Wash the fiberglass with a sponge using a solution of 1 cup of liquid laundry detergent and 1 gallon of warm water. Rinse the soap off by spraying the RV with a garden hose. Allow the surface to dry naturally. Use a product called MEK and wipe down the fiberglass with it to remove grease and oils.
However, waxes and polishes only work for fiberglass RV exteriors with none to moderate oxidation. To clean moderately oxidized fiberglass, nothing more than elbow grease and a polishing compound (or any other liquid abrasive) can do the trick. In general, you need to rub the oxidized layer with polishing compound or oxidation remover.
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Frequently Asked Questions
What do you use to clean a fiberglass camper?
For fiberglass, the best solution is a wash-and-wax product that both cleans your RV and protects it for the future. Most are environmentally friendly as well, which is particularly important if you're planning to clean your RV in a campground. Again, if your RV has decals, avoid the pressure washer.
What can I use to clean the outside of my camper?
Use a mild soap that is compatible with the surface of the RV. Use a long handled brush with soft bristles to reach the high areas and a wash glove or mitt for the easy to reach areas. Rinse the area you plan to wash first and always wash from the top down.
How do you remove oxidation from fiberglass RV?
To restore oxidized RV fiberglass, you simply need a little elbow grease and some polishing compound. Apply the polishing product with an ordinary non-scratch kitchen scrubby sponge. Work the polish into the surface by hand, and polish until you don't feel any more resistance. Allow the polish to dry and haze over.