Rust on a steel window frame looks alarming, but in most cases it is a maintenance problem, not a death sentence for the window. Understanding where it comes from makes it easier to fix.
Where rust starts
Rust needs water and oxygen. On a steel window, water gets in where the paint has failed or the glazing putty has cracked. The bottom rail and the glass rabbet are the usual starting points, because water collects there.
How far is too far?
- Surface rust: clean, prime and paint
- Scale and pitting: blast or grind to bare metal, then prime
- Perforation: cut back and weld in new steel
Rust also expands as it forms. Rust building up between the frame and the masonry can push the frame out of line and crack the wall, which is why early repair matters.
Stopping it from coming back
Bare steel starts to rust again within hours, so it must be primed quickly with a rust-inhibiting primer. After that, a good finish coat and sound glazing putty keep water out. Check your windows every few years and touch up paint before it peels.
Questions about your own windows? Call (215) 555-0163 or request a free estimate. See also our steel window repair and steel window restoration services.