How to Clean a Fiberglass Tub

Co-authored by Michelle Driscoll, MPH

Last Updated: December 17, 2022

Fiberglass tubs can be vulnerable to scratches, but if you use the right cleaning products, it's easy to keep your tub looking clean. We'll even show you how to get tough stains out of a fiberglass tub without scratching, so keep reading!

Method 1

Method 1 of 3:

Using Detergent

1
Mix 1 quart (0.95 liters) of warm water with ½ cup (125 mL) of detergent. You can use a dishwashing or liquid laundry detergent. Mix the ingredients together until they are well combined.^{[1]
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- Avoid abrasive cleansers like scouring powders.
2
Rinse the tub with water. Use a bucket or a pitcher to rinse your tub. Make sure all of the surfaces that you want to clean are wet.
- Alternatively, if you have a removable shower head, then you may use this to rinse your tub.
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3
Apply the solution with a sponge. Use a circular motion to scrub the tub with the sponge. You can use a toothbrush to clean small crevices.
- Make sure to use gentle applicators like sponges, cloths, and scrub brushes made from polyester, polyethylene, or nylon. Abrasive applicators like steel wool and scouring pads will scratch your fiberglass tub.
4
Rinse the tub thoroughly. Use a bucket or a showerhead to remove all traces of residue and soap. You may need to rinse your bathtub three to five times.^{[2]
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5
Dry the tub with a towel. This way you can prevent water from pooling in the corners and crevices of your tub. Pooling can cause mildew, mold, and bacteria to grow.^{[3]
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- Drying the tub will also prep it for polishing, if you choose to polish your tub.

Method 2

Method 2 of 3:

Cleaning with Baking Soda

1
Mix 3 parts baking soda to 1 part water to form a paste. Make sure the paste is thick, similar to the consistency of toothpaste. You want the paste thick enough so that it can stick to the sides of your tub.^{[4]
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- For extra cleaning power, add in 2–3 tablespoons (30–44 mL) of vinegar.
- If your paste is thin, then just add more baking soda until it forms a thick paste.
2
Apply the paste with a sponge. Apply the paste to both the sides and bottom of the tub. Then let the paste set for 30 minutes.^{[5]
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- Depending on how dirty your tub is, you may need to let the paste set for a longer amount of time, like an hour or so.
3
Scrub the paste off. Do this once the paste has set for the allotted time. Use a nylon brush to scrub the paste off to avoid scratching your tub.^{[6]
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4
Rinse the bathtub with water. Using a bucket or a showerhead, make sure to rinse it thoroughly until the residue is gone. Then dry your tub with a clean towel.^{[7]
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5
Remove tough stains with nail polish remover. Dip a cotton ball or a clean, white cloth in the nail polish remover. Gently rub the tough stains individually until they are gone. Wipe the areas with a clean, wet cloth, and then dry them with a clean towel.
- Alternatively, you can use turpentine to remove tough stains.
- Because these solvents are highly flammable, do not use them near open flames or heat, and make sure the area is well-ventilated.

Method 3

Method 3 of 3:

Polishing Your Fiberglass Tub

1
Apply a marine-grade rubbing compound with a soft cloth. Working in small sections, apply the compound onto the sides of your tub, paying special attention to dull spots and scratches.^{[8]
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- Do not focus on one area for too long. The compound may burn the fiberglass if you do.
- You can purchase the marine-grade compound from your local hardware or automotive store, as well as online.
2
Buff each section with a terry cloth. Do this right after applying the compound. Using a circular motion, rub the sections with the cloth to buff them.^{[9]
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Apply a car wax in small sections with a soft cloth. Any type of car wax will work, however, apply the wax per the instructions on the bottle. Make sure the wax gets inside small crevices in the tub.^{[10]
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- Try to avoid applying wax onto the bottom of your tub. The wax will make your tub very slippery. If you do use wax on the bottom of your tub, make sure to place a bathmat in the tub afterwards to avoid slipping.
4
Rub the sections with a terry cloth in a circular motion. This will buff the wax. Rub the sections until all of the wax is removed and the surface shines.^{[11]
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Rinse the tub with cold water. Use a bucket or a showerhead to do this. Rinse your tub 2 to 3 times. Then, dry it with a clean towel.^{[12]
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- Make sure to use cold water so the wax will harden.
- It is recommended that you polish your fiberglass tub twice a year.

Expert Q&A

Question

I have always waxed my fiberglass shower/tub for years. Used Maguires Ultimate Paste Wax and now it has a nasty feel to it. How do I get rid of it? Thanks.

Michelle Driscoll, MPH
Founder, Mulberry Maids
Michelle Driscoll is the Owner of Mulberry Maids, which is based in Fort Collins, Colorado. With five years of experience, her business specializes in cleaning homes and small offices. She holds a Masters in Public Health from the Colorado School of Public Health. Additionally, Mulberry Maids has an A+ rating from the Better Business Bureau.

Michelle Driscoll, MPH

Founder, Mulberry Maids

Expert Answer

If you have already tried to clean the tub using baking soda or detergent, you can try to apply nail polish remover or turpentine to the areas in question. Apply the nail polish remover or turpentine with a clean cloth, gently scrubbing the area. Follow this by wiping the area with a wet cloth, and dry with a towel.