How to Clean Boat Fenders and Bumpers (4 Simple Steps)

how to clean boat fenders

It doesn’t really matter how much time and effort you put into cleaning your boat if those fenders that hang off of its sides are stained, discolored, and covered in muck. But more than just the cosmetic issues they bring, dirty fenders and bumpers also pose a risk to your beloved boat.

Just like any other part of your watercraft, those fenders require unique care and maintenance that might not be too obvious at the get go. So if you were wondering how to clean boat fenders and bumpers, this guide should bring you up to speed.

How Do Boat Fenders Get Dirty?

What causes all those stains in the first place? It’s not like your fenders are immersed in water anyway. Well, even if they might not lick the surface of the waves, boat fenders can get dirty because they’re exposed to all of the same elements as the rest of your boat - and perhaps even more.

Splashing waves can get your fenders wet with water that you probably never get the time or the opportunity to wipe off. Humidity and UV radiation also play an obvious role in the discoloration and staining of your trusty fenders. And let’s not forget, those bumpers take the brunt of impact (no matter how minimal) when your boat gets a little too close to its neighbors, slip or dock.

So what kind of contamination can you expect? Well, yellow stains are particularly common, but mold and mildew are a pretty close second. Then of course there’s the expected accumulation of dirt especially along the areas where the fenders might have seams or creases.

What You’ll Need

To clean your boat fenders, you’re going to need the proper equipment and cleaning products. Because most boat fenders are made from a durable marine-grade vinyl, it’s imperative that you choose cleansers that are formulated specifically for use on vinyl. Anything else could potentially erode or damage the material and shorten the lifespan of your beloved bumpers.

Here’s what you’ll need:

Dish Soap

dish soap

Unbeknownst to most boat owners, dish soap plays a major role in boat maintenance. The stuff is mild enough to get rid of most stains but doesn’t contain harsh chemicals that could scuff up or damage surfaces.

We like using the Dawn Ultra Dishwashing Liquid Dish Soap.

Buckets and Clean Water

Just one bucket might be more than enough to get the job done. You might also want to consider using distilled water since it doesn’t contain any minerals that could exacerbate mineral stains and hard water spots.

Scrub Brush

scrub brush

Soft bristle brushes might do the job, but it probably won’t hurt too much to get something a little stiffer. If you end up buying a hard bristle brush, just try to dial down on the pressure to prevent excessive scuffing.

Try out the Scrub Brush from JIESHKE with an Easy Grip.

Magic Eraser

magic eraser

This one’s a bit of an optional cleaner that you can pull out in case you’re faced with stains and discoloration that’s too hard to get rid of with mild soap and brushing. Magic eraser works well on boat seats, and many other things too.

We always rely on the trusty Mr Clean Magic Eraser.

Pressure Washer

pressure washer

Again, this one’s optional. But if you don’t have the time or the energy to gently scrub at your fenders, then a pressure washer can help significantly reduce the amount of time and the effort you put into the process.

We recommend the Sun Joe Electric Pressure Washer with Hose Reel.

Mold and Mildew Remover

mold and mildew remover for your fenders

If mold and mildew stains cover the surface of your bumpers, then you might want to use a dedicated solution to get them out. Just make sure it’s safe for use on vinyl.

Check out the Star Brite Mildew Stain Remover.



To make sure your bumpers and fenders are protected from future stains and cosmetic issues, buy a bottle of protectant spray. This should help minimize the risk of all sorts of contamination and even extend the life of your fenders.

We like using the 303 Marine UV Protectant Spray.

How to Clean Boat Fenders

ways to clean boat fenders

Now that you’ve got all the essentials you need for the job, it’s time to start the cleaning process. Follow these steps for a thorough cleanse and get your bumpers looking brand new in no time:

1. Perform a Preliminary Clean

Mix together a fourth of a cup of dish soap and a gallon of distilled water in a bucket.

