Hi Steve,

> I have made some more closed 2 rail sweeps and they are
> producing edges with gaps as with the first model and
> causing the same problem.

Could you show me one? I displayed the objects with Style = "sweep" from your example above, and did the sweep and I get closed edge curves on the sweep result.

As far as I can tell in your example, the edge that you are offsetting did not come directly from the sweep, it seems to be the result of a fillet or something like that.

- Michael