Other Tips & Design Ideas

4 Effective Ways to Make a Fiberglass Tub White Again

Written by

Rosanne Jones

Writer, Designer


Steven D. Carrico


how to make a fiberglass tub white again

Bathtubs are a staple in every American home. Having it offers some advantages, as it comes in handy, especially as a water therapy and relaxation. Bathtubs are ideal if you have elderly, kids, and pets because bath time is more manageable.

However, like other fixtures, it’s prone to limescale, rust, and soap scum. But how to make a fiberglass tub white again? Making fiberglass tubs shine again requires hydrogen peroxide, baking soda, white vinegar, lemon, and some commercial tub cleaner.

This article will teach us how to clean a fiberglass shower and tub. Without further ado, let’s dive in!

Ways to Make a Fiberglass Tub White Again

Cleaning your fiberglass tub has multiple ways. The simplest one is to make a homemade fiberglass tub cleaner. However, you can also opt for ready-to-use cleaning agents, like Bar Keeper’s Friend and Soft Scrub.

The methods listed below will help you clean your fiberglass tub without putting your health at risk. It uses items found in every pantry.

Method 1: Using Baking Soda and White Vinegar


One of the easiest DIY cleaning agents to clean a fiberglass shower and tub is using baking soda and white vinegar.

This method is foolproof for stain removal and restore shine to your fiberglass tub.

You will need:

  • Baking soda
  • 2 cups of white vinegar
  • 2 cups of water
  • 2 tbsps of gentle dishwashing soap (you can use Dawn dish soap)
  • 1 pair of rubber gloves


1. Rinse your bathtub or shower floor with water.


2. Cover the bathtub or floor with baking soda.


3. Cover it with old towels or soft cloth.

4. Boil and pour the hot water on the old towels or cloth. Be careful with it. Make sure to cover all the towels or cloth with hot water.


5. Allow the towels or cloth to cool down before you start cleaning. Touch the towels or cloth first. If it’s still too hot, give it more minutes.

6. After it cooled down, start scrubbing the floor using the towels or cloth.


7. Prepare a mixture of 2 cups of white vinegar and 2 cups of water in a microwaveable spray bottle.


8. Add 2 tbsps of gentle dishwashing soap, like Dawn dish soap.


9. If you don’t have a microwaveable spray bottle, you can put it all in a microwaveable container with a lid.

10. Microwave it for two minutes. Take it out and be careful not to burn yourself. If you are using a different container, transfer it to a spray bottle.


11. Spray the bathtub or shower floor until you emptied the bottle.

12. Let it sit for 30 minutes before scrubbing the floor with a nonabrasive brush to remove the tough stains.

13. Rinse with clean water and your bathtub or shower floor is all clean and white again.


Method 2: Using Hydrogen Peroxide and Baking Soda


To whiten a yellowed fiberglass bathtub, you will need hydrogen peroxide. Although this can be a drastic solution, it will help you get a tub white again!

When using hydrogen peroxide, it is best to observe safety precautions before using it as it can cause skin burns when used for a long period.

For this method, you will need:

  • Hydrogen peroxide (3%)
  • baking soda
  • One pair of rubber gloves (necessary)
  • Mixing bowl
  • Whisk or spoon
  • Kitchen towel

Steps to follow:

  1. Put 2 part of hydrogen peroxide (3%) with one part of baking soda in a mixing bowl.
  2. Mix them well until you will achieve a thick paste.
  3. Apply the paste on the stains of your bathtub. Make sure to wear gloves to avoid skin irritation or burns from handling these ingredients.
  4. Leave the paste for 30 to an hour to get the yellow stains out of the fiberglass tub.
  5. Use the kitchen towel to remove the paste.
  6. Rinse with water and repeat if necessary.

Method 3: Using Borax and Lemon Juice


Hard water stains are also prominent on fiberglass tubs. These are brown stains and can be hideous to look at.

To make it go away, you can use borax and lemons. Lemons help in dissolving stains; plus it smells good too! It also acts as a cleaner and polish at the same time, much like using a baking soda paste.

You will need:

  • Borax
  • One lemon
  • One pair of rubber gloves (necessary)

Steps to follow:

  1. Rinse your tub a little. Then, drizzle borax on the hard water stain.
  2. Prepare one lemon and cut it in half.
  3. Wear gloves and start rubbing one-half of the lemon into the borax.
  4. Let it sit for one to two hours.
  5. Rinse with hot or warm water.
  6. If there are still stains, drizzle a baking soda and a drop of gentle dishwashing soap on a wet toothbrush or soft-bristled brush.
  7. Scrub it in a circular motion.
  8. Rinse with water to drain the mixture.
  9. Polish it by using a microfibre rag to eliminate any streaks.

Method 4: Using Ready-to-use Cleaning Agents


When choosing commercial cleaners, make sure it’s safe for your fiberglass tub or shower. Abrasive cleaning agents, like Ajax or bleach, can cause scratches or damage to the tub or shower.

Here are some of the cleaning agents you can use if homemade ones are a tedious task.

  • Soft Scrub – good for fiberglass cleaning
  • Bar Keeper’s Friend – good for porcelain, tile, and fiberglass. It may take one and a half hours of scrubbing.
  • Weiman Tub, Tile, and Fiberglass Cleaner – great for fiberglass as it’s designed specifically for that material

Make sure to read instructions before usage and always wear rubber gloves to avoid skin irritations or burns from using these cleaning agents.

Maintenance and Don’ts With Your Fiberglass Tub and Shower

To prevent a massive build-up of scum, molds, mildew, and hard water stains on your fiberglass tub and shower, you must have weekly upkeep to prevent it from looking dirty.

First, clean your bathtub with one of the methods above. Then use the disinfectant listed below as your weekly upkeep to maintain the cleanliness at all times.

  • You can use hydrogen peroxide as your disinfectant. Just put 100mL of 3% hydrogen peroxide in a spray bottle. Make sure to use rubber gloves before putting it in a spray bottle. Spray it into the tub and wait for 30 minutes before rinsing with water.
  • You can also use baking soda alone. Just sprinkle it and dampen it before leaving it overnight. Rinse it in the morning with hot water. And your tub or shower is all clean!
  • Don’t use hydrogen peroxide on any fiberglass tub because the color will fade away.


If you’re facing a dilemma on how to make a fiberglass tub white again, you don’t need expensive cleaners to do the job. You can turn to your pantry and whip up homemade cleaners.

Baking soda, white vinegar, lemon, Borax, and hydrogen peroxide are the most common items you can use to make DIY cleaning agents. However, always make sure to use rubber gloves when you are handling these items.

Stick to a weekly cleaning schedule to avoid build-ups of soap scum, molds, mildew, and hard water stains. This way, your fiberglass tub or shower is always clean!

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