Refinish a fiberglass shower by sanding the entire surface, ensuring it is thoroughly clean and applying up to three coats of a gel finish. Follow the manufacturer’s directions concerning the time for the finish to harden before using the shower again.
A small, electric palm sander works best for most showers. The device is small enough to reach into most corners of the unit, but significantly reduces the work that sanding the shower stall requires. Take the time to cover all the areas but avoid gouging the fiberglass with the sander.
Provide a thorough cleaning of the tub to ensure that the new finish adheres to the fiberglass. Use a cotton rag dipped in acetone to wipe all surfaces. The acetone dissolves any oils on the walls. Make sure that none of the dust from sanding remains, as it causes a rough finish.
Tape plastic drop cloths around the shower to protect the area from dust and surrounding surfaces from overspray. Put on a respirator to protect the lungs from the toxic spray. Fill the container with the gel and apply a light coat for the finish. Allow it to dry until tacky, and apply a second heavier coat. When the second coat is tacky, apply a third coat.
Remove the drop cloths and tape. Once the gel finish dries, wipe it another time with a clean cotton rag dipped in acetone.