I did a quick experiment with the .6 Micro-Fine Ceramic stones and edge-leading and edge-trailing sharpening. First I polished the edge .25um with the kangaroo strops. Here is the clean edge:
I didn’t go for perfect, just good enough to have a clean slate.
Next I did 5 very light trailing strokes with the .6um Micro-Fines at 5 degrees wider. Here is the result:
I did another 20 strokes, edge-trailing:
I cleaned up the edge again:
Then did 5 light strokes, edge-leading:
and 20 more edge-leading strokes:
I’m again fascinated by the way metal can be so easily pushed along the surface and piled up on the bevel. I was using whisper-lite pressure.
Hopefully people will jump onto this topic to explore it further and relate anecdotal information about cutting performance with edge-leading and edge-trailing techniques.
This interests me, but I can’t tell what’s going on in the 2nd edge leading photo, other than the metal being pushed you referenced. I don’t see a defined bevel like the edge trailing photo, it looks like a serious burr or that the edge is folded over, and it looks like the pic was taken farther away?
Sorry if its just me… but can you interpret it a bit?
I agree that the second edge-leading image is odd. Clearly a big burr (you know, about 4 microns or something 
) was formed. I’m not sure why since I used very light strokes. I’ll have to wait until tomorrow to repeat it and redo the photography.
[quote quote=“cbwx34” post=4665]This interests me, but I can’t tell what’s going on in the 2nd edge leading photo, other than the metal being pushed you referenced. I don’t see a defined bevel like the edge trailing photo, it looks like a serious burr or that the edge is folded over, and it looks like the pic was taken farther away?
Sorry if its just me… but can you interpret it a bit?[/quote]
very interesting Clay! I have a theory on why the edge bevel is wider on the edge-trailing strokes… I believe it is because you were using more pressure. The reason being is because you are lifting the paddle as you push into the stone, therefore your muscles are keeping the contact and it is harder to regulate the pressure. With the edge-leading passes, you basically just are using the weight of the stone and almost letting it fall. Sound about right? Just a theory 
that’s really weird why the edge looks so un-even in the edge-leading photos… why do you think that is?
[quote quote=“razoredgeknives” post=4670]very interesting Clay! I have a theory on why the edge bevel is wider on the edge-trailing strokes… I believe it is because you were using more pressure. The reason being is because you are lifting the paddle as you push into the stone, therefore your muscles are keeping the contact and it is harder to regulate the pressure. With the edge-leading passes, you basically just are using the weight of the stone and almost letting it fall. Sound about right? Just a theory
that’s really weird why the edge looks so un-even in the edge-leading photos… why do you think that is?[/quote]
Interesting theory - I bet I could put the sharpener on a scale and measure the pressures I’m exerting while sharpening to test it. As for the unevenness, I’m not sure - I’m going to repeat the edge-leading portion today and see if I get the same results.
Clay,
What kind of steel is this blade and what hardness was it tempered to, that you used for this round of tests?
BTW, even though it is not constructive in this case, this sort of deformation or “plastic” flow of the metal is what burnishing is all about (what I have fixed in my head that it is anyway).
This is why I ask about the type of steel and the hardness. It looks more like plastic that has been partially melted than steel
Phil
It’s just an unspecified high carbon steel - I’m using a bunch of utility blades so that I can easily compare apples to apples in different sharpening sessions. I don’t know anything about the hardness. I agree about the burnishing and I find it really fascinating that leather can do it so easily.
[quote quote=“PhilipPasteur” post=4678]Clay,
What kind of steel is this blade and what hardness was it tempered to, that you used for this round of tests?
BTW, even though it is not constructive in this case, this sort of deformation or “plastic” flow of the metal is what burnishing is all about (what I have fixed in my head that it is anyway).
This is why I ask about the type of steel and the hardness. It looks more like plastic that has been partially melted than steel
Phil[/quote]
Well, in the case of these pictures, was that not done with and by the ceramic stones.
You did get rid of it with the srops though…
Phil
Yes, in these pictures the deformation we’re seeing is from the ceramics. I’m about to clean the edge back up and then repeat the edge leading photos.
[quote quote=“PhilipPasteur” post=4682]Well, in the case of these pictures, was that not done with and by the ceramic stones.
You did get rid of it with the srops though…
Phil[/quote]
Here is another shot of the blade as I left it last night after the 20 edge-leading strokes:
I cleaned up the edge again with the .25um kangaroo strops, 20 strokes per side. Again I’m impressed by how well it works. Here is that picture:
I then went on to edge-leading with the .6um Micro-Fine Stones using ultra-light pressure. My technique was to just rest the stone on the blade and let gravity pull it down and using my hand to guide the direction and speed so I wasn’t applying any force in the direction of the blade. Here it is after 5 strokes:
Here it is after 20 strokes with ultralight pressure:
and another 20 strokes with firm pressure:
Haha… I do forget the magnification we’re looking at these sometimes…
I’m looking at them this a.m. on a big screen tv. (god bless modern technology).
