Here are some pics to try to clear things up a bit.
On the left is a standard HI blade ground on a grinding wheel - which gives it a slight hollow grind (the horizontal lines are where the bevel starts). I figured a 10" radius and a bevel about 5/8" long. (these are AutoCAD drawings, btw, so I
have to make it accurate....
)
In the middle is a properly reground convex edge. Just slightly more convex than a flat grind.
On the right is an overlay of the two grinds.
Here's a closeup:
I've filled in the area that has to be removed.
You could easily remove these parts with a file by clamping the blade to a 2x4 and drawfiling. For the edge part, just hang the edge over the board a little bit.
The important thing would be to make consistent, steady strokes. Take plenty of time and don't rush it.
Once you have turned it into 3 bevels, then you can start rounding those corners down, etc. until you have your convex edge.
To make it smooth like a grinder does, just get a sanding block, glue a thin piece of soft leather or foam to it and use 120 grit sandpaper.
I've also done the same thing with a power hand-sander (orbital kind). It leaves swirly marks at first, but that's ok as long as you don't press down too hard. After you get it smooth, just use the sanding block (mentioned earlier) and run it lengthwise until the swirly marks disappear.
I use this same technique through all the stages of paper: 220, 320, 400, 600 and 800.
Then strop it to death with an aggresive angle.
Each step sharpens the blade as you go.
Dan
p.s. edited to add
You may notice 2 things - you lose about 3/64" of your cutting edge, and gain about 1/8"-1/4" in the bevel. You're really not removing a lot of steel. Just takes patience to make it look good.
