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Proven Ways to Remove Mildew From A Boat: Expert Tips and Tricks

Proven Ways to Remove Mildew From A Boat: Expert Tips and Tricks

Mildew is a common problem for boat owners, especially during humid weather conditions. It can cause unsightly stains, bad odors, and even damage to the boat’s canvas and upholstery. Removing mildew from a boat can be a daunting task, but with the right tips and tricks, it can be done effectively.

Identifying Mildew on Your Boat

Mildew is a type of fungus that thrives in warm, humid, and damp environments. It can grow on almost any surface, including boat cushions, carpets, sails, and canvas covers. Mildew is often mistaken for dirt or dust, but it can cause serious damage to your boat if left untreated. Here are some signs to look out for to identify mildew on your boat:


One of the most common signs of mildew is a musty odor. If you detect a damp, earthy smell on your boat, it is likely that mildew is present. This smell can be particularly strong in confined spaces, such as cabins or storage areas.


Mildew stains are another indication of mildew growth on your boat. These stains are usually black, brown, or green in color and can be found on cushions, carpets, and other surfaces. If you notice any discoloration on your boat’s surfaces, it is important to inspect them closely for mildew.


Mildew can also change the texture of surfaces it grows on. For example, boat cushions may become stiff or crusty, and canvas covers may feel rough or gritty. If you notice any changes in the texture of your boat’s surfaces, it is important to investigate further to determine if mildew is the cause.

By being vigilant and identifying mildew early on, you can take steps to remove it before it causes serious damage to your boat.

Importance of Removing Mildew

Mildew is a common problem that boat owners face, and it can be a serious one if left untreated. Mildew is a fungus that thrives in damp and humid conditions, and it can quickly spread throughout a boat if not dealt with promptly. It not only looks unsightly but can also cause damage to the boat’s surfaces, including canvas, vinyl, and cushions.

One of the main reasons why it’s important to remove mildew from a boat is that it can cause health problems. Mildew can produce allergens that can cause respiratory problems, especially for those who suffer from allergies or asthma. The spores can also cause skin irritation and other health issues, making it important to tackle the problem as soon as possible.

Another reason why it’s important to remove mildew is that it can weaken the boat’s surfaces. Mildew can eat away at the stitching on seats and cushions, causing them to become weak and brittle over time. This can lead to costly repairs or replacements.

Furthermore, mildew can also cause a foul odor that can be difficult to get rid of. This can make it unpleasant to spend time on the boat, and it can also make it difficult to sell the boat if the owner decides to do so.

Proper Boat Maintenance: Prevention Over Cure

When it comes to mildew, prevention is always better than cure. Proper boat maintenance is key to preventing mildew growth. Here are some expert tips and tricks to keep your boat clean and mildew-free.

Regular Cleaning

Regular cleaning is essential to prevent mildew growth. Make sure to clean your boat thoroughly after every use. Use a mild soap and warm water to clean all surfaces, including the canvas, vinyl seats, and carpets. Rinse everything thoroughly with clean water and let it dry completely.

Ventilation and Moisture Control

Moisture is the main culprit behind mildew growth. Proper ventilation and moisture control are crucial to prevent mildew. Make sure to keep your boat dry and well-ventilated at all times. Open hatches and windows to allow fresh air to circulate. Use a dehumidifier or moisture absorber to keep the air dry.

Use of Mildew Resistant Materials

Using mildew resistant materials is another effective way to prevent mildew growth. Choose fabrics and materials that are specifically designed to resist mildew. Sunbrella and other marine-grade fabrics are excellent choices for boat covers, cushions, and upholstery. Use mildew-resistant paint and coatings for wood and metal surfaces.

Expert Tips for Mildew Removal

Mildew can be a pesky problem for boat owners. However, with the right tools and techniques, it can be easily removed. Here are some expert tips for mildew removal:

Choosing the Right Cleaning Products

When it comes to choosing the right cleaning products for mildew removal, it’s important to consider the type of material that needs to be cleaned. For vinyl boat seats, a soft bristle brush or magic eraser sponge can be used to remove loose dirt and debris. For canvas, a mixture of borax and warm water can be used to loosen up the mildew.

Bleach-based cleaners are also effective at killing mold and mildew. However, it’s important to take the proper safety precautions when using bleach. Always wear gloves and eye protection, and make sure to properly ventilate the area.

Effective Cleaning Techniques

Once the right cleaning products have been chosen, it’s important to use effective cleaning techniques to remove the mildew. For canvas, gently scrub the borax mixture into the material and allow it to soak into the fibers. For vinyl boat seats, use a gentle scrubbing motion with the soft bristle brush or magic eraser sponge.

For severe mildew stains, a solution of bleach, water, TSP, and powdered laundry detergent can be used to effectively remove the mildew. Mix four quarts of freshwater, one quart of bleach, 2/3 cup TSP, and 1/3 cup of laundry detergent in a bucket. Apply the solution to the affected area and allow it to sit for 10-15 minutes before scrubbing with a brush.

Safety Measures During Cleaning

When cleaning mildew, it’s important to take safety measures to protect yourself and others. Always wear gloves and eye protection, and make sure to properly ventilate the area. If using bleach-based cleaners, avoid mixing bleach with other cleaning products as it can create toxic fumes.

It’s also important to follow the instructions on the cleaning products carefully to avoid damaging the material being cleaned. Test a small, inconspicuous area first before applying the cleaner to the entire surface.

Professional Mildew Removal Services

For boat owners who are not comfortable with removing mildew on their own, there are professional mildew removal services available. These services can be a great option for those who want to ensure that the job is done properly and thoroughly.

Professional mildew removal services typically use specialized equipment and cleaning solutions to remove mildew from boats. They have the experience and expertise to identify the source of the mildew and take the necessary steps to prevent it from returning.

One benefit of hiring a professional service is that they can often provide a guarantee for their work. This can give boat owners peace of mind knowing that if the mildew returns, the service will come back to fix the issue.

However, it’s important to note that professional mildew removal services can be expensive. The cost will depend on the severity of the mildew and the size of the boat. It’s recommended to get multiple quotes from different services to ensure that you’re getting a fair price.

Long-Term Mildew Management Strategies

Regular Inspections

One of the best ways to prevent mildew growth on a boat is to conduct regular inspections. Inspect all areas of the boat, including the hull, deck, and interior, for signs of moisture and mildew growth. Pay close attention to areas that are prone to moisture, such as the bilge, the head, and the galley.

If you find any signs of mildew growth, it’s important to address the problem immediately. Use a mildew remover or a solution of bleach and water to clean the affected area. Be sure to wear protective gloves and a mask to avoid inhaling any fumes.

Seasonal Boat Care

In addition to regular inspections, it’s important to take care of your boat on a seasonal basis. Before storing your boat for the winter, take the following steps to prevent mildew growth:

  • Clean the boat thoroughly, removing any dirt, debris, and mildew.
  • Dry the boat completely, using a fan or a dehumidifier if necessary.
  • Apply a mildew inhibitor to all surfaces, including the hull, deck, and interior.
  • Cover the boat with a breathable cover to prevent moisture buildup.

When you’re ready to use your boat again in the spring, be sure to inspect it thoroughly for any signs of mildew growth. If you find any, address the problem immediately to prevent it from spreading.


Mildew is a common problem that boat owners face, but it can be easily managed by following a few simple tips. The first step is to keep the boat clean and dry, as moisture is the main cause of mildew growth. Regular cleaning and airing out of the boat can go a long way in preventing mildew from forming.