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8 Affordable Solutions on How to Whiten Yellowed Fiberglass

I know how embarrassing it is when a guest comes over and sees your yellowish fiberglass. Well, it doesn’t give a good impression of yourself. But don’t be anxious. You can fix it on your own!

How to whiten yellowed fiberglass?

A blend of water with inexpensive cleaning ingredients like vinegar or lemon can effectively erase any stain. You can also use baking soda, salt or shampoo for this. Pour the mixture over the fiberglass and wait 15 minutes to erase tough stains. After massaging the affected area, rinse the glass.  

To fully whiten yellowed fiberglass, you’ll need to learn more. So, in this manual, I’ve addressed all the solutions.

Hang tight for additional information!

8 Easy Solutions to Remove Stubborn Yellowed Fiberglass

Fiberglass is especially popular because of its low cost and durability. Fiberglass bathtubs or shower stalls are less prone to breakage than porcelain tiles.

But you need to worry about one minor issue: yellowing.

The fiberglass surface will begin to crack and leak with duration. It will start getting yellow as a result of heat or extensive usage.

Keeping clean and hygienic fiberglass is tough. Otherwise, the fiberglass will appear dirty, cluttered, and yellowed.

So, I have mentioned some easy methods and the ingredients can be found easily. You can use similar methods to remove spots from fiberglass doors.

Solution 1: Lemon

Many people use toilet disinfectants to clean fiberglass. But this option can be expensive. 

Lemons are relatively inexpensive, making them a cost-effective option.

You may slowly pour lemon on the filthy fiberglass. 

The acidic nature of lemon cleans the fiberglass and also restores its luster at the same time. Lemons have several beneficial attributes that help with the cleaning process. 

You can disinfect the fiberglass without using pollutants. The pH level of the lemons will protect your fiberglass from becoming yellowish again.

After that, you may brush it to get rid of the spots on the napkin. After you’ve removed all of the areas, wash the extra lemon juice away with warm water.

Solution 2: Vinegar

White vinegar is fantastic for cleaning fiberglass. It dissolves mold, bacteria, and yellowish discoloration in the shower.

Your bathroom’s fiberglass tub may be filthy and murky.

To erase the staining, all required is a simple combination. One is white vinegar and the other one is water.

Slowly pour the mixture into the bathtub. Spray the vinegar mixture lightly over the surface before thoroughly rinsing. This remedy will clean your tub of any dirt and grime, or spots.

Vinegar is a really handy substance when it comes to cleaning. In fact, cleaning your stove top also can be done with the help of vinegar.

Solution 3: Baking soda

Baking soda is an excellent cleaning agent. Ithas a mild exfoliating quality that might help you erase stubborn stains and grime from your fiberglass.

Mix 3 tablespoons of baking soda and ½ cup of water. Then, scrub the tub with the mixture. After you’ve washed the place, wash it with water to make sure it’s clean.

Solution 4: Salt

Old yellowed fiberglass may be cleaned by mixing salt with water. Stir the salt and water together and put them into the fiberglass. 

Then scrub the spot with a brush until all yellow areas have vanished. After that, properly clean the fiberglass with warm water to eliminate any salt remains. 

And you will see that your outdated fiberglass will appear like a new one.

Solution 5: Shampooing

Yes, shampoo can clean a yellowed fiberglass tub. I know you must be surprised to hear that. But well, it can clean fiberglass tubs and sinks. 

First, drop some shampoo over the fiberglass. Then, scrub it with a sponge until it sparkles and is spotless. Then wash it gently with water until no shampoo remains.

Solution 6: Soft Drinks 

Soft drinks may be used to clean a fiberglass tub, something most people are unaware of. But, It is a very efficient and cost-friendly method.

Soda will assist you in removing the tub’s yellow tint. And leave it literally gleaming clean afterward. It is, without a doubt, an excellent method for erasing stains from fiberglass.

Coca-Cola and Pepsi are two soft drinks that might transform your tub. 

First, fill the tub with your favorite beverage and set it aside for 10 minutes. After that, carefully massage the spots with a brush. The sugary ingredient in the drink will aid in the removal of stains. 

After that, please give it a wash before relaxing in your sparkling new fiberglass.

Solution 5: Cleaner Made with Chemicals

To remove stains from fiberglass, you can use a chemical cleaner as an alternative. It aids in the removal of discoloration that seems yellow or brown. 

Carbon tetrachloride, carborundum or caustic soda can be used as chemical cleansers.

Pour the product into your glass first and set it aside for 5 minutes. This allows the solution to soak in and penetrate the spots thoroughly. You should scrape the stains on your fiberglass with a brush after 5 minutes.

These items are both safe and straightforward to use. You’ll be able to clean your bathtub effectively if you carefully follow these directions:

Product 1
Product 2

Hopefully, the suggested items will assist you in your task.

Yellowed fiberglass represents that you are unattentive towards cleaning. Well, we both know that’s not the case. By applying the following methods, avoid embarrassment.

Solution 6: Hydrogen Peroxide (H2O2)

Hydrogen peroxide is usually used to whiten teeth and is often found in wipes. But it may also be used to clean and sterilize bathroom items. 

Hydrogen peroxide and water may work wonders on a yellowed fiberglass shower tub. 

First, mix some hydrogen peroxide with water and pour all over the fiberglass. Then scrub the tub’s walls clean. Finally, clean the tub with water. 

We highly encourage you to wear protective equipment such as goggles and gloves. When using this liquid since it may cause temporary blindness and skin irritation.

Prevention Methods to Avoid Yellow Discoloration of Fiberglass

There are some pretty easy hacks you can apply to avoid yellow stains of fiberglass. I have mentioned the 3 most effective hacks here. 

Let’s have a look.  

Hack 1: Use It Properly

Preserve the color of your fiberglass. Never use the fiberglass tub as a pond or aquarium with water and bugs.

You may not think you’ve harmed the glass, but it may discolor with time. It may potentially cause damage. So, be very careful.

Hack 2: Check the Airflow

Keep the fiberglass as dry as possible. Wet mineral deposits in bathtubs and sinks cause discoloration. 

But proper ventilation may help. Ensure the area around the tub is well ventilated to minimize discoloration or rusting.

Hack 3: Clean it up

Food, bath crayons, and shampoo stains are a few examples. Be sure to keep your fiberglass clean. 

Fiberglass is a minimal, low-maintenance solution for any bath remodeling project. These fiberglasses might get bland and yellowed if ignored and not maintained correctly. So, maintain a regular cleaning routine.

Cleaning Linoleum isn’t an exception and needs to be taken care of similarly.


Question: How do you restore a yellowed fiberglass boat?

Answer: Use a fiberglass cleaner and restoration like Boat Scrub to remove stains. We recommend using our mentioned methods to save effort and cleaning time. Protect your fiberglass boat from UV and for better results use cleaning chemicals.

Question: How do you clean exterior fiberglass?

Answer: Cleaning fiberglass exterior doors with a mixture of white vinegar is ideal. Gently apply on the door with a soft wet sponge. To erase tough stains, use a soft-bristle scrubbing brush.

Question: Does baking soda scratch fiberglass?

Answer: Baking soda, non-abrasive detergents, and all-purpose cleaners are great options. Do not use abrasive cleaning chemicals like scouring powders. It might damage your fiberglass tub or shower.

Bottom Line

There you have it, all of the information I had on how to whiten yellowed fiberglass. 

You prevent any kind of trouble, be sure to adhere to all of the techniques listed above. However, if the issue persists after you’ve tried everything, you should see an expert.

Best of luck to whiten your yellow fiberglass!