If your fiberglass tub has become stained or discolored over time, there are several methods you can try to get it gleaming white again. Proper cleaning and restoring the finish are key to making a fiberglass tub look like new.
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What causes fiberglass tubs to lose their white color?
There are a few common culprits when it comes to fiberglass tubs losing their bright white color:
- Soap scum buildup -Residue from soap, shampoo, and mineral deposits in water can leave a dingy, yellowish film on the surface of the tub.
- Hard water stains – Minerals like calcium and magnesium in hard water can leave behind spotty mineral deposits and stains.
- Mold and mildew – Humidity and moisture promote mold growth, which leads to black and brown stains.
- Bathing products – Chemicals, dyes, and oils found in bath products can stain and discolor the tub over time.
- Chips and scratches – Small scratches and chips in the fiberglass expose the mat underneath, making the tub appear dull and darker.
Luckily, with the right cleaning methods and re-glossing, you can often get your fiberglass tub looking bright white again.
How to clean fiberglass tubs
Start by giving your tub a deep clean to remove all built-up grime:
Supplies Needed
- Protective gear – Rubber gloves, safety goggles
- Mild abrasive cleaner or whitening cleanser
- Non-abrasive scrub brush or sponge
- Vinegar or tub & tile cleaner
- Soft clean cloths
Instructions
- Fill or partially fill the tub with warm water. This helps soften soap scum and stains.
- Apply a mild abrasive cleaner like Soft Scrub or Comet to the entire tub surface. Check the product label to make sure it is safe for use on fiberglass.
- Let the cleaner sit for 5-10 minutes before scrubbing. This gives it time to penetrate built-up gunk.
- Gently scrub the cleaner over stains using a soft brush, sponge, or cleaning pad. Avoid anything too abrasive.
- For stubborn stains, make a paste with baking soda and water. Apply the paste and let sit before scrubbing.
- Rinse thoroughly with clean water to remove all cleaner and lifted stains.
- Follow up with either white vinegar or a tub & tile cleaner. This helps remove any leftover soap scum and hard water buildup.
- Rinse again and use a soft cloth to dry the tub completely.
Repeated cleaning over time will help lift away built-up grime. For dingy tubs, consider using a whitening cleanser containing bleaching agents, like Soft Scrub with Bleach.
Removing specific stains from fiberglass tubs
Here are tips for removing some common stubborn stains from fiberglass tubs:
Hard Water Stains
Fill a spray bottle with undiluted white vinegar. Liberally spray the stains and let the vinegar sit for at least 15 minutes before scrubbing and rinsing. The acetic acid in vinegar will help dissolve mineral deposits.
Mold and Mildew
Make a baking soda paste by mixing 3 parts baking soda to 1 part water. Spread the paste onto black mold stains and let sit overnight before rinsing. The alkalinity in baking soda kills mold and bleaches stains.
Rust Stains
Make a paste with lemon juice and cream of tartar. Apply it to rust stains and let sit for 30 minutes. The citric acid will help dissolve the rust so you can scrub it away.
Hair Dye or Nail Polish Stains
Dab hair dye or nail polish stains with rubbing alcohol or nail polish remover on a cotton ball. Keep applying and rubbing until the stain fades. Rinse the area thoroughly when finished.
Refurbishing the fiberglass finish
If cleaning alone doesn’t get your tub sparkling white again, refinishing the fiberglass may be necessary. There are a couple options for refurbishing the finish:
Tub Refinishing Kits
Tub refinishing kits allow you to spray on a new gloss coat over the old finish. The process is similar to painting a car or furniture:
- Thoroughly clean and dry the tub.
- Sand the tub surface lightly with fine grit sandpaper.
- Wipe away sanding dust.
- Apply 2-3 coats per kit directions, allowing drying time between coats.
- Let cure fully before use, usually 48-72 hours.
With proper prep and application, refinishing kits can restore a smooth, factory-like finish. Cost is around $60-$100 per kit.
Professional Reglazing
For a longer-lasting solution, hire a professional to reglaze the tub. This involves spraying on a new layer of fiberglass resin. Professionals have industrial equipment to get a glass-smooth finish. The process involves:
- Removing the drain and hardware
- Scuffing up the old gelcoat
- Spraying on new white gelcoat
- Applying a clear topcoat
- Replacing hardware
Professional reglazing costs around $350-$700 and comes with a 2-5 year warranty. Results are virtually indistinguishable from a brand new tub.
Preventing future stains and discoloration
To keep your tub sparkling white for longer after cleaning and refinishing, follow these maintenance tips:
- Rinse the tub after every use to prevent soap scum buildup.
- Squeegee excess water to minimize mineral deposits.
- Open windows or run exhaust fans to lower humidity and discourage mold growth.
- Clean any dirty spots right away instead of letting them set.
- Consider installing a water softener system if you have hard water issues.
- Avoid using dyes, oils, and harsh chemicals in the tub.
- Apply a thin coat of car wax or polish 1-2 times per year to protect the finish.
When to call a pro for fiberglass tub refinishing
While DIY kits and cleaning can go a long way, some cases may require calling in a professional for tub refinishing:
- If the original gelcoat finish is badly worn or damaged beyond simple cleaning.
- If there are large cracks, deep gouges, or chips in the fiberglass.
- If you want an exceptionally smooth, glass-like finish.
- If the tub has extensive rust staining that requires heavy-duty acid washing.
- If the tub is a unique color other than white that needs color-matching.
Professionals have the equipment, supplies, and expertise to address more severe tub damage and staining. For the highest quality results, sometimes it’s worth paying for professional reglazing services.
Conclusion
With some elbow grease and the right cleaning methods, it is often possible to restore a fiberglass tub’s bright white finish. Refinishing kits or professional reglazing can renew the glossy surface if cleaning alone doesn’t do the trick. Maintaining the finish properly after refurbishing will help your tub stay white and prevent stains from returning quickly. With the proper care, your fiberglass tub can maintain its shiny, like-new appearance for years before needing to be refinished again.