The Best Sealers for Aluminum Boats for 2021

Nicholas Swartz
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Do your aluminum boat hulls have holes, fractures, deterioration, or are they just plain looking tired?

If so, you might be looking for a boat sealer. Here’s the deal:

If you’ve been boating for a long time, then you probably know about many of the many benefits of using a boat sealer.

For example, sealing your aluminum boats reduces the noise of the water against your aluminum hulls (especially if you start off with a new boat). And, they make your boats more attractive.

Now, let’s get down to business and discuss some of the different boat sealers for this application. Keep reading to learn more about what to look for and some of the best sealers for aluminum boats.

NameCategoryProduct
TotalBoat Aluminum Boat Leak SealerBest OverallTotalBoat Aluminum Boat Leak Sealer
Ruscoe Self Leveling Permanent SealerBudget PickRuscoe Self Leveling Permanent Sealer
Marine-Tex RM330K Gluvit Waterproof Epoxy SealerUpgrade PickMarine-Tex RM330K Gluvit Waterproof Epoxy Sealer

1. TotalBoat Aluminum Boat Leak Sealer

Our rating: 9 / 10

TotalBoat Aluminum Boat Leak Sealer

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Pros:

  • Easily applicable with a brush or spreader
  • Leaves a thin, clear, tough coating on the surface
  • Helpful to any aluminum boat owner
  • Leaves an anti-corrosive hydrophobic coating on surfaces
  • Can be applied over any paint job

This is a high-quality sealer that you can easily apply to virtually any surface.

It’s perfect for protecting aluminum surfaces. You will need to apply it over relatively clean surfaces. However, because it seals galvanic corrosion, it’s very easy to apply over existing paint jobs.

Your boat will be protected from the elements and contaminants for a long time to come.

2. 3M Marine Adhesive Sealant 5200

Our rating: 8 / 10

3M Marine Adhesive Sealant 5200

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If you’re looking to make sure your boat stays leak-free for years to come, then you need something that is going to do the job right the first time. We’ve gone through the top-rated sealants and found one that we believe will do just that …

The 3M Marine Adhesive Sealant 5200 is a one-part, fast-curing adhesive sealant that features an excellent bonding strength on a wide range of metals – including aluminum.

This sealant is recommended for use on boats, aluminum railings, marine fittings, etc. It is low odor and nonflammable and CCA- and UV-resistant. Once this sealant has dried, it can be painted over with a variety of coatings.

3. Hy-Poxy H-450 Alumbond 6.5 oz Aluminum Putty Repair Kit

Our rating: 8 / 10

Hy-Poxy H-450 Alumbond 6.5 oz Aluminum Putty Repair Kit

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This glass-fiber reinforced putty from Hy-Poxy offers solutions for all types of small holes in aluminum boats.

From rusted or corroded holes to holes caused by UV or gelcoat, the H-450 one-part silicone compound will fill in holes and protect against further deterioration.

Thanks to its glass fiber content, this aluminum repair compound will withstand vibration and common stresses encountered during normal use.

4. Woody Wax Metal Sealer

Our rating: 8 / 10

Woody Wax Metal Sealer

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Pros:

  • Affordable and comes in a 16-ounce size
  • Nice for touch-ups
  • Can be used on metal, plastic, and wood
  • Can be applied to interior and exterior surfaces

Cons:

  • Not for large areas
  • Can take about four or more hours to completely cure

16 oz.

Products like this Woodsy Wax Metal Sealer are awesome for touch-up purposes. It’s a very affordable sealer and seems to serve a variety of uses.

It comes out of the can in a viscous, elastic form. The consistency is somewhat like that of hair gel or hair dye. It has a similar consistency to the Liquid Wrench liquid thread locker, but infinitely thicker.

5. Amazing GOOP 5400040 Coat-It Waterproof Epoxy Sealer & Protector

Our rating: 8 / 10

Amazing GOOP 5400040 Coat-It Waterproof Epoxy Sealer & Protector

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Pros:

  • Easy to use
  • Does not leave a sticky residue
  • Waterproofs and protects against cracking
  • Suitable for a variety of outdoor surfaces like wood, metal, concrete, and vinyl
  • Lasts for several years
  • Easy to clean off with soap and water
  • Reasonably priced
  • If necessary, you can stir it with a plastic non-metal brush

The amazing GEOP 5400040 Coat-It Waterproof Epoxy Sealer and Protector is a great product that makes your wood surfaces water-resistant against cracking. The best thing about it is that it does not leave a sticky residue. It is also made in the good old USA!

Let’s take a look at the pros and cons of this sealer. The amazing GEOP 5400040 Coat-It Waterproof Epoxy Sealer and Protector is available only for shipping to the following states: New Hampshire, Vermont, New York, Massachusetts, Rhode Island, Connecticut, Maine, and New Jersey. Before you buy this product, make sure to check if you are buying it from a seller that ships to your state.

