I'm mounting using a wood screw and large washer on the side to hold things in place. Then I bring the tail stock up with a flat fitting on it and that seems to hold stuff in place.
I had some trouble on the last one I tried in that, for reasons that only a wood turner could understand, I'd NEVER sharpened the parting tool! Wasn't pretty. I sharpened the tool and tried an old piece from a vortex bowl I'd made before and it worked pretty well, but I ran it at 500 RPM.
I'm not worried about a little tear out because there will be a lot of sanding later; there always is. I don't like cutting the circles in half and glueing them back together. I've got a scroll saw and have tried that, even with the spiral bit. It works but takes a lot of time. That's not really an issue, but the bowls I've made where I cut the circles on the lathe seemed to come out so much better. Probably an aesthetic thing, but that's the way I'm going to do this.
I appreciate you guys jumping in on this and will, in fact, post pictures as it goes. I've come up with a way of turning Purple Heart a beautiful forest green. I know; why would you want to. Probably because I've never seen anyone else do it. Tomorrow I'll sand the big block and I'm going to do the "Greenerizing" process to see how it affects the other wood. I know it darkens Walnut but I don't know about the other pieces. Doesn't soak in so it's easy to get it off. I can post before and after pictures of all that too.
Gotta' love weird processes like this. But turning bowls gets boring after awhile, and I've given so many to all my relatives that I need to come up with something new or they will start returning the gifts, or use them for firewood.