look for the button under part features that says "promote", if that's greyed out then you have to RMB what ever is in the feature tree below origin folder and say "copy to construction" first, then promote it.
If there are screwed up or missing faces then this might not work so well.
"Brian" wrote in message
A supplier has sent me an Iges file which seems to open OK into INV but it
comes in as surfaces only. Is there an easy way to convert these surfaces
into a single solid lump?