a way that can be straightened. Techniques like stropping and honing just remove damaged metal and create a new bevel (typically a microbevel). 

 

Using a steel does essentially the same thing as using a pretty coarse stone, but without much precision. We usually use a steel at an obtuse angle, so the result is a fairly rough microbevel. If you have a polished smooth steel, you can get results that are more like microbeveling with a finer stone.

 

Here's an interesting 2-part explanation by a guy with an electron microscope. 

 

This kind of edge can be useful. I like it on my big German chef's knife and Forschner utility knife. And I love how quick and easy it is. I think I had to put those knives on the stones once or twice in 15 years ... steeling just does the job. 

 

My thinner bladed Japanese knives don't go anywhere near a steel. There'd no way to use it to get the kind of refined edge I want. But more importantly, those are sharpened to such acute bevel angles that honing would just shred them. You can't put that kind of lateral pressure on an edge when you've got 7° to 10° angles. 

Edited April 27, 2022 by paulraphael (log)

[haresfur]

8 hours ago, paulraphael said:

 

This is what we were all taught, but it's not true. In practice, knife edges don't typically roll over in a way that can be straightened. Techniques like stropping and honing just remove damaged metal and create a new bevel (typically a microbevel). 

 

Using a steel does essentially the same thing as using a pretty coarse stone, but without much precision. We usually use a steel at an obtuse angle, so the result is a fairly rough microbevel. If you have a polished smooth steel, you can get results that are more like microbeveling with a finer stone.

 

Here's an interesting 2-part explanation by a guy with an electron microscope. 

 

This kind of edge can be useful. I like it on my big German chef's knife and Forschner utility knife. And I love how quick and easy it is. I think I had to put those knives on the stones once or twice in 15 years ... steeling just does the job. 

 

My thinner bladed Japanese knives don't go anywhere near a steel. There'd no way to use it to get the kind of refined edge I want. But more importantly, those are sharpened to such acute bevel angles that honing would just shred them. You can't put that kind of lateral pressure on an edge when you've got 7° to 10° angles. 

 

I was just about to post a link to ScienceOfSharp. You are correct from his research that honing creates a micro-bevel rather than just rearranging the metal but I think the point is still that honing does only affect a localized area of the blade. Supports my use of the SpyderCo less acute bevel as a hone. Of course the issue with the SpyderCo for sharpening is that you can't change the angles.

I haven't read up on honing and stropping of straight razors but that might be more akin to what could be done with a low angle single bevel Japanese blade.

[paulraphael]

18 hours ago, haresfur said:

I haven't read up on honing and stropping of straight razors but that might be more akin to what could be done with a low angle single bevel Japanese blade.

 

I bet you won't find anyone using a honing steel on a straight razor (at least not more than once!)

 

But stropping straight razors is pretty standard. Traditionally people would use unloaded leather, which I think mostly served to remove burrs. Now people also use leather as a medium for very fine abrasives, as a final stage of sharpening. You can get powdered diamond or boron that's the equivalent of 20,000 or higher grit stone. This lets you put a very refined and polished edge on a razor, with some ability to deburr, and without as much need for precision as you need on a hard stone.

 

I found this works less well on knives. For years I used a leather strop loaded with 0.5 micron chrome or diamond abrasive for finishing and touching up my gyuto.

 

Then Jon Broida at Japanese Knife Imports convinced me to stop doing this. I went to him looking for a new knife because my Tadatsuna gyuto dulled too quickly. He said the problem wasn't the knife; it was me.  And the OCD sharpening techniques I learned from the internet. He wanted to sell me a new finishing stone, not a new knife—a 6000 grit japanese stone to replace my 10,000 grit one and the strop.

 

And he was right. My edges don't feel as much like a straight razor anymore (because I'm not sharpening them like one) but they perform great and hold on to that performance for days instead of hours. That super-polished straight razor-like edge was amazing for about 20 minutes. But for whatever reason it didn't last. The slightly lower grit edge doesn't push-cut quite as well right off the stones, but actually slices better. It slips through things like the skin of a soft, ripe tomato even after several days of use. 

