Clarity about apexing

[thmdrnsprtn]

Hi folks,

I’ve just recently gotten a GO with the 200/600 and 800/1000 stones. I have sharpened a few knives with it and am having trouble apexing with my Sebenza now. I understand that new stones can produce suboptimal results, but I’m curious if that’s what is preventing me from apexing here—it’s clear the stone at least on one side is not quite hitting the very edge. I can get a something of a burr from the opposite (right) side, but not the same kind of burr from the left. I’ve spent a good amount of time with the 200 stones flattening out the convex edge and can’t imagine that more time with that stone is what’s needed here…but I could be wrong?

[Marc H]

Welcome to the Wicked Edge Forum thmdrnsprtn.

First I want to say the highly mobile WEGO model although the least expensive and maybe the least accessorized model is as capable as any other model Wicked Edge sharpeners to achieve the same quality sharpening experience, in the hands of an experienced user.  The WEGO model uses the “standard vise” to clamp your knife and lacks micro-angle adjusters.  These features may pose challenges for any user.  Especially for new or less experienced users.

The W.E. GO can be used two ways:

1) set the guide rod angles off the inscribed angle indexing on the blue housing then make the knife edge match that angle setting.  That is what we call profiling the knife edge.  It’s profiling because you are changing the knife’s edge angle profile to match the W.E. settings to an angle of your choosing.

2) matching the existing bevel already established on the knife without changing the bevel angles or profile.  This is what I’m trying to help you to do here.

First some back round: The standard vise with the left vise side fixed stationary and the right vise side floating, attached together by the vise locking screws does introduce a clamped blade lean towards the left side for most every knife you’ll sharpened with it.  This is just a basic characteristics of the standard vise.

If you choose to use the inscribed angle indexing guides, painted on the blue sharpener housing, to set your guide rod angles, and profile the knife edge, the inherent clamping blade lean may throw off the bevels from knife side to side.  This lean may effect your bevel angles enough that you’ll have a different outcome sharpening the left side vs the right side.

For your situation, to match the sharpener to the knives’ actual existing bevel angles you may need to adjust the guide rod angle settings separately, independently on each side of the knife while not making use of the angle inscriptions on the blue sharpener housing.

To help you to see where your sharpening stones are contacting the knives’ blades it’s helpful to apply a sharpie permanent marker over the bevels.  Then as your stone contacts the knife edge you’ll see exactly where the ink is being removed.  This should be helpful to guide you to adjust the guide rod angles to match the knives’ existing bevel angles.  Take your time when trying to match the bevel angles and only move the guide rods with small incremental changes. Then re-tighten the guide rod screws securely so they don’t slip.  When you see you’re removing all the marker ink from the entire bevel height, with your stone work, you have matched the bevel angles with your guide rod positions.  Then with each side’s guide rod set angles now matched to the knives’ actual physical bevel angles you should be able to apex the edge, to draw a burr, to properly sharpen the knives.

Using an optional digital angle device will then allow you to measure and record the matched guide rod settings you found while matching your true bevel angles for the knives.  You can record this sharpening data for your knives in a sharpening log book.  Then you can use these recorded guide rod angles again, in the future, to set the W.E. angles for touchups for those same knives.  (The angle cube can also allow you to determine the clamped blade lean to allow you to compensate for it.)

Many of us use a small bright led flashlight or some magnified visual aid like a lighted jeweler’s loupe to help us see right where the stones are contacting the knife edge and removing steel as we sharpen the knife edge.

I hope I have understood your issue correctly and that this may help.

Marc
(MarcH's Rack-Its)

2 users thanked author for this post.

Dwight Glass, tcmeyer

[tcmeyer]

What Marc said…

Maybe you could add a very simple (and cheap!) 10X jeweler’s loupe to your GO kit.  I’m officially into geezerhood and I’ve noticed that I can no longer see the tiniest line of black marker right at the edge.  A bright light source will help but the loupe will help even more.  There’s a zillion of ’em on Amazon.

2 users thanked author for this post.

Dwight Glass, Marc H

[thmdrnsprtn]

Thank you MarcH and tcmeyer.

I am familiar with sharpie on the edge and have a loupe through which I can see what looks like tiny sharpie line in places at 90x. It’s hard to tell if it’s sharpie or just a different shade of light due to the fact that I’m not completely hitting the edge. I do believe that I have set the angle correctly to match the factory bevel as close as possible (although it seems wildly high; on the arms I have it at ~25 degrees, with the blade resting in the top depth finding notch. Say maybe 23 degrees? I don’t have an angle cube).

