The fiberglass hull of your boat is the most exposed to the harsh elements while on the water, so you’ll notice how much faster they succumb to wear and tear compared to the other parts of your boat.
Knowing how to clean boat hull fiberglass yourself would not only save you some money, but it will also help you keep your boat in top shape. However, with the many options for cleaners out there, how will you know which one is the best cleaner for fiberglass boat?
Choosing the right cleaner for your boat is important because fiberglass is a delicate surface, especially with its gelcoat.
Using the wrong type of cleaner might end up damaging your boat’s exterior more than restore it as you intended.
Considering this, I listed and compiled some of the best fiberglass cleaners on the market listing their features, pros, and cons.
Aside from a product review, I also created a comprehensive guide to help you select which one is the best for fiberglass boat cleaning.
Table of Contents
Best Cleaner for Fiberglass Boat Reviews in 2021
1. MEGUIAR’S M4965 Marine/RV Fiberglass Restoration System
Unlike the other products on this list, the MEGUIAR’S M4965 Marine/RV Fiberglass Restoration System is a 3-step system that cleans, polishes, and restores your boat’s fiberglass hull and ensures that your boat remains sparkling clean.
What I like about the MEGUIAR’S M4965 Marine/RV Fiberglass Restoration System is that it has a complete and thorough process that not only cleans your boat’s fiberglass but also protects it from further or future damages.
It has three parts:
- the Oxidation Remover which is great at removing oxidation stains and things like scratches from your fiberglass boat
- the High Gloss Polish which restores your boat’s exterior and helps it shine
- the Pure Wax provides an additional layer of a long-lasting protection that will help you avoid damages to your boat’s exterior and keep it looking pristine.
The MEGUIAR’S M4965 Marine/RV Fiberglass Restoration System is all you need to keep your boat looking amazing and show worthy.
2. Star Brite Ultimate Fiberglass Stain Remover
First on my list of best cleaners for fiberglass boats is the Star Brite Ultimate Fiberglass Stain Remover, a cleaner whose gel-like consistency makes it great for cleaning both vertical and horizontal surfaces.
What I liked about the Star Brite Ultimate Fiberglass Stain Remover is that its gel-like nature allows it to stick onto where it is sprayed, which enables it to “cling” longer.
This allows it to permeate the stain, making it effective and thorough at cleaning with no heavy scrubbing.
It is formulated without the use of dangerous, caustic acids, which makes it safe for use on all fiberglass surfaces.
I also like that it can even be used on other delicate surfaces such as painted ones, rubber, plastic, and vinyl.
I also love how I could use it at home, not just my boat. Being able to do so makes it a great value for money because it’s not only for marine use.
3. Davis Instruments FSR Fiberglass Stain Remover
If you’re looking for a fiberglass cleaner whose specialty is removing exhaust and waterline stains, oil, and rust, then the Davis Instruments FSR Fiberglass Stain Remover is the one for you.
The Davis Instruments Fiberglass Stain Remover or FSR is not only great for those unsightly exhaust and waterline stains but also for removing rust on railings and stainless-steel foundations.
It also works well if you want to remove road dirt from your trailer boat.
What I like about the Davis Instruments FSR Fiberglass Stain Remover is that its stain-absorbing gel formula is non-abrasive, so it is safe for use not only on fiberglass but also on white-painted surfaces and gelcoats.
Its quick-acting nature also makes it easy to use since it removes stains chemically and requires no scrubbing. All you need to do is brush on your desired spot, then wait until the stain is gone.
4. 3M 09009 Marine Cleaner and Wax
Fiberglass boat restoring has never been easier or more convenient with the 3M Marine Cleaner and Wax whose special liquid formula enables you to rid your boat of light to medium oxidation by combining a compound with several special waxes.
Besides oxidation, the 3M Marine Cleaner and Wax also remove filmy residue, exhaust stains, rust deposits, and dock skid marks.
I love the 3M Marine Cleaner and Wax because it not only cleans the fiberglass hull of my boat, but it also polishes and restores its color and shine. With the 3M Marine Cleaner and Wax, you get a cleaner and wax in just one bottle.
This is a convenient way to clean and detail your boat’s fiberglass hull without spending too much time doing so. Because of this, you get to spend more time on your boat than under it.
I also like how its special formula limits and helps protect against UV rays, preserving your boat’s appearance even when exposed to the harsh weather.
You can even use it on surfaces other than your boat’s like your RV or even your car. The versatility and usefulness of this cleaner and wax combo make it a great fiberglass cleaner.
5. Collinite Fiberglass Boat Cleaner
Prepping your fiberglass boat for a good waxing has never been easier with the Collinite Fiberglass Boat Cleaner.
