Cleaning a fiberglass shower can seem like a daunting task. Fiberglass showers are strong and durable, but over time they pick up soap scum and mineral deposits that make them appear dull and dirty. Harsh abrasive cleaners are not an option for fiberglass since they scratch the surface, permanently dulling and damaging the appearance. Using a squeegee after each shower will prevent much of the soap scum and minerals from forming deposits, but when cleaning becomes necessary, use these techniques to restore your fiberglass shower to its original appearance and keep it that way.
Keep a spray bottle filled with white vinegar in your bathroom. Spray the shower walls and floor with a generous amount of vinegar several times a week and let it air dry. This will eliminate much of the need for scrubbing later.
You can clean your fiberglass shower with shampoo or dish soap to remove mild soap scum and water stains. Mix white vinegar with a little shampoo or dish soap in a spray bottle. The soap keeps the solution from evaporating too quickly while the vinegar eliminates water deposits. Spray the solution on all surfaces and use a non-abrasive scrubbing sponge to clean the area. Rinse and dry for a clean shower.
When soap scum and water spots are visible, spray the shower with white vinegar. Then, dip a damp scrubby sponge in baking soda and scrub the shower floor and walls with it. Rinse thoroughly and use a squeegee or soft towel to dry. If you need a little extra power, use borax instead of baking soda.
Stubborn stains require a little extra time and effort. Sprinkle baking soda on stained areas. Saturate a paper towel with vinegar next and lay it on top of the soda. Wait half an hour to an hour and then use a nylon brush to scrub off any remaining stains.
Rust and Hard Water Stains
Rust and hard water mineral deposits often require the use of commercial cleaners, so make sure you have proper ventilation and wear gloves when using them. Apply a liquid rust and mineral deposit remover according to package directions. These products are acidic so only use them if necessary, and don't let them sit on the fiberglass any longer than necessary as they may etch the surface.
The task of cleaning a badly neglected fiberglass shower may start you thinking about replacing it, but try this instead. Buy a can or two of fume-free oven cleaner; make sure it's fume-free, not the regular kind. Standard oven cleaners may contain lye, which will damage your fiberglass shower.
Spray a thick, even coat of oven cleaner, starting at the floor and working your way up. It's foam, so it will cling to the shower walls. Let it stand for an hour or longer as needed, and you'll need less effort than you thought to remove the caked on soap scum and mineral deposits. Repeat if necessary.
Use fiberglass boat wax for a protective coating on the walls of your shower that allows water to run right off. However, do not use it on the floor, as it leaves a slippery surface.