About Filling Loops in a Parting Surface
You must fill any loops that lie on a parting curve before completing the feature. Depending on the type of loop to fill and your needs, there are several tools available:
• Use the Fill Loop tool to fill closed loops and to specify an offset for the fill.
• Use the Shut Off tool to fill both open and closed loops so that the patch is tangent to the bounding surfaces.
• Use the Loop Closure element in the Shadow Surface dialog box to fill open and closed loops when creating a shadow surface.
• Use Insert mode to create surfaces using copies that were made before creating a hole in the design model.