Using strong cleaning agents, the Collinite Fiberglass Boat Cleaner effectively and thoroughly removes dirt, rust, oxidation, and other stains from your fiberglass boat, which then enables waxes to bond to the surface successfully.
What I liked the most about the Collinite Fiberglass Boat Cleaner is that it perfectly cleans and restores your fiberglass boat’s original color with no heavy scrubbing or buffing.
This lessens the chances of leaving scratches on your fiberglass boat’s delicate gelcoat.
It also augments the effectiveness of protective waxes applied to your boat’s fiberglass hull. This allows it to last longer, decreasing the times when you must clean and wax your boat.
The Collinite Fiberglass Boat Cleaner will restore your boat’s fiberglass to its former glory and help you prepare it for waxing, ensuring you that it stays that way.
6. Better Boat Instant Hull Cleaner for Fiberglass and Painted Boats
The Instant Hull Cleaner by Better Boat is a fiberglass cleaner that cleans your boat’s fiberglass hull and helps it keep its sparkling clean appearance.
Better Boat’s Instant Hull Cleaner effectively and effortlessly cleans your boat’s fiberglass of unattractive stains and rust, restoring it to the way it was before.
What I like about Better Boat’s Instant Hull is that it only takes one application to remove the stain, even the tough ones, on your boat’s fiberglass hull.
I also like how safe it is to use not only on fiberglass but also on gelcoats, aluminum hulls, and even painted surfaces. This makes it versatile and a great value for money. Plus, you don’t have to worry about it damaging other types of surfaces on your boat.
This coupled with its quick-acting time, makes the Better Boat Instant Hull Cleaner one of the best fiberglass cleaners available on the market.
7. Star Brite Instant Hull Cleaner
As its name suggests, the Star Brite Instant Hull Cleaner is designed to work instantly to remove dirt and stains from your boat’s fiberglass hull.
The Star Brite Instant Hull Cleaner is a cleaner that is great for removing things like yellowing, waterline stains, and grime.
Being able to remove these unsightly stains can greatly enhance your boat’s appearance. Although effective at removing such unsightly stains, the Star Brite Instant Hull Cleaner is perfectly safe for use on fiberglass and even on other surfaces like painted ones and metal. This is because it’s formulated without the use of acids that can be harmful to such surfaces.
What I like the most about the Star Brite Instant Hull Cleaner is its ease of use; you just need to wipe it on and rinse after a few minutes. I also liked that its easy-to-use nature means no scrubbing is required for it to remove those unsightly stains.
8. TotalBoat White Knight Fiberglass Stain Remover
The TotalBoat White Knight Fiberglass Stain Remover is a fiberglass cleaner that prides itself on being able to remove dirt, scum, rust, and waterline stains from your boat’s fiberglass and gelcoat.
What I liked about the TotalBoat White Knight Fiberglass Stain Remover is that its gel formula has a non-abrasive nature, which makes it safe for use on your boat’s gelcoat. You no longer have to worry about potential damage to it.
Another thing I liked about it is that it can be used on multiple surfaces, not just fiberglass, such as painted surfaces, stainless steel, and gelcoats. Moreover, it’s not only for marine use so you can use it even at home.
Although not as quick-acting as others, the TotalBoat White Knight Fiberglass Stain Remover still has a fairly fast-acting time, needing only 10-15 minutes for it to work.
Furthermore, the TotalBoat White Knight Fiberglass Stain Remover doesn’t require any scrubbing, so you can sit back and relax while waiting for it to remove the stains from your boat’s fiberglass.
9. MEGUIAR’S M6732 Marine/RV One-Step Compound
Earlier, I reviewed a three-step cleaning system by MEGUIAR, but if three steps are too many for you, then maybe the MEGUIAR M6732 Marine/RV One-Step Compound is the cleaner for you.
Like the MEGUIAR’S M4965 Marine/RV Fiberglass Restoration System’s three-step system, the MEGUIAR M6732 Marine/RV One-Step Compound is designed to clean your boat’s fiberglass and gelcoat thoroughly without harming it.
However, unlike the former, the MEGUIAR M6732 Marine/RV One-Step Compound does so with only one step, making it easier to use and more convenient for those who want to spend less time cleaning their boat.
What I loved about the MEGUIAR M6732 Marine/RV One-Step Compound is that it removed heavy oxidation stains, water spots, and scratches from my boat’s fiberglass and gelcoat while leaving behind a nice glossy finish.
Moreover, I loved how it restored my boat’s vibrant color, leaving it shiny and like a brand new boat in just one step.
