Hi Michael,

> Hmm, I'm not having any luck with joining the surface model to the solid base, and I didn't
> find anything regarding this specific in previous posts. Are there any tips for doing this?

You'll probably need to reverse the process a little bit - build the bubbly surface piece first, then trim that how you want it and use the resulting edge around the outside of the bubbly surface to construct a base piece.

It's unlikely that ZSurf is going to generate something that matches a predefined fixed base within enough tolerance to join it.

- Michael