How to Remove Stains From Fiberglass Bathtubs & Shower Stalls

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Things You'll Need

  • 2 nonabrasive sponges or microfiber cloths

  • Liquid dish soap or Castile soap

  • Baking soda

  • Nail polish remover or turpentine, if needed

  • Cleaning brush with soft nylon bristles, if needed


Baking soda is a natural, mild abrasive that's safe to use on fiberglass tubs and showers.

Rinse the tub and shower after each use to reduce the buildup of soap scum.

Leave shower curtains or doors open and open the bathroom windows or run a fan after bathing to discourage mold and mildew.


Always test a product such as acetone or turpentine on an unobtrusive area of the fiberglass surface to make sure it doesn't affect the color before you apply it to a larger area.

Wipe solvent off before you rinse the stain to keep the solvent from going down the drain. Don't get solvent on plastic, such as drain covers.

Never use any kind of polish or wax on a shower floor or inside a bathtub on the bottom surface or the top of the sides. These products leave the surface slippery and could result in falls and serious injuries if applied to areas where you stand or the areas where anyone might grip the tub when getting in and out.

Soap scum causes a dull discoloration in fiberglass tubs and showers.
Image Credit: Jupiterimages/ Images

Removing stains from fiberglass tubs and shower enclosures requires the right cleaning solutions and careful application to avoid damaging the finish. Fiberglass bathtubs and showers may develop stains from hard water or mold and may be marred by paint and adhesives. Fiberglass scratches easily; full stain removal with gentle methods may take more than one attempt.


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Soap It Away

Step 1

Apply a mild liquid soap to the stained area of the fiberglass with a sponge or soft cloth. A thick liquid soap such as Castile works well on shower walls.

Step 2

Leave the soap on the stain for 15 minutes, or up to an hour for a tough stain. When you return, rub the soap over the stain in a circular motion before rinsing.

Step 3

Rinse the soap away thoroughly with warm water. If any sign of the stain remains, repeat the procedure or try the next method.


Scrub It Away

Step 1

Mix baking soda with a small amount of water, such as 1 tablespoon of baking soda to 1 teaspoon of water, to create a thick paste.

Step 2

Dip a moist sponge or soft cloth into the baking soda mixture. Rub this mild abrasive on the stain to remove it without scratching the fiberglass.

Step 3

Rinse the baking soda off with warm water and wipe the surface with a dry soft cloth.


Bring on the Big Guns

Step 1

Open the bathroom windows and turn on the fan if there is one. Apply a quarter-size amount of nail polish remover or turpentine to a sponge or soft cloth.

Step 2

Moisten the stained area with the solvent. Apply more if needed and rub it in well. If the stain includes paint or adhesive, you'll need enough solvent to penetrate the material that's adhering to the fiberglass.

Step 3

Allow the solvent to soak in for an hour. Scrub the stain with a soft nylon brush. Dip a sponge or soft cloth in hot water and rub the area again if the stain is stubborn. Remove the residue with a clean damp sponge or cloth.


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