Clean the interior surface of your bathtub with a soft, nonabrasive bathtub cleaner and clean cloths. Rinse the tub and dry the surface.
Tape off any hardware you cannot remove with painter's masking tape.
Cut a square of plastic drop cloth large enough to fit over the open drain hole. Secure the plastic to the underside of the bathtub, directly beneath the drain hole, by taping it in place with the masking tape.
Protect any grate or covering over the cut out drain hole by covering it with masking tape. Trim the edges of the tape so they don't cover up any portion of the tub surface.
Tape the plastic drop cloths to the surrounding walls and lay one on the floor to protect these surfaces.
Brush etching solution onto the interior surface of the bathtub. Let the etching solution sit for 15 minutes to roughen the surface and prepare it for reglazing.
Remove the etching solution by rinsing it off with water. Dry the bathtub interior with clean cloths.
Spray epoxy-based primer over the interior tub surface using a paint sprayer. Apply a thin, even coat by moving the sprayer back and forth over the surface. Let the first primer coat dry for six hours.
Apply a second coat of primer in the same manner as you applied the first coat. Allow the second coat to air dry for at least 12 hours.
Fill up your paint sprayer with acrylic urethane-based paint for bathtub and shower surfaces. Apply a thin, even coat just as you did with the epoxy-based primer. Allow the first coat of reglazing paint to dry for four to six hours.
Repeat Step 10 to apply two to three more coats of acrylic urethane-based paint. Let your final coat dry for 24 to 48 hours. Buff it to a shine with a buffer before using the tub.
Remove the masking tape and plastic from the drain hole. Replace the hardware you removed before reglazing.