I certainly understand the point (and importance of) a burr when sharpening but then I got to thinking that in some sense the really good sharpeners actually form so tiny a burr that I can't even feel it - given that at my age my finger tips aren't as sensitive as a younger persons. (In fact I sometimes use a piece of cheese cloth to help feel for the (larger) burrs I have to form...)
So what is wrong with the following approach to "burrless" sharpening - other than it would take a bit longer than "feeling for a burr"?
1. Use the magic marker trick to make sure the edge is colored
2. Sharpen until it looks like you have removed the magic marker from the tip of the edge.
3. At that point, whip out a 20X magnifier, check if the magic marker is really really gone.
4. If not, sharpen a bit more and repeat step 3.
My reasoning is that if a 20X magnifying glass shows no more magic marker, haven't you reached the edge automatically and thus have produced at least a microscopic burr?
I tried this on a beater knife and my edge was pretty darn good given the knife's steel.
What am I missing if anything?
Most people do more than "microscopic" damage to their edges. To get a nice, pristine edge, free of fatigued, cracked, deformed metal, you probably need to remove a bit more metal than you are describing. That said, there are plenty of people that do fine with nothing more than frequent touch-ups on 5k stones or something like that.
Wouldn't a 20x magnification show you any reasonable burr?
My understanding of the concept of sharpening is that you need *some* formation of a burr, no matter how small. If you don't have a burr, you haven't reached a *clean* edge as tk59 mentioned. That being said...I would think a burr just visible at 20x would be enough.
I have seen a burr created from one, very light pass on a 10k superstone. Yes it was < 5 microns, but it was there.
That's a good point, I never thought to look for the actual burr, just the removal of the magic marker at the utter edge. Of course, what does a burr look like under 20x, do all burrs look more or less the same at 20x, a kind of bendy rounded metal piece and would the easiest way to see it be too put the microscope on the edge rather than the blade??
Magic marker is Ok for beginning reads on bevels,I would not use it as sharpening tech.Trouble with beginners tips is sometimes they become excess habits.
Burr formation heel to tip is a good teaching,why because your two edges are meeting at a point,then it is a matter of burr removal.Finer stones make smaller burrs & with lite strokes on polishing stones burrs can be taken down to where you can't feel them.That is why touch ups on already sharp knives wt. polish stones can be thought of as burrless sharpening.