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How to Remove Mildew From Boat Seats Once and for All

Fact checked by William Hart

how to remove mildew from boat seats

If you have been into boating for a while, you might realize how easily mildew and mold can develop on boat furniture. No matter how careful I am, the mildew keeps coming back again.

They look really unpleasant, especially on white chairs. I’ve tried almost everything: washing detergents, baking soda, all-purpose cleaners, and even dish soap. After many trials and errors, I finally came up with the best way to remove mildew from boat seats.

In short, you will need mold removers or white vinegar. Spray the product on the surfaces, let it sit, scrub off the greenish dots, and wipe the seats with a clean cloth. If there are still tough spots left, use magic eraser sponges. They are the ultimate weapons against mold. Finally, apply vinyl protectant to stop the mold from coming back.

For detailed information on how to remove mildew from boat seats, dive in!

Table of Contents

What You Will Need


With the right products, cleaning mildew off boat seats is relatively quick and easy. The whole process might take you under ten minutes. Here is what you will need.

1. A mold remover or white vinegar

The most popular boat seat upholstery is vinyl. The material is plastic or synthetic resin consisting of polyvinyl chloride or a type of polymer. It feels almost like plastic. If you’re working with vinyl boat seats, avoid bleach or any detergents that contain bleaching ingredients because bleach will dry out vinyl, leaving them vulnerable to weathering and easier to crack.

Instead, use a mold remover that doesn’t contain bleach. This remover comes with a foam sprayer that allows the application to be faster and easier, even on hard-to-reach areas.

Every boat owner knows mold and mildew are unavoidable. They appear on your swiveling chairs, boat carpet, and wooden deck. Hence, bleach-free remover will be a big help in maintaining the boat’s best conditions.

If you don’t want to buy mold removers, white vinegar can be an alternative. It doesn’t contain any bleach or harsh chemicals while having great cleaning power. Also, vinegar can kill most bacteria. Grab the vinegar bottle in your kitchen, it will be helpful.

2. Magic eraser sponges

To treat stubborn stains, you will need magic eraser sponges from Mr. Clean or Oh My Clean. This product will clear out the toughest dirty spots. Oftentimes, mildew leaves a greenish layer on the surface after cleaning no matter what removers you use. Magic erasers will remove mildew stains from vinyl boat seats.

3. A soft brush and cloth

Prepare a soft bristle brush for scrubbing. The brush should be small enough to reach the folds, gaps, and seams. Avoid hard bristle brushes as they can damage the fabric or even tear the chair upholstery apart, especially old and brittle ones.

After scrubbing, you need several pieces of cloth to wipe off the surface. Any cloth will work but for optimal cleaning, we recommend microfiber cloth. Microfiber is highly moisture-absorbing and doesn’t leave fabric shreds behind.

4. Vinyl protectant

Last but not least, once the cleaning procedure is done, you need a vinyl protectant to prevent mold and mildew from coming back. One of the best protectants is the 303 Marine UV Protectant Spray. The product has a matte finish and is non-toxic. You can use it on vinyl, plastic, fiberglass, rubber, and even leather. Besides keeping the mold away, it will block UV, slow down the aging process, and prevent cracks.

Steps to Clean Mildew From Boat Seats


Now that you have all the right products, follow these steps to clean mildew from boat seats. Remember to put on rubber gloves or other safety gear as needed to protect yourself from mold spores and acidity in vinegar. They can irritate sensitive skin.

1. Clean the surface

If you choose to use mold removers, proceed as below:

  • Start by spraying a decent amount of mold remover onto the seats. Don’t forget the folds and gaps; mold tends to stick to those areas.
  • Wait for at least five minutes. If the stains don’t seem to dissolve, let the remover sit a bit longer.
  • Gently scrub using a soft bristle brush. This shouldn’t take long as the removers already broke down the mildew layer.
  • Wipe the surface with a microfiber cloth using circular motions to clean all residues. You can follow the product instructions to get the best results.

White vinegar is an excellent replacement for mold removers. I figure removing mold from boat seats using white vinegar right after I spot it is extremely effective.

However, it is not a product specifically designed for cleaning; it won’t be able to remove mildew that has formed for a while. Follow these steps to remove mold on boat seats using white vinegar:

  • Make a mixture by adding one part of white vinegar to nine parts of water. Swirl well and pour the mixture into a spray bottle.
  • Spray the mixture evenly onto the moldy areas.
  • It might take longer for vinegar to dissolve mildew; you should wait at least ten minutes.
  • With a soft toothbrush, gently scrub the chair surface. Feel free to spray more vinegar as you go.
  • Wipe the mold off using a paper towel.
  • Dip a microfiber cloth into vinegar, then apply it until the surface is saturated and wait for around fifteen minutes. This will kill the mold from its root.
  • Finally, rinse off the chair with a damp cloth and let it dry.

2. Repeat if necessary

Heavy mildew buildup won’t come off the first time you clean, so repeat the procedure. Spray cleaner, let it settle, scrub, and wipe away the remains. For tougher and more stubborn stains, the above steps may not be enough though. If you’ve done the process three or four times and a patch of mildew won’t go away, it’s time to pull out the magic erasers.

3. Use magic erasers

Magic eraser sponges can save you a lot of time. They come with powerful cleaners inside. All you have to do is get them wet, squeeze out the excess, and start wiping. In addition, magic erasers are helpful in cleaning up messes on many surfaces like fiberglass or teak deck, window frames, rod storage, and livewell surfaces. Keep a pack on your boat to wipe off any coffee spills, fish blood, or wet dog prints the moment they appear.

You might need several sponges to remove all mildew and mold. Remember to take the process easy and be gentle with the seats. Clean seats that are damaged are not nicer. To take a shortcut, you can skip the first two steps and start with magic erasers. But most of the time, you don’t need such cleaning power for mold stains.

4. Apply vinyl protectant

Now, your seats look nice and clean. But they won’t stay that way for long if you don’t apply the vinyl protectant. Boat seats are exposed directly to all kinds of harshest weathering; they need extra attention. Plus, applying the protectant only takes a few minutes. Simply spray it on and wipe it dry with a clean cloth.

Additionally, here are a few tips to prevent mildew from coming back:

  • Wipe off the seats after use with paper towels. Though the chairs might not look wet, a day on water definitely leaves moisture on the surfaces. Mold and mildew develop from wetness and humidity. Once you dry the boat seats, they won’t stand a chance.
  • Keep an eye on your boat seats during winterization. Mold tends to form on things that are not in use. Clean it up immediately once you spot the greenish layer.
  • Purchase mold-resistant seats. These will save you from the hard work of scrubbing and wiping. However, after a long time in use, mildew might start to develop even on mold-resistant materials.
  • Most importantly, clean your deck, carpet, and chairs every two to three months to keep the boat in its top shape.


Removing mildew from boat seats shouldn’t take much time and effort once you have the right products and techniques. So, spend a little time cleaning them up. A boat is a huge investment and the more you care about it, the more you get when you sell or trade your vessel. Plus, no boat owners want the whole crew to stand during a boat trip because of moldy chairs.

Please feel free to save this article on how to remove mildew from boat seats to refer back to in the future. Don’t forget to use our tips to keep the mold away. Remember that prevention is better than cure. Before you leave, let us know your thoughts in the comment section. See you then!

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