How to Clean a Fiberglass Sink

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Fiberglass is a strengthened plastic substance that is made of merged material surrounded by glass fibers. It may seem difficult to clean fiberglass, but if done systematically, it’s easy and quick. Let’s see how to clean a fiberglass sink.

How to Clean a Fiberglass Sink

Fiberglass is used to fabricate bathroom accessories like fiberglass sinks, bathtubs, or any other domestic items used for holding liquids. Therefore, it is prone to getting dirty, especially for fiberglass bathroom sinks, and will acquire rigid stains if not regularly cleaned.

Step #1: Use Baking Soda With Warm Water

  • Please use a soft cloth or sponge, dampen it and sprinkle some baking soda over it. 
  • Scrub the fiberglass stains with a sponge or cloth using moderate pressure to scrub and clean hard water stains and dirt, you can also use this baking soda mixture in cleaning copper sinks.
  • Use the other damp cloth to sweep away the baking soda from the fiberglass after scrubbing. Scrub gently to keep the fiberglass finish.
  • If baking soda does not help with the stains, you may use acetone as a last resort. It is safe if you use it sparingly and rub the solvent gently.

Step #2: Use a Mild-Coarse Cleanser

If getting rid of the deeper stains is proving to be a bit troublesome, try a mild abrasive cleaner like Bon Ami, and Brill-Glow. 

With these, you can scrub off any stains without damaging the fiberglass surface. After scrubbing stains, rinse the sink using warm water.

An arm with yellow gloves cleaning a bathroom sink

Step #3: Use Calcium Removers

  • Products like the CLR, Lime-A-way or even 5 percent of white vinegar are safe to use for cleaning fiberglass. 
  • Please do not use this procedure for every week’s wipe-down. 
  • Follow the steps and procedures according to the manufacturer’s instructions and wipe it off with warm water.  

Step #4: Use Oxygen Bleach

Last but not least, if you do not get your desired results by the procedures mentioned above, using oxygen bleach as a last resort sure will. 

You can either purchase or prepare oxygen bleach at home. But ensure to take extra care and all the necessary precautions when using oxygen bleach as too much acid can damage the surface. 

  • Take hydrogen peroxide and baking soda and mix these two in equal amounts with hot water, and it is ready.
  • Now, apply it to the stains only, wait for an hour and let it work and then rinse it away.
  • Once you are done with the cleaning process and the sink is pleasant and shiny, you can add a graded gloss cleaner to your sink. This can increase the shiny appearance of your sink and provides a protective layer against stubborn stains.
Close up shot of a bathroom sink being cleaned

Frequently Asked Questions

How Do Fiberglass Sinks Develop Stains?

Fiberglass sinks can develop stains as they accumulate dirt and grime with consistent usage. Over years of use, it is normal for your fiberglass sink to suffer wear and tear, resulting in a dull appearance.

How to Remove Scratches Out of the Fiberglass Sink?

To remove more scratches from fiberglass, first, clean the sink with a soap water solution. This will help to have a clear view of them and their depth in this composite material. Then, apply some petroleum jelly, and keep rubbing over the scratch. Petroleum jelly is also great for keeping the leather flexible in Jordan 11 shoes.


No wonder fiberglass is one of the lightest and most inexpensive materials available on the market. These are durable, but you can struggle to clean fiberglass, just as you clean stained glasses and hot tubs. That’s because it can get all scratched up if you use the wrong tools and cleaners.