Be sure to visit the Hand Tool Headlines section - scores of my favorite woodworking blogs in one place.  Also, take note of Norse Woodsmith's latest feature, an Online Store, which contains only products I personally recommend.  It is secure and safe, and is powered by Amazon.

Search

The Difference Between a Hollow Grind and a Micro-Bevel

This is taken out of the sharpening gouges article, just as a quick reference. I may add to it as time permits and ideas come...

Hollow Grind

A hollow grind simply refers to how the wheel cuts the bevel on the edge of the tool (this graphic is a bit exaggerated):

 

It's the same basic idea as a microbevel - but instead of creating an additional, smaller bevel, you are removing the bulk of the existing bevel by imparting a curve to the middle of it. The end result is basically the same - less material to hone off by hand at the stone.

Micro-Bevels

Here's a graphic of a microbevel:

Which method you use usually depends on what tools for sharpening you have available for shaping the initial bevel on the edge. I have a Tormek for shaping bevels, so hollow grinding is the norm. Someone who uses a belt sander, LV Mark II, or LapSharp (or non-powered on stones or sandpaper on glass) would obviously choose the micro-bevel approach. Either way, a truly sharp edge come with honing, not shaping - for that I personally prefer oil stones.

I have used both methods - edge retention for each is the same, IME. The main difference you have experienced might be simply the angle the beveled edge is ground to. If the angle is too shallow, then the steel won't hold an edge well... Too steep of an angle, and the chisel is harder to push through the wood. Better steel in a chisel means it can hold an edge better at a shallow angle, which is the main difference between a premium chisel and a cheap one.

I shoot for 20 to 25 degrees for a paring chisel (no mallets!), 25 - 30 degrees for a bench chisel (light mallet use) and 30-35 degrees for a mortising chisel (heavy mallet use).

It's a good idea to be conservative on how much material you remove from any tool. Grinding a new edge on a tool should be performed only when absolutely necessary; keeping an edge sharp with regular maintenance will usually make re-grinding the edge un-necessary except after very long periods of use. More than that and you waste good metal, shortening the life of your chisel or gouge unnecessarily. They can wear quickly if over-sharpened.

Hope this was useful information.