Tips for painting primed metal doors include examining the door for flaws, sanding after application of primer, painting with a mini roller instead of a paint brush and allowing the paint to dry adequately. Before painting, the entire metal door should be primed and not just spots. Full priming makes paint stick easier and creates a uniform smoothness that avoids unsightly blotches.
Primed metal doors should be thoroughly examined for surface flaws that are likely to be more evident after the application of a topcoat. It's easier to spot flaws under bright light once the primer coat has dried. Use spackling material to cover flaws. These areas must be sanded over before applying a fresh coat of primer. Hand sanding with nonclogging sandpaper is recommended to remove all visible signs of bubbles, dust and lint.
After sanding, vacuum debris and wipe down the entire door using a clean damp cloth. Mini rollers made of high-density foam work best for painting primed metal doors. Mini rollers spread paint evenly without creating bumps and brush marks. Use a paint brush to paint the edges of panels and windows and use the foam mini roller to paint a majority of the door's surface. Because these smaller rollers spread paint thinly, two coats of paint are needed to achieve a good finish.