[quote quote=“cbwx34” post=8016]Nice pics!!!
Another factor you might consider is to have someone else do the sharpening… I’m thinking maybe someone who is familiar with the WE, but doesn’t have a lot of experience on it… might show a different perspective. The sharpener is a factor in the equation after all…
He or she also could not tell you which is which ahead of time… help eliminate a potential bias…
Just a thought! :)[/quote]
Are you volunteering? 
No… (I actually was going to put that in the post). I’m thinking someone that may not be biased one way or the other (I think I might be, although I try and keep an open mind)… one reason I thought someone relatively new to sharpening might be a good candidate.
I would think that consistency would be critical in drawing any conclusions. Someone with less experiece may not be able to provide that.
I am curious though. Clay is doing this to answer a question posed. I think he is trying to be unbiased until he has some evidence one way or another. Of course there might possibly be sub-concious biases at work. I just don’t think that this is very likely.
I would guess that a double blind test where the person sharpening did not know the orientation of the blade including placebo blades, or where we would just throw out a random number of blades and photgraph the others.. would be the best way to go… Of course we would need many operators so we could make this statistically sound…:evil:
Not sure how to design that … or if it would be worth the effort.
Phil
[quote quote=“PhilipPasteur” post=8019]…placebo blades…
Phil[/quote]Interesting concept…:lol:
Very good discussion going on.
I think this can easily be 2 separate studies -
is to use an expert operator (Clay) and only one operator to remove the human influence as much as possible to concentrate on leading vs. trailing, as shown by Clay. True any other operator could have different results. This can be repeated by other operators for comparison.
A 2nd study to show the affect the human influence, different operators would need everything else constant but the operator. Same blade, same WE, have the blade set in the vice by the administrator each time. I think (haven’t tested) the #1 human influence is pressure that creates different results. Also speed, length of stroke etc.
In the end it I think it is hard to remove the human element from sharpening, at least for a controlled experiment, without being able to measure and control critical variables such as pressure.
I searched the web on this one a while and found more questions than answers. I did like this post here.
Key points I picked up were:
[ul]
[li]Some people talk about the edge getting duller as they progress through stones[/li]
[li]May be due to “snow plow” effect of the blade rolling on edge leading instead of cutting the steel[/li]
[li]Edge trailing will polish more[/li]
[/ul]
Do both leading and trailing on coarse stones
Finish on fine stones with trailing only
Strop
I am now wondering if this is what Clay’s photo of edge leading is showing, a rolled or deformed edge? I am very curious to see how this knife does in the same sharpness tests.
Something we need to add in is BassLakeDan’s point sharpness tester. The data from that test alone would be really useful to determine at least one point of efficacy of varying techniques. Has anyone built one yet?
Ok, I have been reading this ongoing, and it’s fascinating.
But please forgive my ignorance…I thought I knew what you were talking about, until I didn’t.
Can someone please define ‘leading vs trailing’? I thought you were talking about going tip to heel or vice versa. Call me a noob, but this one has confused me.
[quote quote=“FredHermann” post=8073]Ok, I have been reading this ongoing, and it’s fascinating.
But please forgive my ignorance…I thought I knew what you were talking about, until I didn’t.
Can someone please define ‘leading vs trailing’? I thought you were talking about going tip to heel or vice versa. Call me a noob, but this one has confused me.[/quote]
Think of edge leading as if you were trying to cut the medium. Edge facing the direction of movement. Edge trailing is the opposite where you drag the blade across with the ‘edge trailing’.
Hope that helps you. It’s actually a controversial topic in the sharpening community… haha;)
An edited post (mine) from my thread (not here) 10/31/2012 …
This 2 images are what I’ve envisioned a few months back. These are (~ 30% resemblance) my mental images that I stared at for countless hours and they still make sense today as the day I came up with them. Please hold-on to other variables (abrasive shape, steel composition/ht, etc) while we look at this simplified models.
V t/l is the velocity - blade or abrasive movement.
