This product can indeed be used to paint over brass doors, however some preparation work will need to be done.
The doors will need to be sanded with a 120 to 150 grit sandpaper in order to roughen up the surface. Take care to cover all corners and angles. The doors must then be wiped down with a 50/50 mix of water and vinegar to remove all sanding residue and oils.
The
Stove Bright Primer Paint - 12 oz. Spray Can - 43299 can then be applied in even, light coats until good coverage has been obtained.
The doors can then be painted with a color of your choosing. As with the primer, several light coats will yield the best results. It is best to apply each coating of paint when the previous layer is still tacky.