Open windows or turn on the bathroom fan to ventilate the room.
Remove the metal drain trap and scrub the bathtub with the cleaner included in the kit. Scrub all crevices and corners thoroughly.
Rinse the tub with warm water.
Sand the entire tub surface with 120-grit waterproof sandpaper. Periodically wet the paper with warm water. Remove rust with a rust-removing solution or sand the rust off.
Rinse the tub with warm water and dry with an old towel. Allow the tub to air-dry.
Apply masking tape next to the perimeter of the tub to protect the wall adjacent to the tub. Tape plastic bags over all faucets.
Pour the bathtub hardener from the kit into the coating and stir with a spatula. Replace the coating lid and shake until thoroughly incorporated.
Pour some coating mixture into the paint pan and paint the coating onto bathtub edges, corners and crevices.
Place the paintbrush into a sealed plastic bag.
Apply more coating mixture with the roller brush until you achieve an even coat. Store the paint roller in a sealed plastic bag. Allow to dry for one hour.
Apply a second coat with the paintbrush and roller.
Remove the masking tape and allow the coating to dry for at least 48 hours.