Why Is My Fiberglass Tub Yellow?( Tips)

Why Is My Fiberglass Tub Yellow?

Why Is My Fiberglass Tub Yellow?

The Fiberglass yellowing comes from heat or normal discoloration from extended usage. Also from hard water, knobs and fixtures that rust or corrode after sometime. Still, dirt, soap scum, and other debris build up in some tub regions like where caulking is used.

When your fiberglass tub gets the yellowing color, its eye-catching capabilities will fade into thin air. Once this happens, you will need to strive to regain its cleanliness. And it’s not easy.

While fiberglass tubs are not only popular but also less likely to crack compared to ceramic or porcelain tubs, yellowing can steal the points gained by fiberglass if not addressed well.

Yellow stains are easy to come since everyday use of the bathtub makes it hard to keep them clean and hygienic. Consequently, the dirt and grime make the tub dirtier and messier.

White vinegar has been hailed for its ability to clean fibreglass tubs’ yellow stains.

Usually, white vinegar is known for removing mold, mildew, and yellow stains in the shower, making it perfect for cleaning fiberglass tubs.

To clean your bathtub using white vinegar, get a simple mixture of white vinegar and two-part water to remove the discoloration.

These should be mixed in equal volumes, and the mixture poured into the bathtub. The mixture should be brushed over the bathtub gently and rinsed thoroughly.

Interestingly, this solution will be handy in removing any soap scum or stains from your tub.

Do Acrylic Tubs Turn Yellow?

No, Acrylic tubs do not turn yellow. As you might be aware, acrylic tubs come from the heating and molding on acrylic sheets.

The result is a non-porous material that won’t allow increasing mold and mildew. Therefore, the tub cannot turn yellow like a fiberglass bathtub.

Additionally, acrylic tubs have materials that are inexpensive and shine.

Essentially, acrylic tubs can be correctly referred to as decorated sheets of plastic consisting of fiberglass layers.

These highly durable, lightweight are made through a solid process. Luckily, acrylic bathtubs are durable, lasting up to 30 years and easy to install.

When acrylic bathtubs are made, a solid sheet of Acrylic is heated until it’s pliable. After this, it’s stretched over a mold.

When curing the plastic material, the shape of the tube needs to pull out of the mold.

While this is the basic procedure, modern technology has made it possible to make more durable acrylic tubs, adding extra layers that need to be sealed to ensure shine and protection.

This makes acrylic more durable and far better than fiberglass.

How Do You Deep Clean A Fiberglass Tub?

Although fiberglass tubs are vulnerable to scratches, you can keep your tub looking clean easily if you use the right cleaning products. It’s easy to keep your tub looking clean.

Indeed, it’s not hard to get rid of tough stains on your fiberglass bathtub without scratching. There are several steps to follow to deep clean a fiberglass bathtub.

You will start by mixing 1 quart of warm water with ½ cup (of detergent. Alternatively, use a liquid laundry detergent or a dishwashing detergent.

These ingredients need to be mixed until they are well combined. But you will want to avoid abrasive cleansers like scouring powders.

Continue by rinsing the tub with water using a bucket or a pitcher. However, all the surfaces you want to clean should be clean and wet.

Why Is My Fiberglass Tub Yellow?

But if your showerhead is removable, use it to rinse your tub.

The solution should be applied with a sponge, using a circular motion when scrubbing the tub with your sponge. On small crevices, you can use a toothbrush.

All in all, you will remember that gentle applicator like sponges, cloths, and polyester/polyethylene scrub brushes. If you use abrasive applicators, your fiberglass tub will be scratched.

After this, your tub should be rinsed gently, removing all traces of residue and soap.

To get the best from this, it might be needful to rinse three to five times. This can be followed by drying your tub with a dry soft towel.

Why Is There Black Stuff In My Bathtub?

This is a fairly common problem resulting from rubber parts’ deterioration.

Rubber parts in your bathtub can deteriorate due to chloramine treatment carried out by the water company.

The affected parts are washers in faucets, flexible hoses at the water heater or below the sink, or shutoff valves under the sink.

Another cause of black stuff in your bathtub is magnesium sulfide from water reacting to magnesium anode. Generally, this is more common with soft water than with hard water.

Still, galvanized pipes can corrode due to manganese in water, causing the black stuff in your bathtub. Fortunately, this will not be common with city water.

One sure way to know if the problem is from the city water is to find out if your neighbors are experiencing the same problems. If so, you can be sure that this is the city water problem.

Some homeowners argue that the greasy black stains come from the black rubber drain gasket when it starts eroding, producing a thick, black paste!

If this is the case, it must be rubbed to clean. Therefore, replacing the bathtub rubber plug thingy can bring some desired results.

