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Sharpening knives, grinding into or trailing?

Started by Ken S, November 25, 2023, 04:16:34 PM

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Ken S

In the ongoing debate of whether to sharpen knives grinding into or trailing, one question seems to be often overlooked:

Are we grinding with the knife held in a jig or freehand?

While perhaps not the only issue, I believe this is the fundamental issue. Grinding into the edge allows for observing the water flow over the edge. it also allows for heavier grinding pressure and faster grinding times. Grinding away makes freehand grinding possible. Grinding away may also allow for more control due to the slower pace, although a case can be made for the accuracy of using the jig.

Two sub questions should be included with this question: Have we developed the skill to sharpen freehand well? And, how many knives do we sharpen in what time period?

My knife sharpening mentor, who was proficient sharpening in either direction, generally sharpened edge trailing. While he acknowledges that jig sharpening offers the most control, he sharpened at farmers markets for many years with the Saturday morning time constraint of sharpening a hundred knives within the morning. Not having to set up each knife in a jig allowed him to "get up a little speed".

I offer these thoughts as guides and do not recommend carrying them to extremes. Your comments are welcome.

Ken

HaioPaio

Two thoughts
I would not give my best knifes away to get it sharpened freehand, no matter how good this individual may be.
I would love to be proficient enough to do quick and dirty freehandsharpening for my simple knifes. Unfortunately, I'm not good enough.
On the other hand, I have plenty of time.

Ken S

I agree. I would not want my best knives to be freehand sharpened. I would arrange a time and situation where the sharpener would not have the time constraint and be willing to pay a premium fee for the premium service.

That stated, skilled sharpeners, like my mentor, can press the average jig sharpener pretty hard. I would not lump them in with the quick and dirty crowd.

My intention in posting this topic was not to recommend freehand sharpening. I only wanted to offer an explanation for grinding into vs grinding away.

Ken

John Hancock Sr

I have seen woodworkers who can get a board dead flat by hand. I have seen skilled sharpeners who can get a plane iron and plane blade to a precise angle and perfectly flat by eye. Similarly I have seen skilled knife sharpeners who can get a precise angle on a knife by eye. These people are on another level. But that is not me :)

Ken S

John,

Our group seems a mixture. We have members who are on a quest for the perfect edge. We have members who want to turn a reasonable business profit from sharpening. We have members who primarily want to keep their tools and knives working sharp. We have members who, like me, are a mixture of these.

In the past, I recommended learning freehand honing. I have come to believe that efficient use of an FVB has made jig controlled honing a better choice. I can see why Tormek might have favored freehand honing. The plastic knob of the SVM jigs and the plastic horizontal sleeve locking knobs do not clear the support bar legs. An FVB solves this problem. Like you, my freehand skills do not compete with a jig. The jig makes us better sharpeners.

Ken


Digi

I am also in the mixed group :) .
I am still a beginner in the field of sharpening and I sometimes find it a challenge to grind a nice even cutting edge with the jig.
Until now I also do free hand honing, but I ordered the FVB and will experiment with it soon.

tgbto

#6
The way I see it, the Tormek is all about being precise.

If one is trying to achieve the best speed / quality compromise, and is a deft freehand sharpener, a belt grinder with a fine belt on a low speed setting and a separate leather honing setup will yield the best results. Of course heat must be managed buyt that's how most knives are factory sharpened anyway.

Plus it seems to me that edge leading is somewhat faster than edge-trailing...

Ken S

tgbto,

I would classify you in my first mentioned group, "members who are on a quest for a perfect edge". There is absolutely nothing wrong with being in that group. We have all benefitted from the quest. I consider Wootz one of the shining stars of that group. However, even Wootz recognized the value of a not quite quest level, but still very workmanlike, sharpening routine. Here is a link to one of his videos where he demonstrates this method. His sharpened knife has a BESS value of 75. While 75 won't set a quest record, it is certainly quite respectable.

https://youtu.be/UckPmizllk0?si=Z8iaTYrbODIG7yWZ

Just like the stone grader is capable of more than just 220 and 1000 grit, I believe the Tormek is capable of a wider range of precision than just top level to being compared with other sharpening methods.

Ken

AlInAussieLand

Quote from: Ken S on November 27, 2023, 06:47:55 AMJohn,

Our group seems a mixture. We have members who are on a quest for the perfect edge. We have members who want to turn a reasonable business profit from sharpening. We have members who primarily want to keep their tools and knives working sharp. We have members who, like me, are a mixture of these.

