Do the instructions say to be used over bare steel what do the instructions say.
This is how it appears on the can and I quote :
Surface should be clean, dry, and free of grease, rust, and wax. 2)
Mask off or protect areas from overspray if necessary. 3)
Allow can to warm to room temperature before use. 4)
Shake until mixing ball rattles, then continue to shake for at least two minutes. 5)
Move can with dusting strokes letting paint become tacky between coats. 6)
Only apply enough paint for coverage; excessive spraying may result in runs. 7)
Never spray with the valve partly open; press spray tip all the way down. 8)
If spray stops or becomes irregular, rotate spray head from side to side without removing from valve. This will usually clear the spray head. 9)
After use, invert can and spray for 2 to 3 seconds to clear valve and spray tip."