surface with edge cloning
Select either of the objects, enter edge sub-object mode. Select the
side edge and shift-drag. (Shift-dragging means that you keep a shift
button pressed on the keyboard while dragging something with the mouse.)
This is how you create polygons by shift-dragging the edge selection.
Select several boundary edges.
Shift-and-Drag to Create several polygons at once.
Modifying topology with Welding
Delete a polygon. Select a vertex.
Enter Weld Target mode in Vertex sub object mode.
Drag the vertex over another. Release the mouse button. Vertex should
to Page Four
2001 by George Polevoy