How to create a filled single part from an assemby?


I’m looking for a method to create a single part (without internal details) from an assembly.
My assembly have internal design I don’t want to publish.

In other words I want to merge the 2 components into one and fill it to hide internal design.


Did anyone ever address this? I’m trying to do the same thing, with a pretty elaborate manifold. I don’t want to show the internal flow paths, but if I just do a shrinkwrap, it doesn’t fill the internal cavities, but it does wrap up external features I don’t want it to.