 

I sold my years-old 10K stone to someone for the same price Jon sold me the new one. Probably to someone who's serious about shaving! The only thing I miss is that the strop was pretty convenient for touch-ups. But using the stone for touch-ups isn't too bad. Jon got me to try microbevels, which are very fast to create and touch up. It's more of a  hassle than honing a European knife, but I only have to do it every couple of weeks, and that's if I'm cooking every day.

[FlashJack]

On 4/28/2022 at 2:40 AM, paulraphael said:

Here's an interesting 2-part explanation by a guy with an electron microscope. 

Thanks Paul for pointing to such an interesting site.

 

Here's my experience:

 

After way too much research and procrastination, a few months ago I bought two Nawina waterstones (800 grit and 3000). They were around $AU150 each. I also bought the Nawina stone holder contraption and the device that provides a platform over a sink.

 

After honing on the stones I use a ceramic rod that was super cheap from IKEA.

 

I also bought a double-sided strop ($100) I load with medium and fine grit paste ($15 each).

 

All up it cost about $600. A lifetime investment.

 

The strop is the killer piece of kit here. An already sharp blade comes off the strop super sharp.

 

I visited a friend on the weekend and sharpened all her knives. She was really happy and I got a lot of satisfaction for making one part of life better.

 

 

[paulraphael]

12 hours ago, FlashJack said:

After honing on the stones I use a ceramic rod that was super cheap from IKEA.

 

I suspect this is helping remove the burrs you raise on the stones. But it's a very aggressive way to do so, and it may be undoing some of your progress. If you stick with the rod, I'd suggest using the lightest possible pressure ... less than the weight of the knife. There are also gentle techniques you can use with the stone itself, or with a piece of hard felt, or even with a wine cork or scrap of wood.

[FlashJack]

On 4/30/2022 at 12:15 AM, paulraphael said:

t may be undoing some of your progress

 A good point Paul.  One balance I think the rod is doing more good than harm but:

 

I do use it lightly. I also do it in a way that keeps my strokes as consistent as possible. For me, it's never seemed natural to go from the top of the rod to the bottom (point coming down towards self). My father, who was challenged in the manual dexterity department, went the other way so that's how I learnt (wrongly I imaging according to popular opinion). After doing a sharpening course a decade or so ago I tried the opposite: the impressively macho chef way. I have a scar on my upper hand behind my thumb as a result. I do recall that not being entirely sober allowed me to laugh that one off.

 

Why I think it's better to sharpen away from self is that when you set the angle to the rod you are doing it at the point of maximum control. The bottom of the rod is closest to the firm grip of the hand and close to the body. Going the other way seems to me an invitation to start the stroke while wavering around at the point of least control.

 

I'm also not interested in going fast. Again, to my mind that's a macho show-off method. I worked with one chef who did a good job with a rod but it involved a blur of dozens of towards-self strokes. It looks impressive -- and that shwoosh-shwoosh sound is awesome -- but I think he just managed to find a way where, on average, the beneficial strokes marginally exceeded those that just did damage.

 

I expect I could lose the rod and get the same result. It's the strop that has greatly improved the finished edge.

 

 

[paulraphael]

For the most control with a rod, plant  the tip vertically on the cutting board with one hand and very gently arc the knife downward on each side. 

 

The tv-chef methods are mostly good for frightening Bugs Bunny when he's tied up in your cauldron.

[rotuts]

re: Ceramic Rods 

 

I have this to add re CR's 

 

I have been using EdgePro set up for some time

 

( I tough up using a DiamondRod , from JewelStick )

 

I ask for their advice  re angle etc when I got my 

 

Watanabe knives .

 

the recommended technique from EP

 

is to more or less very lightly , pull the ceramic rod

 

over the finished edge once .

 

They do not recommend doing this w Japanese

 

or more specifically , Watanabe knives 

 

I don't thick too much about the reason

 

but its want I do , ie w Watanabe , no ceramic rod.

[FlashJack]

7 hours ago, paulraphael said:

plant  the tip vertically on the cutting board

Have tried this from time to time. Just doesn't feel right to me.

 

@rotuts do you strop? Makes all the difference for me.