How to Paint Brass Trim for a Fireplace

Mix the trisodium phosphate solution according to the label's directions. Wipe the brass trim clean to remove any dirt and soot. Dry with a clean cloth.

Sand the brass trim to roughen the outer surface so the paint will adhere. Brass trim often has a shiny outer coating that makes paint adhesion difficult if not sanded. Wipe the trim with a slightly damp cloth to remove all traces of sanding dust. Wipe dry with a separate lint-free cloth.

Apply the self-adhering plastic drop cloths to all surrounding areas. Self-adhering drop cloths have painter's tape on one or more edges, but use additional painter's tape to help hold the plastic drop cloths in place, especially on vertical surfaces. Use as many self-adhering plastic drop clothes as needed to thoroughly cover the floor, the fireplace mantel and even walls where necessary.

Put on the dust mask. Spray-paints are easily inhaled because of the paint mist that drifts during application.

Apply the heatproof spray primer according to the manufacturer's instructions and allow to dry for the time specified on the label.

Follow all directions on the heatproof spray-paint, including shaking the can for the amount of time for proper mixing. Spray a light coat of paint on the brass trim. Several thin coats of paint give better results than one or two thick coats of spray-paint. Let each coat dry before applying the next. Remove the painter's tape and drop cloths after the final coat of paint.

Follow the manufacturer's instructions for curing the paint. The curing process sometimes involves heating the paint for a specified amount of time.