Best Exterior Polyurethane – [Reviews&Guide 2023]

If you want to improve your outdoor furniture without altering its surface look, we have just the solution for you. What you need is the best exterior polyurethane. When applied to the surface, polyurethane offers a clear finish, thus, bringing out the look of your wooden furniture. The clear finish accentuates its glow and natural appearance without affecting its color.

Furthermore, exterior polyurethane contains a flattening agent that naturally reduces increased glow and tackles UV radiation. Thanks to this natural agent, exterior polyurethane delivers a long-lasting coat. To help you find the best options in the market, we’ve compiled the 7 top-rated exterior polyurethane options for this year. Take your pick of the ultimate choice for your home.


Minwax Helmsman Spar Urethane

Our’s Top Choice

Minwax Helmsman Spar Urethane is a clear, protective finish that is specifically formulated to resist the damaging effects of sunlight, water, and temperature changes on wood. It provides long-lasting protection against fading, yellowing, cracking, and peeling, and it will not cloud or dull your finish. Minwax Helmsman is available in three different finishes so that you can choose the perfect look for your needs.

What I love most about Minwax Helmsman is its ability to protect against the sun’s harmful UV rays, which can cause wood furniture to deteriorate over time. With Helmsman, your furniture will remain looking great year after year. Additionally, it has a long lifespan compared to other finishes, meaning it won’t discolor or fade over time. Plus, it’s water-resistant, so you can use it both indoors and outdoors without worrying about the elements damaging your furniture.

I put Minwax Helmsman Indoor/Outdoor Spar Urethane to the test by painting a piece of wood and then exposing it to direct sunlight and different weather conditions. I kept track of how well the urethane protected the wood from discoloration, cracking, and peeling. The urethane did an excellent job overall, and we were very pleased with the results. I would definitely recommend using Minwax Helmsman Indoor/Outdoor Spar Urethane on your next woodworking project.

  • Indoor & outdoor use
  • Protects against moisture, rain, & dirt
  • Adapts to rapid temperature changes
  • Contains UV protection against sunlight & fading
  • None noted

Can The Polyurethane Work on Materials Other Than Wood?

It depends on the material. Urethane can easily work on materials with properties that are almost similar to that of wood, for example, resin or acrylic.

How Long Does It Take To Dry?

You should wait for at least 24 hours to ensure it dries before you start using any item coated with this urethane.

overall impression
Minwax Helmsman Spar Urethane is an exceptional product that I highly recommend to anyone searching for a top-quality clear protective finish. Applying the urethane is simple, it does an excellent job of protecting wood surfaces from harm caused by exposure to the elements, and leaves the original finish unchanged.

TotalBoat Gleam Marine Spar Varnish

Best Exterior Polyurethane For Big Projects

I recently had the chance to try out TotalBoat Gleam Marine Spar Varnish on my backyard furniture and I must say, I was thoroughly impressed with its performance. This varnish is specifically formulated for marine use, providing long-lasting protection against the harsh effects of saltwater, UV rays, and other environmental factors.

One of the things I liked most about TotalBoat Gleam Marine Spar Varnish is how easy it was to apply. It goes on smoothly and dries relatively quickly, without leaving any streaks or bubbles. I also appreciate the fact that it can be applied by brush, roller, or spray, giving me a range of options depending on the project at hand.

What really sets TotalBoat Gleam Marine Spar Varnish apart, however, is its durability. Even after several months of exposure to the sun, rain, and other elements, the finish on my backyard furniture still looks great. It hasn’t faded, peeled, or cracked, which is a testament to the quality of this product.

Overall, I would highly recommend TotalBoat Gleam Marine Spar Varnish to anyone looking for a high-quality varnish that can stand up to the harsh environment. It’s easy to apply, durable, and provides long-lasting protection against the elements, making it a great investment for any boat owner.

  • Gloss or satin finish options
  • Dries quickly; up to 3 coats per day
  • Premium Tung oil, phenolic resins, and UV inhibitors for all wood types
  • Adapts to weather changes, prevents cracking or peeling
  • It is somewhat costly

How Much Area Does The Polyurethane Coat Cover?

This wood varnish covers an area of up to 250 square feet

How Much of the Exterior Polyurethane Should I Apply on clean Wood?

As a general rule of thumb, you should apply 2 to 3 coats of polyurethane.

