"Gerald Ross" wrote in message
...
Some bowls dry with a usable dovetail pretty much intact, some wind up
with an oval hole. I often chuck them in the cole jaws and re-do the
dovetail before finish turning. Recently I made a jig to round up the
dovetail with a router. This requires a 15 degree dovetail bit but has
worked well for me. If anyone is interested I can do the pictures &
description.

Have you ever considered using a pin chuck for roughing and leaving the
pillar intact in the drying bowl? Makes an easy recenter because the hole
remains full size in the direction of the grain, guiding the bit to center
and removing the face grain symmetrically.

Additional benefit in that you can re-turn the outside and bottom to
circular toward the headstock with no interference. It can also provide you
with support by snugging the tailstock up after re-chucking in the dovetail,
allowing a faster hogging rate as you turn the interior for thickness and
circularity. Protects the turning from an accidental dismount until it's at
its lightest and best balance, too. Pictures of the procedure, using both
pin chuck and pin jaws at http://personalpages.tds.net/~upgeorge/index.html
for your examination.

14 degree bit, easily obtainable, will work as well. At a quarter inch
depth the degree difference is certainly within the elastic limit of the
wood.