There is no real difference in technique. And no, stick sharpening will not add any concavity to the edge.
Sharpening is grinding away flat planes to intersect at the edge. Some people like to add a more obtuse 'micro' bevel to finish off the working edge. Sharpening will not affect the primary blade grind unless you are sharpening a flat ground blade with the blade flat on the stone. For a flat ground blade, the grind already defines a V. The sharpening angle will be greater than the angle defined by this primary grind. In a hollow ground blade, the blade surface will fall away from the sharpening angle.
Using stones freehand, or stick sharpeners in fixtures, the sharpening angle will probably be in the 15 to 30 degree range (per side). The best angle to use will depend on the steel, the grind of the blade, and the intended cutting task. The angle itself is much less important than maintaining that angle consistantly while sharpening. That is why some people find using stick sharpening devices helpful, the angle is maintained automatically.
So, hollow and flat ground knives are sharpened in the same way. Knives with a convex (Moran) grind or secondary (cutting) bevel are a little trickier.
Take the time to carefully read, think about, and practice the techniques described in Joe Talmadge's
sharpening FAQ here at BFC.
Happy sharpening!
Paracelsus
[This message has been edited by Paracelsus (edited 04-28-2001).]
