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The Daily Insight

How do you whiten yellowed fiberglass?

Author

Christopher Snyder

Updated on February 27, 2026

Fiberglass bathtubs may start to turn a yellowish color as a result of soap scum or hard water. These stains can be very difficult to remove. However, a mixture of cream of tartar and hydrogen peroxide will easily remove any stain and restore the tub to its original white color.

How do you fix yellow fiberglass?

Use a fiberglass cleaner and restorer like Boat Scrub to remove stains and yellowing of your fiber glass boat. We recommend using a Marine Power Mitt to reduce your labour and cleaning time. Add protection from UV and dirt to your fiber glass boat by applying Premium Boat Shine.

How do you whiten yellowed fiberglass shower stalls?

Combine baking soda and water to create a paste similar in consistency to toothpaste. Rub the paste over the yellowed surround. Allow it to set for up to one hour.

How do you restore white fiberglass?

Quickly restore shine to fiberglass while cleaning away mildew and grime using vinegar. Vinegar is a slightly acidic solution that breaks down crud and dirt while leaving a streak-free shine. In this case, the recipe calls for a combination of vinegar and cleaning with baking soda.

How do you brighten fiberglass?

White distilled vinegar.

Spray the vinegar full-strength on the stains; let it stay there for a few minutes, and then scrub it off. Acetone or turpentine. Wipe these solvents on the plastic with a soft cloth to remove stains caused by dye, paint or pigments.

How to whiten yellowed plastics (cheap & easy!)

Can you use OxiClean on fiberglass?

It will also clean most stains on fiberglass, teak, and sails. I love this stuff. OxiClean does not ruin clothes when used properly.

Does vinegar dissolve fiberglass?

Does vinegar dissolve fiberglass? Vinegar is a safe alternative to harmful chemicals. The best way to remove fiberglass fibers is by first taking a hot shower first, then rinsing off the area with vinegar. Then, rinse again with cold water to remove the vinegar's odor.

Will bleach hurt fiberglass?

You can clean a boat with bleach, but it does contain very harsh chemicals and over time can damage gel coats on fiberglass boats, degrade vinyl seating threads, vinyl boat wraps, discolor and fade paint, and lead to corrosion in boat fittings and fixtures.

Does bleach break down fiberglass?

Bleach can also damage fiberglass, so verify that it's not an active ingredient in your mild cleaner. You can also make a homemade cleaner easily by combining vinegar with regular dish detergent. This cleaner may work particularly well in showers.

Can you use acetone to clean fiberglass?

There are several products you can use to clean fiberglass, including acetone--a chemical that is also used to remove nail polish and other paints. Acetone removes not only dirt and grime from your fiberglass surfaces, but also any set-in stains like rust and pen marks.

Will Magic Eraser damage fiberglass shower?

Spray and clean with a sponge, and save the balance to clean mirrors, windows and appliances. Some people insist that there's no better method for cleaning your fiberglass shower than to use a magic eraser. They recommend that you use an oven cleaner with the magic eraser.

How do you make yellow plastic white again?

Using Peroxide to Clean Yellowed Plastic

  1. Pour straight peroxide in a container.
  2. Put the plastic in the container.
  3. Allow the plastic to soak in the sunlight until the stain lifts.
  4. Rinse and dry.

How do you clean a discolored fiberglass tub?

Before you give up on trying to scrub away the stains, try the cleaning process Home Depot recommends for tough stains on fiberglass: Smear on a paste of baking soda and water, and cover that with a towel soaked in vinegar. Wait one hour, then rub with a cloth or sponge. Rinse. Wipe again with a clean microfiber cloth.

What is the best product to clean fiberglass tubs?

Start with Good Old Dish Soap

If you are looking for a basic bathtub cleaner, one of the best places to start is with a mild soap and water solution. Either dish soap or laundry detergent is an excellent resource when it comes to removing grime and grease. Both should be fragrance-free without any bleaching agents.

Can you use magic eraser on boats?

You can use Magic Eraser on vinyl floors, vinyl siding, and vinyl boats seats, and get amazing results as shown in the photo above. For example, in high traffic areas on your boat such as walkways and decks, you're going to get a lot of muddy footprints, dirt, grease, and more nasty stuff.

Can you use brake cleaner on fiberglass?

It may be the best for a metal Airstream but NOT for a fiberglass trailer as you could damage the gelcoat due to the various ingredients found in brake cleaner. Its not meant to touch any plastics or paint.

Can you use rubbing alcohol to clean fiberglass?

Bleach, however, should be avoided in cleaning fiberglass because it can attack the resin structure of that material. For polycarbonates, disinfectants containing hydrogen peroxide or isopropyl alcohol (also known as: isopropanol or 2-Propanol) have shown to be compatible.

Can I use 409 on fiberglass?

To avoid scratches and surface problems in the future, never use abrasive cleansers or strong chemical solutions on your fiberglass fixtures. Use bathrooms cleaners like 409, Fantastik or Comet's Bathroom Cleaner (without bleach).

How do you clean fiberglass?

To clean fiberglass dust and debris from surfaces, use wet mops and cloths or a vacuum cleaner equipped with a HEPA filter. Do not dry sweep or perform other activities that may stir up dust.

Is fiberglass A asbestos?

Asbestos is naturally occurring, while fiberglass is human-made. Asbestos has always been naturally present in some soils and rocks. Fiberglass began being commercially synthesized from glass silica compounds in the 1930s. Both substances have thin fibers, but one is human-made.