fixing/ patching an imported solid

Not sure about where you would `right click', but are you talking about running import diagnosis? I guess I do it so often, that I don't even remember exactly how to tell somebody.
Right after importing the body, rmb click on the imported feature in the feature tree and choose diagnosis. This will allow you to fix gaps and bad faces. This feature has been improving with every release if SW, and almost always works for me.
Hope this helps.
jk

thank you, jk !
on this model, it shows it as not needing fixing. then i get the message that says, under "what's wrong", "imported entity has 6 check entity errors".
the IGES file i did this before, a bunch of the faces weren't displaying. that was the time it showed it needing fixing, and "it" fixed "it" (sWorks patched up my model so it looked allright with no error messages.)
yeah, it's a good feature. guess i'm getting pretty biased in terms of liking solidworks.
anyway, it might be an acceptable defect, on this new model. not sure till i fix it, if it can be fixed.
on the imperfect model that is displaying, i'm using axis, point/plane, to add an axis normal to the surface. again to find the center of the spherical surface.

My suggestion would be to get a better export from the originating software. Say, this was exported from Pro/e, there's no need for you to be messing around with surfaces in SW if it was a solid in Pro/e. All you'd do is export it as an IGES solid from Pro/e and that would be the end of your troubles in SW. All the solid modelling kernels ~ ASUS, Granite, Parasolid ~ all understand B-rep, even if they don't all agree on surfaces. (Lots of it has to do with how each handles accuracy, not to be confused with precision, but related to it.) So, if, say you were doing an IGES export from Pro/e, you'd check (instead of surfaces) the Solids and Shells check boxes from the export interface.

Not sure what David means by that. Not sure if all systems support type 186 objects (in fact know of one, Rhino, that doesn't) or if it's a "kernel function".
Actually, ACIS "supports" (by previously stated definition) higher degree surfaces. I don't have any documentation but, once upon a time, did a little testing by reading and writing a data set of degree 3 thru 11 surfaces. MDT 6 (believe it's ACIS 6) supports degree 7 max (converts deg 9 & 11 to 7). Inventor (ACIS 7) exports all unchanged.
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This biggest problem with IGES is synching export and import options, data types, etc. Large percentage of the time STEP will be less prone to trouble.
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Could be. I don't know, but would venture a guess that STEP is just more coherent because it was started after more data types were established (some degree of standardization among the various major software developers?). I've never been quite sure why there are so many different ways of representing, say, a trimmed cylindrical surface in IGES (not so much a statement about IGES as it is about my low level of understanding).
[What I do find incomprehensible; that most present day developers don't bundle (at least fully AP203 enabled?) STEP translators with their basic software packages. Money grubbers.]