creating a solid from connected surfaces

Yea, but...... (assuming I've got this right)
What has to be done is to perform 5 merges and then solidify.
For an stl (planar facets) if there aren't any holes in a volume definition; Edit / Definition, Edit / Feature Properties and select Make Solid.
To tell the truth I've never imported an STL, but this is the normal closed quilt to solid workflow. There's, of course, a lot more that can go into it depending on the mesh.
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No i don't want to import an stl, but create one and for that I need solids.
wzzl

: hi all, : can I, say, create six connected surfaces in a cube shape and make pro-e : think it is a solid ? : this is mainly for stl purposes : : wzzl
For a 'watertight' quilt enclosing a volume, you can create a solid by 'Edit>Solidiy' which completely fills the quilt with solid; or by 'Edit>Thicken' which makes it into a hollow, but 'watertight', shell. Completely enclosed hollow volumes are frowned upon because they trap large amounts of very expensive resin inside. Completely filled is also frowned on by users because the SLA process gets quoted by time and material, both of which rise exponentially for filled solids as compared to shells.
For open quilts (absent a side, or with holes, cracks) the only option is 'Edit>Thicken'.
Both of these reference Wildfire commands. Either of these produces a solid which can be faceted for an STL file.
David Janes