Overall impression
Thanks to its incredible UV inhibitor and waterproof treatment, the TotalBoat Varnish guarantees long-lasting durability and a look of class on your equipment. Its smooth formula also makes it easy and convenient to apply on any surface whether it’s wooden furniture or a fishing kayak.

I recently had the opportunity to use Rust-Oleum 9341 Ultimate Spar Oil-Based Exterior Urethane for a project and I must say that my experience was quite mixed. As mentioned in one of the reviews I came across, the product is quite thick on the brush and can be difficult to level out. However, I did find that it was relatively easy to apply with minimal brush marks, and it did not dry too quickly, allowing me to work with it for a decent amount of time.

I applied three coats of this urethane over a stained finish and the results were quite pleasing. The first coat did not have an even sheen, but the final coat looked fantastic with a very even satin gloss. That being said, it is important to note that the product did take a while to fully cure, even after being exposed to high temperatures for several days.

Overall, I found Rust-Oleum 9341 Ultimate Spar Oil-Based Exterior Urethane to be a decent product. While it does have its drawbacks, it ultimately provided a beautiful finish that I am quite happy with. As always, it is important to thoroughly research a product before purchasing to ensure it meets your specific needs and preferences.

  • Satin feel and natural look due to oil-based formulation.
  • Adapts to weather changes
  • Fast drying profile allows for quicker recoating
  • Offers waterproof finish, mold, and mildew resistance.
  • The finish is somewhat glossy

Can I Use This Polyurethane on Metal Items?

Yes, thanks to its somewhat thick consistency. This exterior polyurethane can be applied to metal items such as steel.

For How Long Do I Wait Before I Can Use The Coated Surface?

For light use, you want to wait for at least 24 hours. However, for regular use, you want to wait for at least 3 days.

overall impression
If you are looking for the ultimate polyurethane option for optimum protection and long-lasting durability, the Rust-Oleum is what you need. This exterior polyurethane doesn’t only boast an attractive satin and natural finish. Its weather-and-water resistance allows it to provide optimal protection to the surface –whether it’s a piece of furniture, flooring, or railings.

The Rust-Oleum Water-Based Urethane’s low odor and non-yellowing formula make it eco-friendly and non-toxic for home use. For a home with young children or pets, it’s a perfect choice.

Whilst this exterior polyurethane focuses on ensuring safety, it still delivers excellent functionality and durability. Its low-odor formula makes it easy and convenient to apply. Furthermore, the exterior polyurethane’s water-based formula allows it to dry in just 30 minutes whilst covering an area of up to 87 square feet. Additionally, the quick drying profile allows for recoating in just 2 hours. Thanks to its non-yellowing formula, you can apply it to any type of wood. Its weather and UV-resistant topcoat protect against disruptive UV rays whilst preventing mold and mildew build-up.

  • Low odor formula
  • The satin finish is crystal clear and offers a natural look to the wood surface
  • You can apply up to 3 coats in just a day
  • The non-yellowing formula maintains the surface look
  • Its clear color change to milky when it gets wet

Can I Use This Exterior Polyurethane for Interior Furniture?

No, urethane is specially formulated for exterior furniture as it holds thriving outdoor properties. Thus, it is not advised to use it for interior furnishings.

How Do I Apply It?

It is advised to spray this exterior urethane rather than brush it or roll it, as it tends to be a little light.

overall impression
The Rust-Oleum Water-Based Urethane is formulated with eco-friendly properties that allow it to thrive in the outdoors. Whilst it guarantees to add aesthetics to your outdoor furniture and wooden equipment, it still remains to be safe – even if you have young children or a playful pet lounging around.

Deft Interior Exterior Water-Based Polyurethane Finish

Best Exterior and Interior Polyurethane

Formulated to meet environmental regulations, the Deft interior Exterior Polyurethane can be used both indoors and outdoors. Its low odor and VOC profile mean that you don’t have to worry about any toxins or irritants in the air or surface.

Formulated with the latest technology, the water-based urethane offers a surface coating that is twice as durable. Available in a glossy finish, it gives any wooden surface a sleek and attractive look. Its UV protection prevents fading and disintegrating; giving the surface a similar look over prolonged periods. It also features a protective waterproof and dirt-proof barrier for extra preservation. Thanks to this durable formula, you can even use polyurethane for marine applications on items such as boats, kayaks, or canoes.