So my question is—what is the best way to actually hit that apex? Do I just need to increase the angle a bit more? My understand was that sharpening the edge at a lower angle would eventually remove enough steel to actually apex, but that just doesn’t seem to be the case so far. For instance, if I wanted to reprofile it to 20 degrees, the bottom of the bevel would be hit by the stones first, and then it would slowly progress all the way to the apex. No?

Best image I could get through the loupe.

 

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[Marc H]

You may find it easier to see a red or blue ink sharpie marked bevel.  (I usually recommend the black sharpie because many people already own that sort of marker.)

25º is reasonable for that knife’s edge.  The tendency is for new users to want to reprofile their knives at lower angles. This is simply because with the Wicked Edge they can.  We all seem to believe narrow angles are better! I did the same thing when I first started using my W.E.  I also ruined a lot of knives.  Realize it’s a trade off.  Lower more acute bevels are probably thinner and therefore sharper.  The edge is also thinner and therefore less durable and easier to wear and to fail.  My opinion is if the knife maker had thought the narrower profile was better for this knife and the steel it’s made with, they would have profiled it that way, to start with.  I like to believe the makers had lots of experience and practice while designing and making this knife.  They learned the profile they’re applying is what’s best and practical for most user needs and experiences.

You are correct, like you said, that at a narrower guide rod setting the stones will contact the knife edge lower down the bevel.  So to apex the edge you just have to remove all the steel all the way up to the knife edge.  This is often easier said then done.  Depending on how hard the steel is and how coarse the stone you’re using is, it may take a long time and be a lot of work.  Then when you finally get it done and your knife is reprofiled at that lower angle you picked, you’ve removed and wasted a lot of good new, never used steel, that you can never put back.  If I remember right a Sebenza is not cheap.

From my own learned experiences I now prefer to match factory bevels at first.  This allows me to use the sharpened knife as it was made and intended to be used by the maker.  Then later on after I have first hand user’s experience I may play with the bevel angles.

If you’re having trouble reaching the apex it’s usually because you haven’t matched the bevel angle correctly.  I suggest you try a red or blue sharpie.  With a very fine stone like your 1000 grit, set the guide rod angles wide.  Try 26º to 27º to start.  With this angle your stone should almost lay right over against the apex.  With very very light strokes just remove the ink.  Your not trying to remove any steel.  You might try sliding the stone horizontally side to side across the edge instead of up and down like a sharpening stroke.  You’d expect to see a thin shiny edge line right at the apex.  Reapply the marker. Move the guide rod setting down by 0.25º to 0.50º and retry removing the ink.  Repeat this incrementally as you begin to see the new naked steel mark you’re creating with the stone, as it removes the marker ink.  You should be able to walk the stone down the bevel watching the position change as the bare steel becomes lower on the bevel and wider. Remember to reapply the marker each and every try.

When you begin to see a thin strip of marker left at the apex, above your shinny steel where you’re removing the marker, you know you have gone too low past the bevel angle.  So you know to back up to a wider angle.  Then repeat the process on the other side of the knife.

Realize when you find what you believe to be the matching guide rod setting to the bevel angles that the marker ink may not be removed equally well down the entire length of the knife’s bevel.  You may need to adjust the knife’s position in the vise clamp.  Possible you’ll need to move the knife backward or forward or maybe rotate the handle down, a little.  ( I usually try to center a knife blade to the jaws.) Make these position adjustments minimally and incrementally, applying the marker again as you test for improvements.  By doing this you’ll be finding the “sweet spot”.  This is the best, most efficient clamping position to sharpen this particular knife.  The knife may not be resting on both of the depth key pins when you find the sweet spot.  Sometimes you may not be on either pin.  You learn to work with what you get…As long as the knife clamps tightly and stable, that’s all you need to sharpen it well.

Realize, again, even this may not be absolutely perfect.  The knife as it was made was sharpened with a different type on sharpener with different characteristics. New knives are often sharpened with a belt grinder, by hand.  The edge may be very different from side to side.  More then you’d expect to see. The first time you sharpen any knife with your Wicked Edge it will always do a minimal amount of edge profiling, usually seen towards the heel and the tip. This will make this knife match this knife sharpener.  Each subsequent sharpening. if you position the knife the same and set the angles the same, the Wicked Edge will allow you to be dead-on the existing bevels you applied with this first time sharpening this knife with your Wicked Edge.