Now I’m wondering if it’s possible, to take a shot of the edge looking straight down… to see if that shows any differences between the edge trailing vs. edge leading edges?
Haha… I do forget the magnification we’re looking at these sometimes…
I’m looking at them this a.m. on a big screen tv. (god bless modern technology).
Now I’m wondering if it’s possible, to take a shot of the edge looking straight down… to see if that shows any differences between the edge trailing vs. edge leading edges?[/quote]
Funny you should mention that - I was just working on it this morning and modified my jig to allow the blade to sit up vertically under the scope. It’s hard to find the edge but once I do, I can focus on it fairly well. I did some measurements and got and edge thickness of between .45um and .29um with the Mirco-Fine .6 stones at 28 degrees.
Clay, What angle did you use to clean up the edge with the 'roo and then what angle did you use with the 0.6um micro-fine ceramics?
Thanks,
Ralph
Haha… I do forget the magnification we’re looking at these sometimes…
I’m looking at them this a.m. on a big screen tv. (god bless modern technology).
Now I’m wondering if it’s possible, to take a shot of the edge looking straight down… to see if that shows any differences between the edge trailing vs. edge leading edges?[/quote]
I’ve been waiting for this for a while! Thanks so much Clay! Can’twait to see different results
Funny you should mention that - I was just working on it this morning and modified my jig to allow the blade to sit up vertically under the scope. It’s hard to find the edge but once I do, I can focus on it fairly well. I did some measurements and got and edge thickness of between .45um and .29um with the Mirco-Fine .6 stones at 28 degrees.[/quote]
[quote quote=“wickededge” post=4688]
Funny you should mention that - I was just working on it this morning and modified my jig to allow the blade to sit up vertically under the scope. It’s hard to find the edge but once I do, I can focus on it fairly well. I did some measurements and got and edge thickness of between .45um and .29um with the Mirco-Fine .6 stones at 28 degrees.[/quote]
Cool. These would be interesting to see as well.
It might be worth mentioning… this may be old news to those who have been involved in sharpening for a while, but if you’re new you might not know this… that there is some debate over which method leaves a better edge, trailing or leading. There is differences in the type of burr formed, how the burr is removed and the edge it leaves, whether or not edge leading “smashes” the edge into the abrasive particles preventing it from ever getting sharp, and other factors. Many sharpeners base their whole method on these ideas, and while most seem to make common sense (on either side of the issue), little has been done to actually prove or disprove the “facts”. So, while it’s hard to draw conclusions from just a few photos, over time, this could prove to be very beneficial. B)
Hey Ralph,
I have the sharpener set at 25 degrees for the .6um and 30 for the for the roo strops.
[quote quote=“RalphHoneycutt” post=4689]Clay, What angle did you use to clean up the edge with the 'roo and then what angle did you use with the 0.6um micro-fine ceramics?
Thanks,
Ralph[/quote]
Clay, For some reason I was expecting the opposite. With the roo strops at 30 deg, would it not roll the edge over? … and with the 0.6um at 25 deg, I would have expected it to cut somewhere on the shoulder and not the edge. I think I am missing something.
Thanks,
Ralph
Ralph, you’re right I just goofed up my answer. I stropped with the roo at 25 and used the .6 ceramics at 30! Thanks for catching it.
[quote quote=“RalphHoneycutt” post=4693]Clay, For some reason I was expecting the opposite. With the roo strops at 30 deg, would it not roll the edge over? … and with the 0.6um at 25 deg, I would have expected it to cut somewhere on the shoulder and not the edge. I think I am missing something.
Thanks,
Ralph[/quote]
Bumping this up. Have some questions here (actually searched the forum rather than starting a new thread).
1.) Does anyone have feedback on best performance (sharpness, edge quality) of leading vs. trailing.
2.) Does anyone do both leading and trailing? I was trying 5 each, then finishing 1 each way. After looking at Clay’s photos, would alternating leading/trailing stokes clean up the burr on the bevel and the edge?
3.) Feedback on direction - tip to heel or vice versa? Do you roll the tip less by going tip to heel? (or do I just need more practice?) I did find the mixing tip => heel and heel => tip seems very rough, like going against the grain. Or is this good? Does switching directions get the scratches out or just make more/worse?
