Remove all loose paint and debris from the camper's roof, using a wire brush to break the deposits free from the camper's roof. Clean off the debris with the broom.
Cover the camper's air conditioner, side walls, windows and door with plastic sheeting. Hold the plastic sheeting in place with masking tape.
Wash the camper roof with a roof cleaner according to the cleaner manufacturer's instructions.
Cover all seams and any small holes in the camper's roof with roofing seam tape, using scissors to cut the tape to size. If the seam tape uses a paper liner to protect its adhesive, remove the paper liner before pressing the tape onto the camper roof.
Mix the roof sealant, using an electric drill equipped with a mixing paddle. If the roof sealant uses a catalyst, combine the sealant and catalyst before mixing with the electric drill. Continue to mix the sealant until it has a uniform color and texture.
Fill a painter's pan with the roof sealant.
Seal all of the flashing around the camper's roof vents with the roof sealant. Use a paintbrush to apply the sealant.
Apply a layer of sealant to the camper's roof with a paint roller, following the sealant manufacturer's recommended coverage rate. Some sealant manufacturers recommend one heavy coat of sealant, while others recommend several thin coats.
Let the camper's roof sealant dry completely before removing the plastic sheeting.