How to Clean a Fiberglass Sink

For people who have never cleaned fiberglass before, the task can seem intimidating. Fiberglass is a highly durable material that is popular for bathtubs, sinks and other basins that hold liquid and act as a receptacle for dishes and other household items that need to be cleaned. However, cleaning fiberglass is a relatively simple task, even when the fiberglass is stained. It requires some time, effort and the right materials.

Detail of a white rectangular designer kitchen sink with chrome water tap against a tiled wall
credit: brizmaker/iStock/GettyImages
For people who have never cleaned fiberglass before, the task can seem intimidating.

How Fiberglass Sinks Develop Stains

When used heavily and consistently, a fiberglass sink is likely to accrue stains over time. This is especially true when the fiberglass sink is being used in a place where there is hard water. Hard water can build up limescale, calcium spots and even rust on the surface of a fiberglass sink. Whether you are using the fiberglass sink in a home kitchen, a commercial kitchen or a laundry station, you will eventually want to clean these stains.

Over years of use, the fiberglass sink can suffer significant wear and tear, making it look dull and overused. Especially when the sink is in the kitchen of your home, you will want to make sure it looks presentable, clean and bright. Typically, people clean the surface of their fiberglass sinks with soap and water, the same formulas that they use to clean their dishes.

Soap and water cleaning is a sufficient solution to remove superficial stains, dirt and liquids. However, to get at the deeper stains, soap scum and mineral residue, you'll need to employ the power of additional and more abrasive household products.

Do You Need Fiberglass Cleaner?

While there are several high-quality dedicated fiberglass cleaner products on the market, purchasing a product specifically designed to clean fiberglass is not at all necessary. You can get rid of stains on a fiberglass farmhouse sink or a fiberglass bathtub with simple household materials that almost everyone has on hand.

The key to cleaning fiberglass stains is to remove the stain without scratching the surface of the sink or the tub. This is especially critical if your fiberglass has a color besides white, as scratching a colored fiberglass surface will make the scratches significantly more visible than they would be on a white surface.

Begin by washing the surface of your fiberglass farmhouse sink, tub or basin. Use hot water, a sponge and a strong enzymatic dishwashing soap. Once you've completed this process, you can move on to the more abrasive products in your cleaning arsenal. However, you should never use steel wool on fiberglass. It can scratch and etch the surface creating an unsightly appearance in addition to small striations where bacteria can hide and multiply.

Removing Fiberglass Stains

While the sink is still wet from your initial cleaning, sprinkle a generous portion of baking soda onto the surface of the sink. Spread the baking soda across the surface of the sink with a soft cloth dipped in warm water. Move the cloth in circular motions, applying heavier pressure to the stained areas. The alkaline properties of the baking soda should help break up any lingering stains, grime or mildew without scratching the fiberglass.

Once you've scrubbed the stains with baking soda, you can rinse the surface of the sink with hot water, removing any remaining baking soda. Ideally, this will clear the surface of the sink of all remaining debris. If there are still stains remaining, repeat the process with the baking soda. If several rounds of baking soda do not eliminate the stains, you can simply purchase a fiberglass stain remover and see if that does the trick. If baking soda doesn't get the stain out, acetone on fiberglass is safe as long as you use sparingly and rub the solvent gently to keep from eroding the fiberglass finish.

Once you've removed the stains and cleaned the fiberglass to a pleasant shine, it's a good idea to apply a commercial-grade gloss cleaner to the surface. This will increase the fiberglass shine and provide a protective coating that will go a long way toward preventing future stains.


Ashley Friedman

Ashley Friedman

Ashley Friedman is a freelance writer with experience working in the home, design and interiors space.