Join Date: Sep 2007
Location: Baxter, Tennessee
I now have a vacuum chuck, cole jaws, and several other homemade ways to reverse turn a bowl, however for many years, here is what I did.
I start all of my bowl mounted between centers. I rough out the outside and turn a tenon for the chuck. This is usually on the tailstock end. I leave the mark the tailstock leaves. Sometimes this requires turning the portion near the tailstock down to 3/4" or less so it will fit in the chuck once the big tenon is seated i the jaws.
When the bowl has been hollowed and ready for the bottom to be finished I simply put a rubber since stopper over my chuck and reverse the bowl so the opening fits over the chuck. I bring the tailstock up and place it in the original hole. Apply some pressure and your ready to reshape the bottom. I turn all of the bottom except that last little tenon. I make it as small as I dare and then simply carve it away off the lathe.
If for some reason you have to remove the little tenon to fit the bowl in your chuck jaws. Simply turn a round piece that fits snugly inside the threaded portion of your chuck jaws. center drill this on the while it's on the lathe using something like a 1/4" or 5/16 drill. Now while the bowl is still in the chuck place this tenon in the threaded portion and push the drill down through it to mark a center on your bowl.
If that last part isn't clear I'll try to take a photo of my centering jig later when I go to the shop.