I'm attempting to edit an airfoil that has a sharp trailing edge and make the trailing edge blunt.  To do this I have been using the Split Surface by Isocurve tool.  It seems to work great, I am able to split the top bottom and side surfaces, then delete the parts I do not want.  Then I created the blunted trailing edge surface using the Edge Curves option, again worked great.  Atleast it looks great in Rhino.  The problem is when I export it as an IGES.  I'm doing CFD work, so I need the IGES file to generate a grid in GridTool.  Like I said, the geometry surfaces look fine in Rhino, but once I import the IGES file I created into GridTool the Geometry still has the sharp trailing edge even though I deleted a portion of it to make it blunt!  The surface I created for the trailing edge was there though.  I also see that the geometry I want, blunted trailing edge airfoil, is actual there, but it is only defined by NURBS curves, not NURBS surfaces which I need.  Anyone have any ideas?