A rosette is a flat, circular ornamental disc with a floral or geometric relief pattern pressed or cast into its face. Rosettes are welded at cross-points in ironwork, at the intersection of vertical and horizontal rails, or at the center of a panel to provide a decorative focal point and conceal weld marks.
Yes. For exterior applications, steel and cast iron rosettes should be primed and finished along with the rest of the ironwork assembly. The face relief of a rosette can trap moisture in its crevices, so thorough coating of all surfaces during finishing is important for long-term rust prevention.