  • Formulated for interior, exterior, and marine applications
  • Superior UV protection protects the surface against the brightest sun rays
  • Environmental protection offers a barrier against water, moisture, and dirt
  • Offers a 2-hour recoat period
  • It causes yellowing on painted wood surfaces

How Do I Apply This Polyurethane Finish?

You can choose to apply polyurethane through three key methods. These include using a brush, a pad, or an HVLP spray applicator.

Can I Use It on Other Surfaces Than Wood?

No, it is advised against using this polyurethane on materials other than wood.

overall impression
The Deft Interior Exterior Water-Based Polyurethane offers a cost-cutting investment. Using this same polyurethane, you can transform your wooden furniture and equipment without having to invest in multiple brands. Plus, its waterproof, UV-, and weather-resistant finish mean that it will survive any environmental conditions.

ZAR 34112 Ultra Fast Drying Exterior Polyurethane

Best Exterior Polyurethane for Extreme Weather

If you experience extreme weather or rapid weather changes, the ZAR Ultra Fast Drying Exterior Polyurethane is a good choice. The polyurethane is formulated to offer superior protection against extreme weather and UV rays.

The high-quality exterior polyurethane is designed to work with a selection of materials including wood, fiberglass, and steel. You can use it on wooden marine surfaces, exterior doors, and even patio furniture. Although it boasts an oil-based formulation, it still offers a super fast drying function in only 2 hours. Its UV treatment on the other end allows it to protect the surface against UV rays. its ability to adapt to rapid weather changes makes it perfect for the most extreme weather conditions.

  • Can be used on wood, steel, and fiberglass
  • Super fast drying function in just 2 hours
  • Blended with UV absorbers and antioxidants for protection against UV radiation
  • The oil-based formula offers a clear and natural look
  • Marine wooden surfaces should be above the waterline

Should I Thin the Polyurethane Before Application?

Yes, it is a good idea to thin the polyurethane before application – especially if you are using the spraying method.

How Much Area Does the Polyurethane Cover?

Polyurethane covers up to 150 square feet of area.

overall impression
Thanks to its reinforced formulation that protects it against extreme weather, the exterior polyurethane comes with added perks. You can use it on various surfaces such as wood, fiberglass, and steel. Yet, you will still be able to maintain the classy and natural clear look.

General Finishes Exterior 450 Water-Based Topcoat

Best Water-Based Exterior Polyurethane

Integrating built-in mildewcides, the General Finishes Exterior Topcoat prevents slow mold and mildew growth despite being water-based. Thanks to the water-based formulation, this topcoat is eco-friendly, safer, and healthier for your home.

When applied to any surface, the clear satin finish of the topcoat helps to retain the surface’s original color whilst giving it a natural glow. Packed with UV absorbers, the exterior topcoat stabilizes the coated finish whilst protecting the color from sunlight. Furthermore, thanks to the water-based formulation, you will enjoy quicker drying up than you would with an oil-based formulation. However, you should refrain from applying the topcoat on white and light-painted surfaces as this may cause yellowing.

  • Pre-treated formula to prevent mold and mildew build-up
  • Easy to clean up a surface with a topcoat – you simply need soap and water
  • UV absorbers maintain the color and durability of the coated finish
  • Water-based formula is safer and eco-friendly
  • Causes yellowing when applied to a white or light-colored surface

How Do I Apply This Topcoat?

You can choose between three application methods. These include brushing, spraying, or rolling.

Can the Topcoat Use it For Interior Items?

Yes, you can. This polyurethane is water-based; making it a low-VOC topcoat. Additionally, its odorless and toxic-free nature makes it ideal for indoor use.

overall impression
For individuals looking for a safer and environmentally friendly alternative, the General Finishes Exterior Topcoat is an excellent option. Plus, it does more than just offer a safe alternative. Thanks to its ingenious formulation, it adds that layer of shine and class to any wooden surface without affecting its original color.


Exterior polyurethanes offer an excellent way to maintain neat and attractive aesthetics for any outdoor furniture or accessory. After all, exterior polyurethanes are ideally formulated to adapt to outdoor conditions – surviving the rapid weather changes and other environmental factors outside.

Polyurethanes such as the Rust-Oleum 9341 Ultimate Spar Oil-Based Urethane offers great functionality to adapt to the outdoors whilst maintaining longevity. Yet, with the advancing technologies, you are to experience exterior polyurethane that smoothly covers different types of materials other than wood.


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