Edge Leading vs Edge Trailing

[Mark Massie]

Would someone be so kind and define “Edge Leading” and “Edge Trailing”?

Thanks,

Mark

[Jende Industries]

Edge Leading is generally when sharpening with the edge going directly into the abrasive medium as you make a stroke. On the WEPS, an edge leading stroke would be with the paddles starting in a raised position and then pulling downward toward the base, or “into” the edge.

Edge Trailing is the opposite, or when the edge is behind the spine on the abrasive medium. On the WEPS, edge trailing is done when starting the stroke with the paddles closer to the base, and pulling in an upward direction or “away from the edge”.

As for when to use each, you can do edge trailing or leading when using any abrasive medium that is NOT a strop (diamonds, ceramics, Shaptons, Choseras), and you must use edge trailing for anything that is a strop (Balsa, leather, nanocloth).

1 user thanked author for this post.

Haffner

[Mark Massie]

Tom,

Thank you for the clarfication. Care to comment on your experience or pros and cons of each method?

[Jende Industries]

Sure thing! :woohoo:

There are valid arguments surrounding both methods. As usual, choosing one that works better for a specific situation is the best way.

Generally, I find edge leading to be more aggressive, with more “perfection” in terms of the edge of the edge being more clearly defined since it is being abraded into first. With the vertical nature of the WEPS, edge leading has even more “power” since gravity is on its side. However, using too much force/pressure with an edge leading stroke can roll the edge, especially at finer grits – this also applies when setting up the stroke on any grit – you need to be careful not to slam into the edge as you reset for the down stroke.

Edge trailing is, of course, necessary on strops, and tends to round the edge of the edge ever so slightly – more because of the nature of the stropping medium which compresses when against the bevel, but expands again when it goes over the edge of the edge. This is largely why I prefer to use stones as far as I can go before switching to strops, but this slight rounding can also be used to your advantage for a quick touching up. It’s also a reminder that you really don’t need any pressure on the strops. 😉

Edge trailing on non-stropping mediums has a large following, as it seems to “make it easier” for a lot of people. I have my theories about why, but there are two that I subscribe to: The first is that the bulk of the force/pressure is being absorbed by the back of the bevel, which reduces flex at the edge of the edge, and either allows more shallow abrasive penetration at the edge of the edge, and/or it allows the edge of the edge to smoothly run over the bumps on the surface of the abrasive which have been filled in with a slight layer of swarf/debris/paste/whatever.

The second, which is a variation of the first, is that since the back of the bevel is being abraded first, there is some sort of turbulence at the edge of the edge caused by running over the swarf/debris/paste/whatever that cuts just a little deeper into the edge, but without necessarily abrading the entire bevel – much like diamonds can cut deeper, more serrated-like grooves into the edge of the edge, making a knife cut arm hair at the 200 grit level.

In the end, I feel that pressure is the biggest factor determining the success of edge leading vs. edge trailing, with the exception of stropping mediums since edge leading is more likely to roll the edge. More specifically on the WEPS, there is always the argument that if you slip on an edge leading stroke, you will cut your finger off. 👿

FWIW, I prefer edge leading over edge trailing because of the precision aspect.

3 users thanked author for this post.

Haffner, Brewbear, Expidia

[Mark Massie]

Thank you sir. Your insight and willingness to share is much appreciated!

[Ken Buzbee]

Yes, great explanation, Tom!

Two comments:

I only use edge trailing at the early stages of reprofiling. I’ll work one side for 100 strokes down and back, then the other side, then repeat. This is purely for speed to get through the initial stage and I stop doing this as I get near the edge. As easily seen though a loupe.

Secondly, (and you didn’t ask about this 🙂 ) I only do base->tip stokes (after that up and down/back and forth nonesense to get things started:) )

One of the early thoughts I had when I started was being able to see how well I was removing the previous stones scratch marks by going heel->toe on one grit and toe->heel on the next (both edge leading). What I discovered was the two strokes hit the bevel just slightly different from each other. I attributed this to some combination of weight/balance and the way I grip the stones.

So these days I do only edge leading heel->toe stokes and things are much more consistent.

Ken

[cbwx34]

Edge Leading is generally when sharpening with the edge going directly into the abrasive medium as you make a stroke. On the WEPS, an edge leading stroke would be with the paddles starting in a raised position and then pulling downward toward the base, or “into” the edge.

Edge Trailing is the opposite, or when the edge is behind the spine on the abrasive medium. On the WEPS, edge trailing is done when starting the stroke with the paddles closer to the base, and pulling in an upward direction or “away from the edge”.

As for when to use each, you can do edge trailing or leading when using any abrasive medium that is NOT a strop (diamonds, ceramics, Shaptons, Choseras), and you must use edge trailing for anything that is a strop (Balsa, leather, nanocloth).

Thanks… a new Wiki entry 😉

[Geocyclist]

This is what i do. I am not saying it is the best (I get good results), I have not tried every other combination. Please feel free to comment on my post.

My sharpening strategy is based on the following:

I have read (don’t know if it’s 100% true) that Edge Trailing can leave a wire edge, (because the trailing strokes pull material to the edge) that is sharp but falsely sharp as it then folds over and makes the edge dull. I have also read that edge leading is more aggressive, thus can do more damage* to the edge (at least compared to edge trailing) and also can leave buildup on the secondary bevel. * By damage I mean leave more teeth in the edge, the edge will not be as smooth.