P is the blade normal force against the abrasive.
Av (Abrading Vector) is the cutting vector imparts torque on the blade. The edge will deflect/bend when the torque exceed the tensile strength at given edge thickness.
Burr-nana peel.
Apex deflect or roll but no burrnana.
These models should provide reasonable answer to alot of nagging questions.
ex1: ‘how come the burr seem long but blade height wasn’t shorten by the same amount?’
burr-nana peel around the apex, so blade height loss usually much less than burr length.
ex2: ‘raised burr 2 sides, deburred but didn’t apexed?’
Too much press, burr-nana peel around a blunted apex. Once burr removed, you end up with a blunted/un-apexed edge.
ex3: lip
Whenever Av too large for the apex area, abraded area will occur below the apex.
Nice illustrations…and I have seen the post where you put it up originally. I still don’t follow it or see how you get your three examples. Maybe you can explain.
In any case, when using the WEPS… or even bench stones, I can’t say that I have seen anything… via edge perfomance nor micrographs to allow me to buy into your theory. I do have several bench stones that I can’t use edge leading, but obviously (to me) do produce significant edge refinement when used edge trailing. No “burnana-peel” or false burrs, that I can detect.
Would like to hear more explanation from you… and more hard evidence with Clay’s tests and photos.
Phil
[quote quote=“PhilipPasteur” post=8129]Nice illustrations…and I have seen the post where you put it up originally. I still don’t follow it or see how you get your three examples. Maybe you can explain.
In any case, when using the WEPS… or even bench stones, I can’t say that I have seen anything… via edge perfomance nor micrographs to allow me to buy into your theory. I do have several bench stones that I can’t use edge leading, but obviously (to me) do produce significant edge refinement when used edge trailing. No “burnana-peel” or false burrs, that I can detect.
Would like to hear more explanation from you… and more hard evidence with Clay’s tests and photos.
Phil[/quote]
Envision an edge cross section (a geometrical 2D triangle, where the area is the blade edge):
Burr form at the bend because the abrasive no longer able to penetrate the upward bent surface. If the sharpen stroke is super slow, so Av is mostly normal/perpendicular pressure to the surface. Then in this case, neither Trailing or Leading can create an apex thinner than 5 molecules thick.
Using this envisioned model to add more details to my Prev post:
ex1: ‘how come the burr seem long but blade height wasn’t shorten by the same amount?’
If start out with a flat-top edge, as abrading material reach the flat edge and thickness is less than the tensile/bend strength, these material will hinge/flop over the flat-top. Now you’ve the burr but far from apexed. Many beginers ran into this by feel the burr alone without looking at the edge reflection.
ex2: ‘raised burr 2 sides, deburred but didn’t apexed?’
ex1 applied to both side of bevel face
ex3: lip
Whenever Av N exceed tensile strength in area below apex, thus kept abrade more and more below where sufficient thickness to support abrasion. This problems are more applicable for advanced sharpeners.
Again, my posts don’t addressed the complete complexity picture of steel+abrasive+interaction characteristics. I merely focused simplistic edge lead or trail abrading interaction.
During some reading (HERE on pg 18 specifically) I found some interesting documentations regarding edge leading vs edge trailing sharpening… In this paper Dr. Verhoeven is comparing razor blades (specifically on pg. 18 I think it is a straight razor):
“All of the sharpening done on the waterstones moved the blade along the stone in
the direction into the blade edge [edge leading] causing the abrasive debris to move away from the edge.
It was theorized that moving in this direction would reduce the bur size at the edge by
preventing the debris from being deposited along the edge. To see if this theory was
supported by evidence an experiment was done on the 6000 grit waterstone where the 10
4-stroke cycles were all done with the blade edge moving away-from [edge trailing] rather than into the
stone surface. The results are shown in Fig. 27. Comparing Figs 25 and 27 one sees that
moving the blade away-from the edge, as in Fig. 27, does seem to produce a significantly
larger bur than moving it into the edge, as in Fig. 25. The larger bur is also accompanied
by an increase in edge roughness, as shown in the face views.”
you will have to view the paper so you can reference the photographs… thought this was interesting.
