8 Best Exterior Polyurethanes | Reviews + Buyer’s Guide

Apart from providing a smooth finish, exterior polyurethane ensures that any surface remains protected for a long time. As such, over the years, it has become an essential component of a DIYer’s repertoire. 

However, choosing a quality exterior polyurethane that provides a deep, rich shine and is resistant to UV rays is not that simple. With the availability of various options on the market, the entire selection process can get quite complicated and time-consuming. 

That’s why we have tried to make your job easier by handpicking the 8 best exterior paint options currently available on the market. Don’t worry; it was only after extensive research and testing that we provided detailed reviews for each of our recommendations.

So, without any further delay, let’s get started!     

Best Exterior Polyurethanes 

Here's the list of the 9 best exterior polyurethane options to help you achieve a smooth finish and long-lasting protection for your wooden surfaces.

1. Rust-Oleum 250041H - Best for UV Protection

Founded in 1921 in the US, Rust-Oleum is one of the leading manufacturers of innovative coatings that empower professionals and DIYers alike. Formulated to deliver resistance to UV rays, the 250041H Ultimate Spar Urethane does a magnificent job of protecting wooden surfaces from discoloration due to the sun’s rays. 

Firstly, this exterior polyurethane is produced using a water-based formula, which makes it easy for users to apply and clean up. For any exterior polyurethane, the odor is a major issue, but you would be glad to know that you will barely be able to smell any odor with this product.  

Once applied, it dries in just 30 minutes, which is an added advantage for professionals who need to paint many surfaces in a short time. What’s more, a quart of this solution can cover up to 87 square feet, which in our opinion, is pretty decent.

Furthermore, the formula is non-yellowing, which helps ensure that the wooden surfaces look great for a long time. Coupled with this is a crystal clear, gloss finish that takes the visual appearance of the surfaces to the next level by offering a clean and polished look.    

We were quite pleased with the results delivered by it. However, the manufacturer needs to pay attention to the packing material used for shipping. One of the cans was a bit dented when it came to us, which was a bit of a disappointment, given the brand’s popularity.  

2. Minwax - Best for Versatility

Next up, we have a highly effective product from the house of Minwax, a brand that is committed to helping consumers meet every wood finishing need. On that note, meet the 630500444 Helmsman Spar Urethane that delivers satisfying results on most projects.

We were thoroughly impressed with what this product had to offer. For starters, it contains UV blockers that help minimize the sun’s fading and reduces graying effects to a bare minimum. 

From outdoor furniture to kitchen countertops, you can use this polyurethane on a range of surfaces as per requirements. On top of that, it contains special oils that enable the finish to contract and expand with the wood as temperature and seasons change. This means you can trust the coating to stand the test of time with ease. 

We also loved that despite all the durability-enhancing additives, it maintains a crystal clear finish, making it a perfect choice for using over stains and light-colored wood. Finally, it is available on the market at a budget-friendly price, so you don’t have to pay for an arm and a leg for it.   

The only gripe we have against it is that it is a little too thin; it tends to soak into certain surfaces. As such, you would require more than one coat to achieve optimal results. Other than that, it works perfectly well and is worth the investment. 

3. Rust-Oleum 207008 - Best for Marine Use

As you already know, Rust-Oleum is one of the leading manufacturers of innovative coatings, so it made sense to add yet another quality unit from the brand to our list. The brand’s 207008 Marine Spar Varnish is made of flexible yet thick polyurethane formula, which withstands tough weather conditions and adds brilliant color.  

For us, the main highlight of this product is its spar varnish, which besides maintaining an exceptional shine, offers top-notch resistance to damaging elements like salt, UV rays, and mildew. Therefore, durability would be the last thing to worry about with this product. 

Thanks to the detailed instructions, you can easily apply and clean the coating in no time. Now, users owning boats will especially love this product, as it contains an antifouling formula that is specifically designed to prevent the buildup of marine growth on the boat’s base. 

Apart from boats, it can be applied on a variety of other surfaces including, decks, walkways, rails, bare metal, and a lot more. Beyond that, it features an affordable price tag, ensuring that it delivers exceptional value for money. 

Overall, it is one of the top-rated products out there.   

This product is an exceptional choice, considering its affordable pricing and durability. However, this might not be the right product for those looking for a thick layered varnish that wouldn’t darken or yellow the wooden surfaces. Also, it has a longer drying time, which again might not be to the liking of some users. 

4. Rust-Oleum 260165

Our next item is yet another Rust-Oleum polyurethane that works perfectly to offer top-quality finishes. Made using a water-based acrylic formula, the 260165 Ultimate Polyurethane from the brand delivers a protective matte finish that helps in reducing smudges and fingerprints. Let’s take a closer look at this product in the next few sections. 

In our opinion, the USP of this product is its versatility. This coating can be applied on a wide range of interior surfaces such as trims, doors, cabinets, and more. Being water-based, it allows an easy cleanup, which can be done using just water and soap. Sounds good? Well, there’s more. 

