why does "blend" not work here?

 From:  bemfarmer
4993.7 In reply to 4993.5 
Finally got merge and blend to work. Found it to be very tricky.
The easiest way to avoid the 2d curves on the outer objects, was to style them all red, and then hide them with the eye selector.
Then select all the surfaces and run merge on them.
Then select center object surface, then one of its edge U shapes, select one of outer U edges, and blend. Repeat for all outer objects.
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