Despite using an aggressive compound to remove those unsightly oxidation stains and scratches, the MEGUIAR M6732 Marine/RV One-Step Compound is still safe for use on fiberglass and other surfaces.
10. Biokleen BIO-KLEEN M0065 Fiberglass Cleaner
Looking for a fiberglass cleaner that is both effective at removing tough stains and environment-friendly can be tough.
However, Biokleen’s BIO-KLEEN M0065 Fiberglass Cleaner has made it possible to remain environment-friendly while still keeping your boat free of stains.
What I loved the most about the Biokleen BIO-KLEEN M0065 Fiberglass Cleaner is that not only does it produce amazing cleaning results, but it also enables me to remain environment-friendly.
It enables users to be more friendly to the environment through its special formula that’s free from chemicals like aerosol and other toxic ingredients that can pollute the water when exposed to it.
I also loved how versatile this cleaner is, for I can use it to clean just about any surface, not just my boat’s fiberglass hull. Furthermore, its non-abrasive yet highly clinging gel ensures that my boat’s gelcoat isn’t damaged.
It’s effective at cleaning and removing waterline stains and rust from my boat, leaving behind a sparkling clean hull, which enhances my boat’s overall appearance.
What to Look for When Buying a Cleaner for Fiberglass Boat
As with any purchase you make, you don’t buy the first fiberglass cleaner you find; you have to consider several factors before making your decision. After all, you’ll want a cleaner that’s effective at cleaning, not at damaging your boat’s exterior.
Selecting the right cleaner for your boat’s fiberglass hull can be a daunting task, but to make your life easier, I have created a list of factors, which you need to take into account before you buy one.
They are as follows:
Looking at what your cleaner of choice is made of is a good idea because you would want a cleaner that will remove all those pesky and unsightly stains and dirt without harming your boat’s fiberglass surface.
What’s ideal is a cleaner that is strong enough to remove the stains left behind on your boat’s fiberglass hull while still gentle enough not to damage your fiberglass and the gelcoat. A cleaner with a non-abrasive formula is best for this.
A fiberglass cleaner that can also be used on other surfaces like painted ones and metal is also worth considering as this increases its versatility.
Additionally, choosing a biodegradable, environment-friendly fiberglass cleaner would also be ideal for your boat’s hull since it’s the one that is in constant contact with the water, and a biodegradable cleaner would prevent polluting it.
- Response Time
A boat’s hull is a large surface, so of course, it would take time to clean all of it, especially when done by hand.
This is why it would be best to choose a fiberglass cleaner that acts quickly to allow you to spend less time cleaning and more time actually enjoying your boat.
However, ensure that when you choose a quick-acting fiberglass cleaner, it only removes the stain and not your boat’s paint and gelcoat.
- Ease of Application
Again, the hull is a large surface so cleaning it takes a lot of time. In addition to the response time, you should choose a fiberglass cleaner that is easy to apply and use so as to not use more time on application and cleaning.
Gel-type cleaners seem the easiest to use on large surfaces like your boat’s fiberglass hull as they are more solid and less messy than liquid-type fiberglass cleaners.
Their clingy nature also enables you to spread them more evenly and cleanly compared to liquid-type cleaners.
- Cleaning Power
This is one of the most vital factors you need to take into account, especially if you want to remove particularly stubborn stains from your boat’s exterior.
You would want to choose a fiberglass boat cleaner that is effective at thoroughly cleaning your boat’s fiberglass hull without stripping the paint or the delicate gelcoat.
However, you don’t always need strong formulas to remove tougher stains. Sometimes, all you need is another application. Moreover, knowing what type of cleaning you wish to do will help you decide what cleaner to get.
Everyone wants to ensure they get their money’s worth, so choosing a cleaner that’s versatile and can be used not only to clean your boat’s fiberglass hull but also on other surfaces, which is a good idea.
A fiberglass cleaner that can be used both for your boat and at home is a good cleaner that will give you great value for your money.
- Added Protection
Cleaning your boat’s fiberglass hull should not be the only thing your cleaner could do. It should also be able to give your boat that added protection to make your boat’s newly enhanced appearance last.
Waxes are especially good for additional protection to your boat’s fiberglass hull and gelcoat.
Some fiberglass boat cleaners are designed to include wax or polish in its formulation, so it might be worth checking out those type of cleaners.
Knowing what factors should be considered when picking a fiberglass boat cleaner will help you choose the one that best suits you and your boat’s needs. The right fiberglass boat cleaner will help preserve your boat’s aesthetic, leaving it looking fresh and like brand new.
Other Important Factors to Consider
While the aforementioned factors are important, there are other things you need to consider when choosing the right fiberglass cleaner for your boat.
