Hi Peter,

> Maybe you could please elaborate on that Michael.

Well, you could use some mixture of booleans to fuse together pieces that are more clearly intersecting, and in complex areas you can use Edit/Trim to cut individual curves into pieces and then pick which pieces to discard.

In complex situations, that kind of manual trimming should be able to get the job done where the booleans get confused.

If you would like to post a .3dm model file, I could help show you in some more detail.

- Michael