This is a problem has bugged me for a long time in various contexts so…
If I have an interior that is oversized to fit an odd shape
And I have an odd shape exterior
How can I reliably trim off the excess and combined the two part?
All too frequently, when I do do a boolean difference with the two, that works. But when I remove the trimmed parts and try a boolean union that fails.
The problem surfaces tend to have been created with SHELL. That might be a clue to the issue.
Then I have to do all kinds of tweeking and hope to find something. Is there some approved solution to this?