Hi Michael, thanks for your reply. I had come to the conclusion that this surface would be need to be created as a whole and then trimmed. My issue is that I am unsure on the best method to create the construction curves for a network. I did try to make a series of modified loft curves almost like a height map that were offset from the outer edge that connects the two cones. When lofted the surface breaks up as it reaches the end points on each cone.

Jim