It has a drying time of 1 hour, which can actually be beneficial for DIYers and professionals working on projects that require small corrections. Plus, it offers a 150 square feet per quart coverage area, which we believe is ideal for nailing small projects. 

As far as durability is concerned, the coat delivers exceptional stain and scratch-resistant finishes on wooden surfaces that can last for years to come. All these features make this product an option you certainly wouldn’t want to miss out on. 

A handful of users have complained that this product is not meant to be applied on white-colored wood as there was noticeable amber discoloration of the surface. But other than that, the product seems to be very handy in protecting a range of wooden surfaces.

5. TotalBoat Gleam Marine Spar Varnish

We are halfway through this list, and now it’s time to talk about a highly sustainable and affordable product from TotalBoat. Available in satin and gloss, the Gleam Marine Spar Varnish from the brand promises to have something in store for those looking to preserve the beautiful finish on exterior surfaces.  

To begin with, this classic marine varnish features phenolic resins and premium tung oil that works to deliver a warm, beautiful, and transparent ambient finish on a variety of surfaces. Plus, it’s easy to apply; hence you get a durable and radiant finish without breaking a sweat.

On top of that, it dries quite fast and can be recoated in just one hour. And the best part is that you can apply as many as 3 coats per day without the need for sanding between coats. 

Now, the major issue with varnishes is that they often fail to maintain the finish due to temperature changes and humidity. But this product will come to the rescue as it contracts and expands with the wood during seasonal changes, thereby maintaining the finish of the surface. 

It is available in both satin and gloss; therefore, you have the option to choose a finish that would best meet your requirements. Overall, one of the best car shines that any DIYer can hope to get their hands on.    

According to some customer reviews, the cleanup requires applying toxic solvents like xylene and can’t be done with just soap and water. So, make sure that you are careful. Other than this, it is a quality option available at a reasonable price.  

6. General Finishes Exterior

General Finishes is among the leading manufacturers of innovative water-based finishes in the US. As such, it should come as no surprise that Exterior 450 from the brand is one of our top recommendations. It offers a durable coating that helps keep wooden surfaces free from damaging elements.     

The best part about this product is that it is fortified with UV absorbers, which help protect and stabilize the integrity of the coating. Plus, it features built-in mildewcides that prevent the growth of mildew and mold on wooden surfaces, thereby adding to the durability of the surface. 

Furthermore, it is easy to apply. In fact, this product can be rolled, sprayed, or brushed on surfaces at the user’s convenience. It offers a clear-drying finish that can be applied on a wide range of exterior surfaces, including entrance doors, patio furniture, fences, and a lot more. 

We also loved the fact that it is available in quantities of 1 gallon and 1 quart, allowing you to choose a size based on the project’s requirements. From our experience with this product, we are sure that you’ll be more than happy with its results.  

This product is undoubtedly an outstanding choice, given its versatility and durability. But having said that, the only gripe we have against it is the steep price tag, which may be beyond the buying capacity of most paint enthusiasts who are starting new.  

7. Deft 037125257040

Are you looking for a premium polyurethane that provides superior protection to both interior and wooden surfaces? Then the 037125257040 from Deft will work out perfectly well, as it comes with a hoard of benefits that ensure you get spectacular results. Want to know more about this product? Well, then keep reading. 

Being water-based, it offers a clear protective topcoat that is formulated with the latest urethane technology. This ensures that your surfaces are equipped with superior UV protection, thereby providing top-notch weather resistance and durability. Plus, you can apply it to a range of exterior and interior surfaces. 

Eco-conscious users will especially love this product as it meets environmental regulations for VOC, thereby eliminating the short and long-term health risks of using polyurethane. Not to mention, it has a low odor, which in our opinion, is a bonus. 

We also loved the fact that this product can be applied through a spray gun, which is handy when you have many projects to deal with. Finally, all these benefits make this product one of the most sought after polyurethane solutions by professionals.   

Much like the Rust-Oleum 207008, it tends to add a slight tinge of yellow on white-colored surfaces. Even though this might be an issue for all, it surely is a disappointment for those who don’t want their white-colored wooden surfaces to turn yellow with time. 

8. Deft ‎037125020040

Next, we have included another Deft product, and honestly, this list would have remained incomplete without it. The ‎037125020040 Defthane Polyurethane provides an excellent finish on both exterior and interior surfaces and it’s as good as the other options on this list. Obviously, there’s a lot more to it, so keep reading.   

This product is specifically designed to be used in hard-use areas. As such, it has some of the most secure and best finishes for wooden structures. Plus, you would be pleased to know that it is highly versatile, meaning it is suitable for a range of interior and exterior surfaces, including furniture cabinets, doors, and floors. 