I have read that when it comes to heel -> tip or tip -> heel one factor is to just pick one direction is stay with it. I.e. don’t change the direction of the scratches. In my opinion, you can’t discuss edge leading/trailing without bringing this into the conversation. I also have read and tend to agree that aligning the scratches towards the heel (tip to heel stroke with edge trailing for example) puts the teeth in the direction to take advantage of any toothy qualities on pull cuts. I pull cut vs. push cut so I want the teeth in this direction. With a mirror polish edge I don’t know how much this is a factor as there are very small if any teeth in the edge. When I quit after just 1000 diamonds I can definitely tell there is some tooth in the edge.

Strop preservation and dexterity. I am getting better, but in the beginning I picked 1 direction and tried to master it. I chose edge trailing as I have to use it for strops. So I thought I will just learn 1 stroke/1 direction and try to master it.

Therefore, based on the above, I use edge trailing with tip to heel strokes in general for everything, stones + strops.

My general progression is:
Set the bevel:
Mix of Up down scrubbing strokes with full stokes with coarse stone until bevel is set, start to form a burr.

Then for all stones:
Edge trailing, tip to heel as I work 1 grit.
When I am about finished with that grit I do 10 strokes per side edge leading, heel to tip.
This a.) keeps scratches in the same direction, b.) removes the wire edge if it actually exists?
Then I go back to 10 more edge trailing, tip to heel to finish that grit and repeat with the next grit.

Strops:
Only can be edge trailing so I stay in the same direction of tip to heel.

I am curious what other do, especially if anyone get changes directions of the scratches on purpose and gets good results.

[cbwx34]

I have read that when it comes to heel -> tip or tip -> heel one factor is to just pick one direction is stay with it. I.e. don’t change the direction of the scratches. In my opinion, you can’t discuss edge leading/trailing without bringing this into the conversation.
….
I am curious what other do, especially if anyone get changes directions of the scratches on purpose and gets good results.

I was going to ask about this the other day… I change directions several times during sharpening, each step actually, and have never found this to be a problem… in fact, it cleans up the previous grind marks better, or at least a good way to check. I’m curious where this came from?

[Ken Buzbee]

I was going to ask about this the other day… I change directions several times during sharpening, each step actually, and have never found this to be a problem… in fact, it cleans up the previous grind marks better, or at least a good way to check. I’m curious where this came from?

Well, Curtis… Only speaking for me… I go one direction (heel to tip, edge leading) because on several knives I seemed to wander as I got to the ends of the knife. Heel to tip had a slightly higher angle and tip to heel slightly flatter. I only really “noticed” it at the heel and tip.

It seemed like a great idea and I wanted it to work, but, for me, it just didn’t. I’m not saying you can’t, or shouldn’t, just that I can’t.

I can only assume I somehow apply pressure differently between the two directions.

Ken

[FMB1]

“Hold the bevel against the surface of the strop with light pressure and move the blade away from the cutting edge. Turn the blade over and do the same on the other side. The process is the same on any stropping surface, with or without a honing compound.”

The purpose of stropping is to polish the cutting edge, not to sharpen it. Just the same as steeling is not to sharpen, but to straighten a curled edge.

“Contrary to popular belief, a sharpening steel does not sharpen a knife, instead the purpose of a steel is to align the edge of the knife. As a knife is used, the edge will become curled. While you can’t see the curl with the naked eye, a microscope reveals that the edge is askew.”

 

https://www.sharpeningsupplies.com/Understanding-Strops-W111.aspx

• This reply was modified 4 years, 2 months ago by FMB1.
• This reply was modified 4 years, 2 months ago by FMB1.
• This reply was modified 4 years, 2 months ago by FMB1.

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Expidia

[Mr.Wizard]

FMB1 wrote:

“Contrary to popular belief, a sharpening steel does not sharpen a knife, instead the purpose of a steel is to align the edge of the knife. As a knife is used, the edge will become curled. While you can’t see the curl with the naked eye, a microscope reveals that the edge is askew.”

This is incorrect.  I refer you to the work of Todd Simpson at https://scienceofsharp.com/2018/08/22/what-does-steeling-do-part-1/

“The blade was then steeled in the traditional fashion, edge leading at an angle of approximately 30 degrees.  The blade was imaged, confirming that keenness had been restored to the apex and revealing that this was achieved by removal of steel; creating a new micro-bevel.  There is some evidence of softened metal being redistributed; however, a micro-bevel is unquestionably formed through metal removal.”

“In the example below, the Olfa blade was dulled by cutting into an abrasive stone, and then steeled with a smooth, polished steel rod (Victorinox Honing Steel – round smooth polish). Once again, a obvious micro-bevel has been formed through metal removal.”

[Expidia]

Thanks Jende.  Always nice to have vendors chime in to assist the members.  BTW I really like your black and white ceramic hone set.  Great for standing up my rolled edges with a few swipes between sharpening sessions on my WE system.

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[Jeff]

I agree that post by Jende was really informative and glad this got bumped up to the top.  Also almost 7 years old.

[Author]

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