After a day of sitting in a warm place, the epoxy is hard enough to grind. I am starting with a 36 grit zirconia belt with the flat platen.
The objective is to true up all four sides and make clean rectangles.
I want the slant back, but I cannot go too far. If I grind through, it will expose the threaded hole that the tang screw is in.
I used the water bucket here a lot. The epoxy is good, but no epoxy can stand the heat that will build up in a chunk of steel being ground down.
I start to round the handle by holding it at 45° and passing across the belt. Occasionally, I work the handle in the vertical position.
At this point I am checking the symmetry and working equally to make a nice oval cross section. I am dipping the handle in water just about every pass to keep it cool. If you expose the screw hole in the butt, you can plug it with a piece of brass like I did. ;-)
Here the handle is starting to feel good in hand.
Moving up to a 220 grit AO belt in the slack belt mode. I find this slightly burns the wood and darkens the burl considerably.
Here you can see the profile of the handle and how it will be in it's finished shape.