Lidding a hollow form

Ray Carson - Lawrenceville, NJ
Hello Wood Central wood turners. I don't post often and haven't in quite a bit but I have been woodworking. :)
I'm currently working on a hollow form which I hope to post pictures of very soon. I'm in the process of making a very shallow or low lid with a finial and have come upon a dilemma of how to hold and turn a piece of wood about 4 1/2" in diameter, about 1 inch thick. I want to make a shoulder for it to sit in the hollow form opening and then have the finial glued into that. I'm a bit perplexed on how to hold the disc without using a four jaw chuck and leaving marks on the portion going into the hollow form. I tried using a four spur center but that was very inefficient. The four jaw chuck I have doesn't expand enough and again, I don't want to leave marks from that chuck.
What can I do?

© 1998 - 2017 by Ellis Walentine. All rights reserved.
No parts of this web site may be reproduced in any form or by
any means without the written permission of the publisher.