If your willing to make the investment and you have a compatible device, some of use a digital USB microscope to help us see our bevels easier.  It’s a great helper.

Hope this gets you closer.  There’s a lot to learn to use the W.E. well.

 

Marc
(MarcH's Rack-Its)

[thmdrnsprtn]

Marc H wrote:

I suggest you try a red or blue sharpie. With a very fine stone like your 1000 grit, set the guide rod angles wide. Try 26º to 27º to start. With this angle your stone should almost lay right over against the apex. With very very light strokes just remove the ink. Your not trying to remove any steel. You might try sliding the stone horizontally side to side across the edge instead of up and down like a sharpening stroke. You’d expect to see a thin shiny edge line right at the apex. Reapply the marker. Move the guide rod setting down by 0.25º to 0.50º and retry removing the ink. Repeat this incrementally as you begin to see the new naked steel mark you’re creating with the stone.

Thanks again, Marc. I’ll try this slow, incremental approach and see where it gets me. I agree about the angle—I don’t need it slicier and don’t need to take it all the way down to 20º. Just needs to be sharp! I don’t even want the mirror edges—just a good working one.

1 user thanked author for this post.

phillyjudge

[Marc H]

I want to be sure this is clear, a 25º bevel on a fairly narrow width/thin bladed knife can appear very small.  A wider angle bevel is shorter appearing than a narrow angle bevel on the same knife blade will appear. This translates to mean the small sized wide bevel make it hard to see where your stones are making contact with the knife edge.  A lighted magnified visual aide is pretty helpful and may almost be necessary to see where your working.

Marc
(MarcH's Rack-Its)

2 users thanked author for this post.

Brewbear, Dwight Glass

[tcmeyer]

I find that it takes very little angular error to make the difference between hitting the apex and not hitting it.  Maybe as little as 0.1 – 0.15 degrees.  Usually, you see the error as the scratch pattern of the current stone not quite reaching the apex (or the shoulder).  Scratch marks from the previous grits will be readily visible, provided that you used alternating directions of strokes with each grit.

I always use strokes down and toward me with the coarse grit on each handle, then down and away from me with the higher grit on the same handle.  This helps me to recognize which scratches are which

If I see that I’m not quite hitting the apex with a given grit, I make a small correction of maybe a half-turn on my micro-adjustment screws.  This seems to work out, as I never seem to need to make more than one correction per blade.

By-the-way, anytime you see an angular error, think hard about why it happened.  As often as not, the cause will be that the micro-adjust (if you have them) has come loose.

It’s also very possible (certainly on systems without micro-adjusts) that the blade has shifted in the vise – rocking from one side to the other.  A worst-case scenario is with a blade that rotates toward the left when you sharpen the right side, and vice-versa.  No, this isn’t a freak happenstance.  It has happened to me on several occasions with blades that are oddly shaped.  The blade simply isn’t held securely in the vise jaws.  Blades with a fuller (also called a blood-groove) right next to the spine are especially problematic.

To test whether your blade is held securely, grab the handle and twist it to one side and the other.  If you see any movement, it’s too much and you should rethink your method of mounting the blade in the vise.

Oh geez… there’s yet another tidbit to share:  Users should be aware that the progression of grits through the line of Wicked Edge diamond sharpening stones have a particular characteristic that helps to keep them closer to the apex with each grit increment.  Since the platens have a given thickness and are plated with diamond particles of given sizes, the height of the diamond particles goes down as the grit value goes up.  Thus, as the measurement from bore center to the surface of the diamonds gets smaller, the handles lean more and more toward the apex.  How much?  Certainly less than 0.1 degrees per grit, but enough to expect that going up in grit won’t increase the angle.  Each user should inspect their handles to see that the platens are installed uniformly.  I’ve had two handles that had a platen attached, but riding up on the plastic border.  I cut the end off and the problem was solved.

2 users thanked author for this post.

phillyjudge, Brewbear

[thmdrnsprtn]

Just a quick update here—I gave this another go tonight and had much better success with the RED sharpie + the loupe. Makes it much easier to see what’s happening at the apex with the different color. Thanks so much for the input tcmeyer and MarcH.

2 users thanked author for this post.

Brewbear, Marc H

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