With this part, I will list down other factors you need to know so that you can choose the best cleaner for you and your fiberglass boat.
Moreover, in this section, you will learn more about fiberglass boat cleaners and their importance.
What is a fiberglass boat cleaner?
A fiberglass boat cleaner is a cleaning solution that is specifically formulated to clean fiberglass surfaces such as your boat’s hull without damaging it and its gelcoat.
This type of cleaner enables you to not only remove stains and scratches from your boat’s fiberglass surface, but it also enables you to restore its overall appearance without overhauling it.
The reason for a specially formulated type of cleaner for fiberglass boats is because fiberglass is a delicate surface that can easily be damaged when the wrong type of cleaners such as ones with abrasive formulas are used on it.
How does it work?
Fiberglass boat cleaners work by penetrating deep into the stains and dirt, cleaning them thoroughly, leaving your boat looking sparkling clean and brand new.
Since fiberglass is a delicate surface and can easily be damaged, fiberglass boat cleaners use non-abrasive formulas that are tough on stains but easy on your boat’s surface.
What are the different types of cleaner for fiberglass boat?
The most common types of cleaner for fiberglass boats are the gel-type and liquid-type of cleaners.
Gel-types are the most commonly used type of cleaner for fiberglass boats as it clings more to your boat’s fiberglass surface and is easier to apply and use compared to liquid cleaners due to its less messy nature.
Liquid-type cleaners, on the other hand, can cover much more ground but can be difficult to control and messy compared to gel cleaners.
Why do you need a fiberglass boat cleaner?
As I mentioned before, your boat’s fiberglass hull is the most exposed part of your boat and is the one that takes the brunt of the damage caused by being constantly exposed to the water and, sometimes, harsh weather.
Your boat’s fiberglass hull, therefore, tends to succumb to wear and tear much faster compared to the other parts of your boat. This can leave your boat looking more worn out than it actually is.
Fiberglass boat cleaners help you restore your boat to its former glory by cleaning and removing the dirt and stains found on your boat’s exterior.
Furthermore, it does so without compromising the integrity of your fiberglass and its gelcoat.
There are many benefits to using a fiberglass boat cleaner such as:
- Restoring your boat’s shiny and vibrant exterior – Using a fiberglass boat cleaner will help you remove those pesky stains and dirt and enable you to restore your boat’s exterior, leaving it looking fresher and more vibrant.
With a fiberglass boat cleaner, people will think that your boat is once again brand new.
- Protecting your boat from further damage – A fiberglass boat cleaner will not only remove those unsightly stains and dirt from your boat’s exterior, but it will also give your boat’s fiberglass and its gelcoat that much-needed protection. This will help it keep its newly restored and clean aesthetic too.
- Increasing your boat’s value – Since fiberglass boat cleaners will help restore your boat’s exterior and make it more visually pleasing, the result would be an increase in your boat’s value. Having a boat with an aesthetically pleasing exterior would greatly increase your chance of attracting buyers if you ever decide to sell your boat.
- Increase your boat’s lifespan – Fiberglass boat cleaners do not only remove unsightly stains and keep your boat visually pleasing, but they also help keep your boat in top shape by cleaning and removing things like rust and residues that can weaken your boat hull’s integrity. Regularly cleaning your boat with a fiberglass boat cleaner will greatly increase your boat’s lifespan, allowing you to enjoy sailing for a long time.
Being able to clean and restore the fiberglass hull of one’s boat is something that all boat owners should know-how and be able to do. This will help them keep their boats in top shape and allow them to enjoy it much more.
Knowing the benefits of using a fiberglass boat cleaner and understanding what they are will help you decide not only what product to choose but also how important they are in prolonging your boat’s lifespan and preserving its visually pleasing exterior.
Frequently Asked Questions
Q: What are the most trusted fiberglass boat cleaner brands?
A: Some of the most trusted fiberglass boat cleaner brands have been mentioned in the product review section of my article. Star Brite, 3M, and Meguiar products are some of the most trusted fiberglass boat cleaner brands on the market.
These brands have been tried and tested. They have also been found to be effective at removing dirt and stains from fiberglass boats. Because of this, they are widely popular with their customers.
Q: Where to buy one?
A: Like most cleaners, you can buy fiberglass boat cleaners from hardware stores or boating supply stores if you’re looking for marine use-specific cleaners.
However, if you want a more convenient option, there are always online sites like Amazon where you can order your preferred cleaner and have it shipped directly to your home.
Q: How to clean fiberglass boat?
A: Using a fiberglass boat cleaner is the best way to clean fiberglass boat, but the steps on how to clean a fiberglass boat differ with each cleaner.