Once you apply this product, its formula dries in just half an hour, leaving an eye-catching and robust gloss finish that is resistant to both UV rays and water. This enhances the durability and longevity of the wooden surface to a great extent. 

DIYers venturing their first project will love the fact that it is easy to apply and that they will be the ones in charge throughout the entire process. Overall, it is one of the best qualities of polyurethane on the market that you simply cannot afford to ignore if you want the desired results.      

Even though it has a faster drying time of just 30 minutes, the recoat time of this product is over 6 hours, which is too slow, in our opinion. But other than this, we don’t really have much to complain about this otherwise great product.   

Best Exterior Polyurethanes Comparison Table

Buying Guide for the Best Exterior Polyurethane

Let’s face it, knowing the brand names, specifications, and a few pros and cons is simply not enough when buying the best exterior polyurethane. Since different products have different properties, choosing the right one that would meet your project requirements is easier said than done.

That’s why we have come up with this buyer’s guide, explaining all the key factors that you should keep in mind when selecting an exterior polyurethane. Plus, we strongly advise reading this section carefully to avoid making any mistakes while purchasing.

Ease of Use

You should always go with a product that is easy to apply. This factor is particularly important for DIYers who are starting new. Needless to say, the more your polyurethane is easy to apply, the less professional help you would require. In this way, you can ensure that you are cutting down on the additional expenses required to hire a professional.   

Durability

Durability is one of the essential factors that you need to consider when buying an exterior polyurethane. Your product should be able to offer long-lasting protection to your wooden surfaces against various weather elements. It will help you save expenses on repairs and the time you need to refinish the surfaces.     

Drying Time

The drying time is a crucial factor for professionals who work on projects within a limited timeline. So, if you are one of them, we suggest going with a product that has a fast drying time. In this way, you will be able to complete multiple projects throughout the day.

Finish

Polyurethane solutions come in different finishes, the most common ones being satin, gloss, and clear. Before purchasing, confirm what finish your product offers, as it will determine how your wooden surfaces will look.

Flexibility

You might already know that wood expands and contracts due to changes in weather conditions. As such, it is best to choose an exterior polyurethane that features the right amount of resins and oils to enable the coating to expand and contract with the wood. So, make sure you check the specifications for flexibility before making a decision.

Resistance to UV Rays

Truth be told, polyurethane solutions that offer a clear finish are usually not as long-lasting as other finishes. Since the clear coating allows the wooden surface to be visible, naturally, it makes the wood not as protected from the sun’s harmful UV rays. So, achieving quality protection for a surface that has a clear finish is a bit complicated. 

Therefore, you should ideally go with a product that features titanium dioxide, as it can reflect the UV rays back. That said, keep in mind that no additive is 100% functional at blocking away the UV rays.       

Oil-based or Water-based

Before you make a purchase, you should have in-depth knowledge of the two most common types of polyurethane formulas available on the market: oil-based and water-based. 

A. Oil-based Formula

They offer more durability but are a bit more expensive than water-based polyurethane. They are the ideal choice for exterior wooden surfaces as they offer top-notch protection from harsh weather elements. Plus, oil-based formulas contract and expand with the wood, which further adds to the durability. 

B. Water-based Formula

Polyurethane featuring water-based formulas is popular for showcasing the natural finish of wooden surfaces. They protect the wood from drying out by offering enough hydration and enhancing the overall beauty of the surfaces.    

What should I consider when selecting an exterior polyurethane?

When selecting an exterior polyurethane, there are several key factors to consider. These include ease of use, durability, drying time, finish options, flexibility, resistance to UV rays, and whether it is oil-based or water-based.

How important is durability in an exterior polyurethane?

Durability is crucial because you want your polyurethane to offer long-lasting protection against weather elements. A durable product will save you time and money on repairs and refinishing in the long run.

Why is flexibility important in an exterior polyurethane?

Wood expands and contracts with changes in weather conditions. To prevent cracking or peeling, it’s important to choose a polyurethane that has the right amount of resins and oils to accommodate this movement. Check the specifications for flexibility before making a decision.

What are the differences between oil-based and water-based exterior polyurethane?

Oil-based polyurethane offers more durability and protection against harsh weather elements. It expands and contracts with the wood, enhancing its durability. Water-based polyurethane, on the other hand, showcases the natural finish of wooden surfaces and provides hydration to prevent drying out.

Conclusion

So, that brings us to the end of our review-based guide; hopefully, it will help you make an informed purchase. 

But before we drop the curtains, let us tell you about our top picks from this list. The Rust-Oleum 250041H is a good choice if you are looking for a product that can be used on a wide variety of surfaces and has a low odor. 

Closely following it is the Minwax, mainly because it offers a crystal clear finish and sports an affordable price tag. However, if you are looking for an item that offers a durable coating and that is specifically designed for boats, we suggest going with the Rust-Oleum 207008.

On that note, it’s a wrap. Until next time, take care!  

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