Does this happen to anyone else?

[CrimsonTideShooter]

A recurrent trend with me and the edge pro is an unpolished spot near the ricasso of every blade I sharpen. On every single knife there is a little 1/4 inch spot near the ricasso that seems like it doesn't get touched by one of the stones, so the scratch pattern isn't as refined as the rest of the blade. It happens on both sides of the blade, on every single blade I do.

What gives?

 

[powernoodle]

I have noticed this as well. Must be some kind of physics involved that prevents the stone (or polishing tape) from fully contacting that area. Maybe the scale/handle prevents us from getting full contact. Or maybe the tape wears out first on the edge thats making contact with that area.

 

[Obsessed with Edges]

I don't use an edge pro, but I've noticed that the edge near the ricasso is more difficult to sharpen, in general. The blade gets thicker, the closer it gets to the ricasso. So there's a bit of a curve to the bevel as the edge gets thicker in this area. Acts sort of like a recurve, in that the flat sharpening stone won't ride flush against the bevel. More often than not, the stone ends up riding up on the shoulder of the bevel, but not contacting the edge. Would need to go progressively more obtuse with the angle as you approach the ricasso, in order to maintain flush contact in this area.

Here's an interesting & relevant thread, regarding 'thick' edges near the plunge line in the blade grind, just forward of the ricasso:

Why do some makers not sharpen the entire blade?

 

[BladeChemist]

Yup, happens to me a lot as well. Was wondering if the 1/2" stones would work better in this case.

 

[Obsessed with Edges]

Yup, happens to me a lot as well. Was wondering if the 1/2" stones would work better in this case.

I mentioned earlier that I don't have an EdgePro, but I did first notice this problem when using my Lansky guided sharpener a while back. It's hones are about 1/2" wide. A narrower stone will be a little better, obviously, but there'll still be just a little bit of the edge it can't reach in the radiused area near the plunge line. The thought crossed my mind to use the hone made for serrations (the hone has a triangular cross-section), but I haven't tried that yet. I'd think it should work, with a very light and careful touch.

I think the main problem is that the edge is so much thicker near the plunge line. You'd still have to go more obtuse with the angle to maintain the same bevel width, OR keep grinding away with the coarser stones to flatten out the profile near the plunge. But that'll make for a very wide & ugly bevel back there, complete with a very nasty 'gouge' where the edge of the stone cuts into the radiused plunge (I've done this with my Lansky, it's not pretty ).