Why Do Fiberglass Bathtubs Crack?

Your popular fiberglass bathtub is not indispensable when it comes to cracking. Cracking is one thing that makes your inexpensive choice for a bathtub worth a second thought.

Indeed, a few years of use may remove the glean that your fiberglass bathtub had, in addition to getting a few cracks.

Ideally, cracks come from several causes, including improper installation, heavy objects, and harsh cleaners.

As you know, fiberglass is flexible and easily bends when weight is placed on it. Therefore, your tub will need adequate support to withstand frequent use.

Improper installation of your bathtub will result in cracks on your fiberglass.

On the other hand, heavy objects will cause cracks in your fiberglass bathtub. Your fiberglass bathtub can receive nicks and cracks if heavy objects are dropped.

Cracks can form if children drop heavy objects. It’s unlikely for shampoo bottles to cause any significant damage when dropped

Still, harsh cleaners cause problems on your glass bathtub. Using harsh cleaners can make your tub lose its gloss even as they weaken the surface.

I recommend using a gentle bathroom cleaner that can sit on the surface for five minutes before being cleaned with a washcloth.

Although cracking in your fiberglass bathtub is something you do not want to see, you don’t have to break your bank on buying a replacement tub.

It’s possible to get appropriate repairs at a fraction of the cost, in addition to getting tips on how to take care of your fiberglass bathtub.

Most cracks can be fixed and the surface of your bathtub revitalized.

How Do You Fix A Hairline Crack In A Fiberglass Tub?

Hairline cracks in a fiberglass tub can be fixed easily. The procedure to use when fixing a hairline crack in a fiberglass tub is the same you use on your acrylic bathtub.

But before I take you through the process, let me mention that frequent use is a common denominator when it comes to the causes of a hairline crack on your fiberglass tub.

Additionally, insufficient support, dropping the tub, using harsh cleaners, and hitting the tub with heavy objects lead to hairline cracks.

Unless you fix this on time, these otherwise small cracks will develop into larger cracks, resulting in leaks and eventually, your bathtub might even break apart.

To clean a hairline crack on your tub, start cleaning and drying the cracked area before you sand it with a fine-grit sandpaper.

This will be followed by applying an adhesive on the crack before applying a fiberglass filler.

After this, sand the area again before applying an epoxy mixture and a piece of fiberglass clothing.

Before you can apply a sealer to fix a hairline crack in your fiberglass tub, it’s recommended to apply more epoxy mixture.

Alternatively, use a household cleaner to clean the cracked area and remove any dirt, mold, or other debris. Use a sponge to scrub the area before rinsing it with clean water.

Continue by sanding the area and then applying the adhesive.

Does Acetone Dissolve Fiberglass Resin?

Yes, Acetone dissolves fiberglass resin.

However, you can only add a maximum of 10% to the resin, being a thick fiberglass liquid becomes a solid when mixed with an extra percentage catalyst;

You need not exceed the 10% threshold if you desire favorable results. Indeed, you can even thin epoxy resin with acetone.

However, as you use acetone or paint thinner to thin epoxy, you must remember the general rule of thumb (a maximum of 10% added to the epoxy resin).

If, in the process, you find that you want to remove hardened fiberglass resin, you will need to first heat the fiberglass along with one of the edges before gently forcing a chisel or a putty knife under the fiberglass.

After an edge is lifted, gently pull up on the fiberglass using a pair of pliers.

One hand should pull on the fiberglass as you continue to heat the resin and fiberglass with a heat gun in your other hand.

But if you want to thin out the resin, mix in thinner at a ratio of 10 to one. This means that 10 gallons of epoxy resin would require one gallon of paint thinner or acetone.

But you will always need to remember that adding too much hardener will impact the chemical reaction, and the mixture will not cure properly.

Is CLR Safe For Fiberglass Tubs?

Yes, CLR is safe for fiberglass tubs.

CLR is not just for bathtubs but a multipurpose, multi-surface cleaner that takes on calcium, soap buildup, lime, and dirt on sinks, showers, toilets, and fiberglass tubs, tiles, chrome fixtures and stainless steel.

Indeed, CLR is the right product for any kitchen or bath cleaning task.

As you might be aware, nobody likes to take a bath in a filthy tub as you won’t get clean that way.

Luckily, cleaning your bathtub with CLR monthly keeps built-up tub scum out of your soak.

To use CLR in your fiberglass tub, start with a mixture of CLR and water and then progress to full strength, depending on the need.

Additionally, CLR is a fast and effective way of cleaning away calcium and lime deposits and scales from glassware, porcelain, chrome, stainless steel, fiberglass, and grout.

Still, you can safely use CLR on all PVC and copper plumbing.

CLR is very effective and safe. I think the best way to explain this is to compare it with a well-known product like vinegar.

