Need help with Naked Edges


I am a student new to Rhino and is currently working on a catamaran model. But I am struggling with issues on naked edges and also joining the hull parts together to make them into one solid. I found out this command ‘JoinEdge’ is possible for some areas but some of the gaps are just too big and I understand this command will overwrite the absolute tolerance values and cause inaccuracy to other parts. Is there any advice on how to fix the issues?

Attached below are screenshots of the issues:

This is the 3dm file which I am having trouble joining them all together as one solid item.
TRY8.3dm (574.6 KB)

Any help or advice is much appreciated.
Thank you.

  1. Surfaces only join at adjacent edges. You can’t join the edge of surface to the middle of another surface. Trim the surfaces where needed to create adjacent edges.

  2. Some of the trimmed surfaces do not intersect. Untrim and Trim again. Do you change the absolute tolerance after starting the project, either directly or by changing units? If so making the absolute tolerance smaller does not alter geometry which was already created.

TIP : This is why it is important for beginners to create curves and surfaces that are as clean & simple as possible. When drawing the curves, use the O-Snaps at all times and keep the curves simple / with the fewest number of control points.


  • If there is a surface that will not join on multiple edges, I’d just delete it.
  • Make a new surface using those existing edges. Rhino treats edges as
    curves in most cases.
  • If not, it’s because they might be split into multiple edges.
  • In that case : Use Curve → From Objects → Duplicate Edges.
  • Then, join those curves together to make one single curve.
  • You can now build a new surface back in the opening … I like
    Surface → Sweep 2 rails.

okay thank you for your advice @davidcockey @schultzeworks! Will try it out and see how it goes.