[quote quote=“razoredgeknives” post=18454]During some reading …
you will have to view the paper so you can reference the photographs… thought this was interesting.[/quote]
Thanks for posting this. I’ll finish reading it later today…
Is this what you read for leisure & entertainment? I do.
After watching The Woodrights Shop’s explanation & demonstration of cross-cut and rip saws I’ve been re-reading the first two chapters of Leonard Lee’s “The Complete Guide To Sharpening”.
They are “The Meaning of Sharpness” and “The Physics of Cutting Wood Fibers”
“Unless you are living in a remote area, sharpening your own knives really does not make sense. The time consumed is usually out of all proportion to the money saved, and the end result is usually of lower quality than that you could expect from even a run-of-the-mill sharpening service. This is truly one area where equipment overwhelms technique by a substantial margin. If you do not have an excellent system for holding a blade straight and rigid, you will be in trouble from the opening gun.”
Thanks for posting…
[quote quote=“GibCurry” post=18488][quote quote=“razoredgeknives” post=18454]During some reading …
you will have to view the paper so you can reference the photographs… thought this was interesting.[/quote]
Thanks for posting this. I’ll finish reading it later today…
Is this what you read for leisure & entertainment? I do.
After watching The Woodrights Shop’s explanation & demonstration of cross-cut and rip saws I’ve been re-reading the first two chapters of Leonard Lee’s “The Complete Guide To Sharpening”.
They are “The Meaning of Sharpness” and “The Physics of Cutting Wood Fibers”
“Unless you are living in a remote area, sharpening your own knives really does not make sense. The time consumed is usually out of all proportion to the money saved, and the end result is usually of lower quality than that you could expect from even a run-of-the-mill sharpening service. This is truly one area where equipment overwhelms technique by a substantial margin. If you do not have an excellent system for holding a blade straight and rigid, you will be in trouble from the opening gun.”
Thanks for posting…[/quote]
Yeah I do read this type of thing because I enjoy it! Lol
The only thing I take issue with what you quoted from the show is that I think sharpening is easy with a little practice and can be done with minimal tools… Look up cliff stamp sharpening a knife on a brick to newsprint slicing sharpness
[quote quote=“razoredgeknives” post=18489]
Yeah I do read this type of thing because I enjoy it! Lol
The only thing I take issue with what you quoted from the show is that I think sharpening is easy with a little practice and can be done with minimal tools… Look up cliff stamp sharpening a knife on a brick to newsprint slicing sharpness[/quote]
I concur. But, the quote about holding the blade rigid is one of the clues that led me to the Wicked Edge.
I don’t necessarily agree with all Mr. Lee’s conclusions or opinions but his “science” is interesting and entertaining to me.
“[i]Sharpness for a cutting tool could be defined as two surfaces meeting at a line of zero width. That might be fine theory but could result in bad practice. To be effective, a cutting tool not only has to have an edge of zero width, but the angle at which the two surfaces meet must accommodate the intended use of the tool and the material from which the tool is made.”
“Unlike wood, meat and soft vegetables have little rigidity to their structure. They are about 95% water held together with films and filaments of varying strengths. To cut them, you need an edge that will rend their fabric at very low applied pressure.”
“The skin of a tomato is sufficiently tough that it will maintain its integrity in the face of pressure from a smooth knife edge. Of course, you can only apply relatively light pressure, otherwise you tend to squash the entire tomato. You will find that a less finely finished edge, one that has many fine serrations in it from a medium-grit abrasive (400x to 1200x) will cut into the tomato much more easily because it is better designed to tear apart a film and sever fibers. Although the desirable amount of serration varies, you want a bit of tooth on any blade used for soft vegetables, meats and bread.[/i]”
Nothing new. Still interesting. (To me)…