If you compare CLR with vinegar, you will agree that CLR might be about 15 times more effective than vinegar (based on their pH comparison and the acid concentration).

This is to say that 1 cup of pure CLR is as effective as a whole gallon of vinegar.

Can You Mix Oxiclean And Dawn Dish Soap?

Oxiclean should not be mixed with dawn dishwashing soap or any other chemical. Mixing OxiCLean with other chemicals can be counterproductive.

This includes ammonia, dishwashing soap, chlorine bleach, and other household chemicals. This can be used as a general rule of thumb.

The only instance where you can use Oxiclean mixed with other chemicals is when the manufacturer says it is okay to mix the two.

So unless the label says so, it isn’t safe to mix the two.

However, this does not apply to our current definition; it’s never a good idea to mix any cleaning chemicals unless you’re 100 percent sure they can be mixed—as in, the manufacturer says that on the label.

When using Oxiclean to clean, it’s essential to note that you might not get the best results the first time. Yes, Oxiclean might not be entirely successful the first time.

You will appreciate that some stains will always need repeated or longer treatments. So you will have to try again.

After rinsing the fabric or the fabric with clean water, give it another trial with an OxiClean soak to see if the stain improves.

Also, you are expected to rinse Oxiclean surfaces before allowing them to dry.

Can You Use Comet Cleaner On Fiberglass?

Yes,While most non-abrasive and non-aerosol bathroom cleaners can be used on fiberglass, it’s  not safe to use abrasive cleaners, Soft Scrub, or Ajax as they can cause significant damage to the tub liner.

And because Comet is an all-purpose cleaner, it can be used as it also deodorizes porcelain, stainless steel, solid surfaces, fiberglass, Corian, natural marble, and ceramic tile.

The advantage of using a comet is that it does all this without leaving a scratch.

So, if you wish to clean and deodorize your fiberglass using Comet, you need to sprinkle Comet on the wet surface or a sponge and allow it to sit for 15 seconds before rinsing and rubbing.

Why Is My Fiberglass Tub Yellow?

Use a shower cleaner to spray one wall at a time and then sprinkle it with Comet.

A scrubby sponge or scrub brush will be handy to wash the shower floor until the grime, dirt, and soap scum disappear.

The cleaning agent must then be washed down the drain and a dry towel to wipe.

You might need to know that Comet kills 99.9% of germs. This is great as Comet is known for its effective capability to dissolve soap scum and hard water film.

It will also effectively disinfect and clean away the tough stains.

Can You Clean Porcelain With Acetone?

Yes, Acetone can spot-treat specific areas on a porcelain surface before cleaning the entire tub. As you know, porcelain tubs will develop mineral stains over time.

These come from hard water or knobs and fixtures that rust or corrode after sometime. Still, dirt, soap scum, and other debris build up in some tub regions like where caulking is used.

Acetone comes in handy to spot-treat such areas and removes soap-scum buildup and stains. But before you apply any bonding or refining coats, you can wipe acetone over the entire tub.

Using warm water, use a dampened rag to wipe the tub and remove debris or other buildup layered on top of your porcelain surface.

Continue and wipe the tub using a dry rag to remove any additional moisture.

The next thing to do will be to dampen another rag with a small amount of acetone and then place the rag over an open acetone bottle;

Holding it firmly in place and quickly tipping it upside down and back. This will dampen the rag.

To wipe the entire tub, the rag can be placed in the sink and acetone poured on it till the dampening of the entire rag.

Lastly, use acetone to rub the dampened rag over the spot on the tub. Do not be hasty, but allow the acetone to dry as you establish if the spot is lightening.

This needs to be repeated until the stain disappears.

Does CLR Remove Rust?

Yes, CLR removes rust. Rust left alone on metal will have the metal eventually corrode and crumble.

Luckily, CLR — a calcium, lime and rust remover, easily dissolves most rust from metal surfaces.

The metal should then be kept clean and dry, or a rust protector should be applied. This prevents future rusting.

To remove rust using CLR, you must wear rubber cleaning gloves and turn off the water supply to the toilet. After this, flush the water from the bowl and pour 1 cup of CLR.

Let it sit for two minutes before scrubbing the bowl using a toilet brush to loosen the soil. Proceed to turn the water supply back on and flush your toilet.


Yellowing of fiberglass results from overheating and can be controlled easily.


Hi! I' am Tom. I was a manager in one of the biggest stores for over 10 Years, am also an SEO by night. I don't like to call myself a blogger; they are very analytical, do email marketing, and know all SEO stuff. I faced many questions from customers about different products, and there was hardly any help on the internet. After learning all the things about these products as a manager the hard way, I decided to start a blog and help other people.

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