Take a rag and use it to wash off any accumulated dirt on your bumpers. The purpose of course is to get rid of any dirt and debris that you could easily wash off without the need for added force or pressure.

Rinse the soap off when you’re done.

2. Spray Mold and Mildew Remover

If you’re seeing mold and mildew stains, now would be the time to spray a generous amount of mold and mildew remover.

Leave the formulation on for 10 to 15 minutes to let it dissolve the stains and then scrub with your brush.

Rinse with clean water when you’re done.

3. Use Magic Eraser or a Pressure Washer for Tougher Stains

For those deep seated stains that just won’t come off, you can try Magic Eraser. Keep in mind that this stuff can be abrasive, so take it easy and dial down on the pressure.

Work in small circles and treat just the areas that need the extra hand.

Alternatively, you can use your pressure washer at a low setting to blast off remaining stains.

4. Dry Them Off and Apply Protectant Spray

Once the stains are all out, leave the bumpers in the sun to dry. Of course, you could also just use a clean microfiber towel and pat dry it yourself to speed up the process.

When it’s all dry, take your protectant spray and give your bumpers a well deserved spritz to cover all of its surfaces and prevent stains.

You can also wipe the spray around until it dries to make sure it’s covering the entire fender.

Do’s and Don’ts When Cleaning Boat Fenders

It’s only normal for a boat owner to explore their cleaning options especially when there’s a limited supply of cleaning products at home. But before you grab for those seemingly viable cleaning solutions, you might want to understand the do’s and don’ts of proper fender cleaning.

What To Do

  • Opt for cleaners you might have at home like dish soap, bleach and liquid detergent.
  • Always dilute your chosen cleaning product to prevent any potential damage on your fenders.
  • Dial down on the scrubbing pressure to get rid of accumulated filth without scuffing or scratching your fenders' surfaces.
  • Clean your fenders regularly to prevent stains and discoloration from becoming too tough to remove.

What NOT To Do

  • Never paint over your fenders to provide 'protection'. Paint can stain the sides of your boat if and when they bump against each other.
  • Avoid strong chemical solvents like alcohol and acetone.
  • Don't get your pressure washer to the highest setting when cleaning your bumpers.

Boat Fender Maintenance Tips

boat fender maintenance

Yes, you can clean your fenders and get them to look brand new. But that’s no reason to have to do the process every time. The best way to keep your fenders looking clean would be to perform the proper maintenance tactics. Here’s what you can do to prevent stains and keep your bumpers bright and clean:

Keep Them When Not in Use

This one’s pretty obvious. You’re only going to need your fenders when you expect to be in close contact with other boats or the dock, such as when you park in a slip. If you don’t think you’ll need them, dry them up and tuck them away into storage so they can be protected from the elements.

Use Fender Boards or Covers

Fender boards sit against your fenders and protect them from dirt and grime that might come off of other boats or the dock. Again, they might require their own maintenance. But since they’re made of wood, you can just as easily blast off any muck with a pressure washer.

You can also try fender covers, but then again, those need their own unique care and maintenance practices. But if you prefer laundering covers over scrubbing your fenders, then bumper covers might be worth a try.

Routine Cleaning

Well, this one’s pretty obvious. The best way to keep your fenders clean would be to subject them to routine cleaning. For most boat owners, cleaning bumpers and fenders along with other vinyl items around your boat (such as boat seats) proves to be most convenient since they could require all of the same cleaning materials.

This lets you pull out the same arsenal for the cleaning job so you can hit two birds with one stone.

Defending Your Fenders

Those fenders do quite a lot to keep your boat protected, so it’s only proper that you give them a little well-deserved TLC. Once those stains and blemishes start to show, pull out your cleaning kit and get to work.

Now that you know how to clean boat fenders and bumpers, you should be able to get the job done in no time. And don’t forget to add bumper cleaning to your routine maintenance checklist to keep your vessel in tip-top shape all year round.

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