@TigerMike: I was not able to replace face as you suggested, did you try it actually?
The only way I know to create these shapes is to use loft guide with 4 cross sections and at least one guide, as in the video. It is always some work to get every thing correct.
Your sketches must be perfect, meaning every point that is common to several planes must absolutely be at the same location in each plane. The best way to ensure it is to move each common point a little bit and go back to the initial location: all the connected lignes must blink, or the point is not common to all the objects.
After loft, you will have 2 remaining lines on the body, just select them and delete.
I was addressing the original request to make a seamless surface where a hole is plugged. Replace Face works most of the time but not always. Here’s an example. Note it is not the oval bowl as shown originally.
thanks for the answer. I was trying to perform “replace face” from a flat to a curve surface.
With 2 curve surfaces, it works great, even when they don’t have the same curvature, at least on revolved shapes. I learnt something which is always nice