Sharpening a Gouge
Sharpening a Gouge
Re-shaping the bevel
The victim is a 1/2" Stiletto brand cabinetmaker's gouge recently acquired in a lot of vintage chisels. It looks like it's been well taken care of, as the blade is full length, and the edge is perpendicular to the axis of the blade:
The right side of the photo above show a bit of rounding over on the right side corner, but it's not excessive - most likely its from normal wear.
Turning it over reveals a little more of it's history - it appears as if the previous user used a grinder or a coarse stone, but didn't take it past that to get his edges. You can see the striations left by the previous sharpening:
It would take quite a bit of work to remove enough material by hand to smooth these marks out of the bevel. I decide it would be better to start a new grind. I'm using a Tormek, however just about any powered grinder or sander would work as well - I like using a wet wheel, as the water keeps the steel from overheating and ruining the temper. If you use a dry system, keep a jar of water handy and frequently dip the tool into it to keep it cool.
Here, I'm using a jig created expressly for the purpose of reshaping curved tools:
It's a simple jig, easily recreated. Before I had this grinder, I used a belt sander rigged up to sit upside down on my bench, with a bar running across the belt. I used the bar to accomplish the same purpose, though didn't use jig, just did it freehand. The jig simply helps to insure a more consistent grind.
This gouge was in pretty good shape, and I only took enough off to create a slight hollow ground bevel that would make sharpening the rest by hand easier:
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 the same - less material to grind off at the stone. Here's a graphic of a microbevel:
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 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.