However, one of the most important things you need to do before applying your chosen fiberglass boat cleaner is to rinse the hull first with fresh and clean water.
Doing so will remove the initial layer of dirt, making the whole cleaning process easier for you.
You should also read the instructions of your cleaner carefully so as to avoid accidentally damaging the delicate gelcoat of your boat.
Q: How often should I clean my fiberglass boat?
A: There’s no fixed frequency on how often you should clean your boat’s fiberglass. However, you’re recommended to wash it as often as you possibly can, especially if you take it out on the water frequently.
Doing so helps prolong the lifespan of your fiberglass boat, which enables you to not only enjoy it for a long time but also help you save money on repairs.
Q: Can you use fiberglass cleaners whose ingredients include bleach?
A: You can, but using cleaners whose ingredients include bleach might end up damaging your boat’s fiberglass rather than restore it.
Bleach is a very harsh chemical and can be too abrasive especially for your boat’s delicate fiberglass and gelcoat.
While it’s possible to use bleach, I don’t recommend doing so if your aim is to prolong your boat’s exterior or restore it. It’s better to use fiberglass cleaners that don’t include bleach in their list of ingredients.
Q: Is it necessary to apply wax or polish after using fiberglass boat cleaners?
A: Although it’s not an absolute must, applying wax or polish on your boat’s fiberglass hull has many benefits.
Such benefits include added protection on your boat’s exterior, a shinier and more vibrant exterior, and increased durability.
However, it’s worth noting that if you decide to use wax after cleaning your boat, it’s not necessary to always to do so. Applying wax or polish at least twice every season is ideal.
Q: Is it possible to use fiberglass boat cleaners on other types of surfaces?
A: The answer to this really depends on your fiberglass cleaner.
Some are versatile and safe to use on other surfaces like painted surfaces, metal, and vinyl while others are meant only to work on fiberglass.
Q: Why is it important to use fiberglass boat cleaners?
A: Fiberglass cleaners are specially formulated for safe use on fiberglass, which is easily scratched and damaged by more abrasive cleaners.
Fiberglass boat hulls have also the additional concern of being in contact with water so most fiberglass boat cleaners are made with environment-friendly ingredients so as not to pollute the water when you take your boat out for sailing.
The special formulation of fiberglass boat cleaners ensures that you can clean your boat’s delicate fiberglass hull without worrying that the cleaner is too harsh for it or that it might damage it.
Q: Why do you need to clean your boat’s fiberglass hull?
A: As mentioned before, your boat’s fiberglass hull is the most exposed to the elements part of your boat, so it suffers from wear and tears much faster than the rest of your boat.
Regularly cleaning it from dirt, grime, rust, and stains helps prolong its lifespan, saving you from the potential costs of having it repaired or replaced earlier than expected. It also has the added bonus of enhancing your boat’s appearance.
Q: Which is better, gel cleaners or liquid cleaners?
A: The answer to this question boils down to personal preference.
Gel type cleaners are the more popular choice and are more commonly used due to their easy application and usage.
Moreover, gel cleaners are also much easier to spread evenly on your fiberglass surface compared to liquids.
Liquid type cleaners, on the other hand, can cover more of your fiberglass quicker. The only downside is that it can be messy and harder to control, especially the amount of product you use.
Q: What is a gelcoat?
A: Your fiberglass boat is covered in a special resin called a gelcoat, which is the one responsible for your boat’s fiberglass having that shiny and glossy appearance despite not adding much value to your boat’s structure.
The gelcoat is also the one that protects your boat’s fiberglass hull. Using cleaners that do not harm your fiberglass boat’s gelcoat is important because it helps protect and prolong the integrity of your fiberglass hull.
Cleaning your fiberglass boat is an important step in maintaining your boat and ensuring that it is in tip-top shape. Selecting the best cleaner for fiberglass boat is vital to do this.
Moreover, there are many benefits to having a constantly clean and polished fiberglass boat like having a boat exterior that looks shiny and new.
Additionally, it is not only visually pleasing, but having a sparkling clean fiberglass boat hull will also guarantee that you enjoy your precious boat for many years to come.
This is because regularly cleaning your boat’s fiberglass hull can increase its durability, making it last longer.
However, choosing the best cleaner for your boat’s fiberglass is no easy task, especially with the abundance of options available.
Hopefully, with my comprehensive product review and buyer’s guide, you will be able to determine what cleaner is best suited for your boat’s needs.
I am Dave, Marine Talk’s content creator. Boating experiences matter when planning a boat trip for your family or going by yourself. Therefore, I am here to tackle all things relevant to boating so even the inexperienced ones can start their boating safely.