Hi Danny,

I was on the right track. I didn't hide my curves and was selecting those instead of the surface edges. Must remember that for the future.

This method seems to have a different sort of limitation. The blend creates a gap as shown in attachment 1. This can be adjusted out somewhat but creates a curvature then at the bottom per attachment 2. Have I missed a setting?

My problem with the networked version is, I think, that the curves are traced from paper plans of varying quality which have been scanned, jpeged and coffee stained to within an inch of their lives. The accuracy of the resulting nurbs curves is questionable and any problems between the networked surfaces shows up at the joined edges. I have rebuilt my curves in the vertical which helps a lot. I did not try it in the horizontal. Perhaps I should have. If I rebuild all curves, will a hull as curvy smooth as the lofted version be the result? The problem in the horizontal that I can see is that if I rebuild the segments of the curve I get better but still wavy curve segments. If I join the segments and rebuild as an individual curve, the curve shape changes slightly, enough for the horizontal and vertical curves to no longer intersect. This would then require me to snap curve points.