I am working on a custom mold parting surface, trying to sweep a profile surface around the perimeter to be a parting surface.  When the swept surface is made, there is a gap (between swept surface and part surface) at several areas along the path, as much as 0.5mm.  This will of course not knit, and also i cannot fill surface for this gap either.

Perhaps I'm missing something in the sweep options?

The surfaces are SurfaceSweep8 and PartingLine1(2). 

Any advice is greatly appreciated - thank you in advance.

Scott