How to Clean Dull Fiberglass

••• spray of water in shower image by laurent dambies from Fotolia.com

Fiberglass is a durable product that is used to construct shower inserts, boats and other outdoor vehicles. All new fiberglass contains a clear polish, called a gel coat, which protects the material from damage and maintains an attractive appearance. Over time, the gel coat becomes scratched or covered in soap scum and oxidation which makes the fiberglass appear dull. Restoring the shine to fiberglass requires a thorough cleaning and polishing.

Fill a 5-gallon bucket with 1 gallon of water and 1 cup of liquid laundry detergent. Mix the solution to dissolve the soap.

Insert a sponge into the bucket and wash the entire surface of the fiberglass to remove dirt and dust. Rinse the fiberglass with clean water to remove all traces of the soap residue and allow it to dry.

Apply 1/2 to 1 cup of acetone to a cloth and wipe down the entire surface of the fiberglass with the cloth. The acetone removes any surface grease that the soap did not remove.

Polish the fiberglass surface with an abrasive, rubbing compound to remove small dents and imperfections. Apply 1 tbsp. of rubbing compound to a rag and rub the fiberglass in circular motions until the surface looks smooth. When the entire surface has been polished, wipe it down with a clean towel to remove excess rubbing compound.

Apply 1 to 2 tsp. of liquid automotive wax to a lint-free towel. Apply the mixture to the fiberglass surface using circular motions until the entire surface is covered.

Rub the surface of the fiberglass lightly with a clean, lint-free cloth to remove wax streaks and buff to a shine.


  • If the fiberglass surface has mildew on it, add 1 cup of bleach to the soap and water solution in Step 1.
  • Wear gloves when cleaning to protect your hands from acetone.


About the Author

Kimberly Johnson is a freelance writer whose articles have appeared in various online publications including eHow, Suite101 and Examiner. She has a degree in journalism from the University of Georgia and began writing professionally in 2001.

Photo Credits

  • spray of water in shower image by laurent dambies from Fotolia.com