6. Ruscoe Self Leveling Permanent Sealer

Our rating: 7 / 10

Ruscoe Self Leveling Permanent Sealer

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Pros:

  • Easy to use
  • Performs well on all styles and conditions of aluminum

Cons:

  • Does not seem to have a shelf life
  • Provides a light shine to aluminum

Ruscoe Self Leveling Permanent Sealer is used to create a lasting protective layer that resists dirt, corrosion, and rust on any type of aluminum alloy. This sealant is a one-step application and is easy to use. The sealer is self-leveling and requires no rubbing to create a smooth finish.

This sealant can be used on the interior and exterior of your motor vehicle, boat, trailer, R.V., sun room, storage shed, or any equipment, etc. that requires a durable, easy to clean, self-leveling finish. Ruscoe Self Leveling Permanent Sealer is easy to apply and the application process is quick drying.

This sealant is able to be applied in 35 to 50 minute drying times. It is recommended that you apply a second coat after the sealant has cured for 120 hours. The sealant can be applied over sanded or faded surfaces, epoxy coatings, and over all previously applied sealers, paints, and coatings with no detrimental effects.

7. Marine-Tex RM330K Gluvit Waterproof Epoxy Sealer

Our rating: 7 / 10

Marine-Tex RM330K Gluvit Waterproof Epoxy Sealer

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Pros:

  • Heavy-duty all-in-one system
  • Base coat, color coat, and hardener included
  • Sticks and adheres extremely well
  • Dries to a rock hard, water tight finish
  • Very easy to work with; can be poured, brushed, or sprayed
  • Has an indefinite shelf life

If you're looking for the best aluminum boat sealer, then the MarineTex RM330K Gluvit Waterproof Epoxy Sealer is for you. It can be used to seal just about anything: marine and automotive; interior and exterior; below and above waterline.

This epoxy is self-leveling, and it's been formulated to prevent and stop corrosion, so you'll never have to worry about it washing off. Plus, it can be applied to virtually any surface including fiberglass, copper, brass, aluminum, wood, and many more.

It's very thick, so it won't run and drip, which will make it easier for you to get a smooth coat.

Frequently Asked Questions (FAQ)

How do you stop an aluminum boat from leaking?

As was mentioned previously, aluminum is a great material for boats and it certainly makes for some great boats. However, aluminum is by no means perfect. One issue that comes up quite a bit with aluminum boats is leaking. The same issues that cause general water entry can also cause you to lose circulation. Here’s how to seal up your hull if it is leaking.

How do you seal a riveted aluminum boat?

A lot of people want to know how to get their aluminum boat to last longer and keep looking good.

I’ve used Sikaflex 290 extensively in this regard and have been pleased with the results. The key is to follow the instructions to the T. For the first two years you should pull the boat out of the water and put a coat of sealant on it every year. If you use Sikaflex 290 like I do, give it a good day or two to cure. The Sikaflex website explains this in more detail but the big thing to remember is that you don’t want to be using a boat “water ready” for at least a week.

Can You Use Flex Seal on aluminum boat?

Yes, you can use Flex Seal on your boat but there are a few factors to consider before you start.

First, paint is a much better and permanent solution. You shouldn't use Flex Seal on a boat that already has paint or you could remove it. Flex Seal can't be applied over a painted surface.

You also have fewer options with painting your boat than sealing it with Flex Seal. It is more expensive to use acrylic paint on aluminum than it is to seal your boat with Flex Seal.

Finally, painting your boat will last much longer than sealing it with Flex Seal. You will have to reapply Flex Seal every year or two while paint will last at least 4-5 years and often longer than seven. After that, you can repaint your boat with new paint, but it will cost at least several hundred dollars to do so.

Is there a sealant that can be applied underwater?

Yes. Most reputable manufacturers should be able to provide you with a product that can be applied underwater. A lot of people seal their boats using underwater epoxy kits even when they apply it on dry land because it is so much easier. Once you have it underwater, you have to bear in mind that most coatings won’t stick to the surface below them. So, if you want to reapply later, you will need to roughen the fiberglass and apply a new coating.

Because of this, some tend to opt for a UV light-cured coating. UV light is much more forgiving in terms of application. You can even get one of those UV flashlights for when you want to check for cracks at night.

Conclusion

When you are trying to figure out which boat covers to buy, you want to make sure that you are only buying top quality covers to protect your boat from the sun, the rain, and make it easy for rainy days to transport.

However, some boat covers don’t provide the protection that you need. Sometimes it’s the protectors that are too flimsy, and other times, the zippers are too fragile … things that cause leaks and let the water in!

Our Recommendation

NameCategoryProduct
TotalBoat Aluminum Boat Leak SealerBest OverallTotalBoat Aluminum Boat Leak Sealer
Ruscoe Self Leveling Permanent SealerBudget PickRuscoe Self Leveling Permanent Sealer
Marine-Tex RM330K Gluvit Waterproof Epoxy SealerUpgrade PickMarine-Tex RM330K Gluvit Waterproof Epoxy Sealer