3 questions about naked edges

I work with turbine airfoils and often use 3D printing to show concepts. I continually run into “naked edges” on my solid parts.
What are naked edges? How do I prevent them? Once I have them how do I fix them? See attached picture.

The solid was constructed using a 2 rail sweep using the outer and inner cross sections as the rails and radial rays as the curves. The outer surface was capped and then the inner surface was subtracted from the center. If I use loft I seem to get more areas of naked edges.

Hello- Naked edges are edges that are not joined to may other edges in a Brep/polysurface. For 3d printing purposes you can get away with using the command JoinEdges where there are two edges to be joined but they are out of tolerance- just keep in mind that this is a hack and not a fix, suitable for concept models perhaps and for closing up nearly closed objects for 3d printing.

Can you post, or send (tech@mcneel.com, att’n: Pascal, the file and the input curves for your object?