Difficulties Creating a Watertight Volume

[RFerman]

My present problematic issue is turning a set of enclosing surfaces into a 3D solid. There are other Forum posts on this topic and I have looked through them. Some were useful, but my problems remain unresolved.

Please refer to the attached.

I have extended the of all surfaces so that they cross. When I did that, I used the Union command to connect the extensions to the original surfaces.

It looks like there may still be some very thin gaps along the Leading_edge and Trailing_edge surfaces. I have tried a couple different techniques: Surfoffset and Thicken. Neither of these worked when I next tried to create a solid with the Surfsculpt command. I would normally get an error: 'Solid creation failed, no watertight volume detected.' Except, there were a couple times I got no error – nothing – and no creation of a solid.

I executed an Undo to get back to geometry that existed before I tried Surfoffset and Thicken. That is the geometry per the attached.

By the way, one my recent attempts to use Surfoffset did not work. I was trying to close up the Leading_edge and Trailing_edge intersections. The command just did not function.

Any advice or assistance will be appreciated. Thank you.

[Valentin-WSP]

Create a 3D solid by using "LOFT" from your called "Blade_caps" to the other "Blade_caps" (works best if done in 4 parts, loft the top, then the sides, finally the bottom).  This will eliminate any gaps, allowing you to make a 3D solid.  You can work-out the side radius "Trailing_edge" by providing a path when you "LOFT" or modify the solid afterward - using other methods. 

To make it a solid, "UNION" the surfaces and then "SURFSCULPT". 

[RFerman]

Valentin, Thank you for taking time to look into this. I am starting to
figure out a method of lofting that will preserve the intended geometry,
mostly as defined by the 'Blade_working_surface' and the
'Blade_back-side_surface'.
One approach that I am also exploring is using the 'Blade_caps' per your
suggestion. I may need to define an intermediate section, again, in order
to preserve geometry.
Also, it is not clear to me what the technique is in doing the lofting in 4
parts per your suggestion. As I experiment with the LOFT command, and learn
how to use it, your suggestion may become apparent. Best, Randal