In the past, I recommended learning freehand honing. I have come to believe that efficient use of an FVB has made jig controlled honing a better choice. I can see why Tormek might have favored freehand honing. The plastic knob of the SVM jigs and the plastic horizontal sleeve locking knobs do not clear the support bar legs. An FVB solves this problem. Like you, my freehand skills do not compete with a jig. The jig makes us better sharpeners.

Ken


Agree
You can throw me into the "mixed" bag as well. My T8 hasn't arrived yet and I am already looking at another $2K in jigs and other stuff to purchase in the very near future.
I use trailing technique on my Edge Pro (painful to do) on the really hard steel knifes as otherwise they tend to micro chip.
As mainly a knife sharpener "freehand" honing on common knifes is fine. Also sharpening at 240# grid can be an advantage to make knifes "sharp" quickly.
Once you get to the more expensive knifes, a jig even when honing is essential if you want to keep the edge like when it was new.
With a decade worth of sharpening on an "Edge Pro", I learned that depending on the knife's quality and hardness, different techniques are required.
We have a range of good to higher quality knifes and they get treated differently. The "good quality once get the 240# grid with a quick hone for DE-burring treatment. If used as intended by the manufacturer, they will last a long time between sharpening with just a quick touch-up in between.
Some of our high quality once have extremely hard steel and are prone to "micro chip" if touched with a rough stone of 240# or under. They hold their edge for a long time, but are a real pain to sharpen and even worse if they do have some micro chips.

I have got a cheap larger folding knife that I purchased on E-Bay. It was purely purchased as an exercise for the "ultimate" sharpening on an Edge Pro. It took about 10 hours of careful sharpening to get that mirror like edge finishing with a 10K# grid. This knife will truly split hair with ease and you can see your reflection in it. But is it practical ??
NO
So I sharpen knifes in a way to suit their needs and quality, using different techniques.
Can't wait for my T8 to arrive, so that I can widen my tool/utility range that require sharpening/restoring. 

Herman Trivilino

I prefer to sharpen towards the edge. It's faster and the homemade jig I have is easier to use that way. I never could free hand. Strange thing, my grandson has been watching me use my Tormek since he was a little boy. Now an adult, he can sharpen free hand using nothing but a stone and some lubricant.
Origin: Big Bang

John_B

If I recall correctly I thought sharpening away created a more pronounced burr. If so this would make it easier for the less experienced to detect the burr along the entire edge. I think this can be a struggle for those just starting out. I like to develop a consistent small burr that I check with a loupe. Seems to make each knife go a little faster.
Sharpen the knife blade
Hone edge until perfection
Cut with joy and ease

Ken S

Hi, Herman. I am glad you posted. I assume your "homemade jig" is the famous "Herman's Homemade Small Platform" so familiar to the oldtime members of this forum. Sadly, your homemade jig may not be familiar to many of our newer members.

The Tormek SVD-110 is very useful for supporting larger tools. Its Achilles Heel is its width. It is too wide to allow grinding the full length of both bevels of a knife. You corrected this problem by making a narrow platform no wider than the grinding wheel. Your homemade jig is accurate, repeatable, and fast. It is even better because it utilizes A Tormek made platform with the Tormek patented Torlock.
I have made several, which do not work as well as yours. I also have two (one sized for the T4 and a larger one sized for the T7/8) made and given to me by a friend, which work very well. I believe any well equipped knife sharpener who does not have a Herman's Homemade Small Platform has handicapped himself.

Ken

AlInAussieLand

Grinding into using the Jig.
I might be new to Tormek but not new to sharpening (as a User not business).
With the Tormek T8 I can sharpen a knife to hair-shaving sharpness in 10% of the time that I need to use with other devices. And I have done only 5 or 6 knifes, since I just got the T8 last week.
All knifes with Rockwell 56 ~ 60 have taken no more then 3 minutes to sharpen and then about 3 ~ 5 minutes to hone on the leather wheel.

tgbto

If 6 to 8 minutes are only 10% of the time needed on other devices, then either those devices are very ill-suited to knife-sharpening, or maybe you're only using the #6000 grit belt/stone  ;)

Herman Trivilino

Quote from: Ken S on April 15, 2024, 11:39:50 PMHi, Herman. I am glad you posted. I assume your "homemade jig" is the famous "Herman's Homemade Small Platform" so familiar to the oldtime members of this forum. Sadly, your homemade jig may not be familiar to many of our newer members.

Thanks, Ken. Anyone can do a YouTube search using my name and easily find the video I posted many years ago. It shows the prototype, which I have refined a bit, but it gives the basic idea.

The main thing people need to understand is that you have to use the base of the scissors jig, because the tool rest leaves the knife too far away from the grindstone. The scissors jig base is still usable for sharpening scissors, you just have to remove the platform, which is easy to do.
Origin: Big Bang