My newly purchased, 16 year old, stucco home is showing rusty nails through the paint in the exterior window trim. A professional painter has told me that these (not countersunk, not finishing nails) and some areas of rotty wood, can be covered in bondo. However, I was sure that I once read in FineHomebuilding that this would not be appropriate. I have always heard that 'rust never sleeps'. How should I remove all rust and what product should I use to replace some small areas of rot? I know that there is an epoxy product on the market for wood restoration - but I was recently reading a post regarding checking in a weathered exterior window sill and the owner was advised to fill the checking only and leave no product on the surface as moisture would be trapped underneath. Help!