So, I'm assuming you turn a really thin inner bowl (with a hole in the bottom) plug the hole with a cork reverse it on the vacuum chuck, turn the lip on inner vessel, boil the inner vessel until it becomes flexible enough to work it inside the other vessel, insert balloon and blow it up, once the wood dries and becomes rigid you let the air out of the balloon and 'poof' a vessel inside a vessel. Did I get it right? How thin did you have to turn the inner vessel for it to become flexible enough after boiling to get it in there.
This is super cool, I definitely am going to have to play with this idea