Best Exterior Polyurethane – [Reviews & Guide 2022]

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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.

  1. Overall Best Exterior Polyurethane: Rust-Oleum 9341
  2. Best Water Based Exterior Polyurethane: General Finishes Exterior 450 Water Based Topcoat
  3. Best Exterior Polyurethane for the Money: Minwax 63200444 Helmsman Spar Urethane
  4. Best Exterior Polyurethane For Marine Use: TotalBoat Gleam Marine Spar Varnish
  5. Best Eco-friendly Exterior Polyurethane: Rust-Oleum 250241H Ultimate Spar Water-Based Urethane
  6. Best Exterior and Interior Polyurethane: Deft Interior Exterior Water-Based Polyurethane Finish
  7. Best Exterior Polyurethane for Extreme Weather: ZAR 34112 Ultra Fast Drying Exterior Polyurethane

1. Rust-Oleum 9341 Ultimate Spar Oil Based Exterior Urethane – Overall Best Exterior Polyurethane

The Rust-Oleum 9341 Ultimate Spar Oil Based Urethane comes with three singular properties that allow it to stand out as the overall best exterior polyurethane. Its superior UV protection, mold, and mildew resistance, as well as waterproof finish, make it perfect for any outdoor surface.

The Rust-Oleum 9341 exterior polyurethane features an oil-based formula. Thanks to this formulation, it guarantees a more even, shinier, and durable finish. Packed with its three key protective environmental features, the polyurethane protects outdoor wood surfaces with increased precision. Its innovative formula allows it to dry quickly in as low as just 2 hours; covering an area of up to 190 square feet. Furthermore, its quick dry profile allows recoating in just after 9 hours.

  • The oil-based formulation gives it a satin feel and natural look
  • Adapts to weather changes
  • Fast drying profile allows for quicker recoating
  • Offers a waterproof finish as well as mold and mildew resistance
  • The finish is somewhat glossy


Q: Can I Use This Polyurethane on Metal Items?

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

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

A: 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.

2. 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 ecofriendly, 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 topcoat – you simply need soap and water
  • UV absorbers maintain the color and durability of the coated finish
  • Water-based formula is safer and ecofriendly
  • Causes yellowing when applied to a white or light colored surface


Q: How Do I Apply This Topcoat?

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

Q: Can the Topcoat Use it For Interior Items?

A: 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.

3. Minwax 63200444 Helmsman Spar Urethane – Best Exterior Polyurethane for the Money

If you are on a strict budget, the Minwax Helmsman Spar Urethane is what you need. Nevertheless, it offers a protective yet, attractive barrier for furniture, woodwork, doors, and other similar accessories.

Featuring a blend of UV absorbs, the Urethane still maintains excellent protection from the sun. Thanks to this UV protection, you don’t have to worry about fading on your items. Furthermore, the urethane is formulated to deliver a protective barrier against rain, water, moisture, and dirt. Thanks to this finish, your wooden items will always look as good as new and maintain unmatched durability. In the event of rapid temperature changes, the urethane contracts and expands with the wooden surface to match the weather needs without any damage.

  • The urethane can be used both indoors and outdoors
  • Formulated to create a protective layer against moisture, rain, and dirt
  • Easily adapts to rapid temperature changes – both cold and hot
  • Contains UV absorbers to protect against sunlight and fading effects
  • Not the best options for items made out of wood


Q: Can The Polyurethane Work on Materials Other Than Wood?

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

Q: How Long Does It Take To Dry?

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

Overall Impression

The Minwax Urethane doesn’t only come with the advantage of being cost-effective and affordable. Thanks to the superior formulation it gives you value for your money. Its protective barrier against rain, moisture, and dirt helps to give the coated surface longer lasting durability and functionality.

4. TotalBoat Gleam Marine Spar Varnish – Best Exterior Polyurethane For Marine Use

Designed for water vessels, wood, and outdoor furniture, the TotalBoat Gleam Marine Spar Varnish is perfect for marine applications. Its UV protection and quick drying formula help to boost its durability whether you apply it on water vessels or dry furniture.

Treated with waterproof and UV inhibitors, the TotalBoat Gleam exterior polyurethane can be applied on items ranging from boats, kayaks, canoes, and even, outdoor wooden furniture. Formulated with self-leveling and quick drying profile, this wood varnish allows recoats in as little as an hour. You can even apply up to 3 coats within a day. Yet, thanks to its innovative curing, you don’t have to worry about damages during rapid temperature changes. The varnish easily expands and contracts with the wood surface on humid and colder days, respectively.

  • Comes in a choice of gloss or satin finish
  • Quick drying formula allows you to apply up to 3 coats within a day
  • Formulated with premium Tung oil, phenolic resins, and UV inhibitors to cover all types of interior and exterior wood
  • Expands and contracts with the wood surface according to the weather changes
  • It is somewhat costly


Q: How Much Area Does The Polyurethane Coat Cover?

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

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

A: 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.

5. Rust-Oleum 250241H Ultimate Spar Water-Based Urethane – Best Eco-friendly Exterior Polyurethane

The Rust-Oleum Water Based Urethane’s low odor and non-yellowing formula makes 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 of 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, the urethane is specially formulated for exterior furniture as it holds outdoor thriving properties. Thus, it is not advised to use it for interior furniture.

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 ecofriendly 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.

6. 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 means 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 the 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 the 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.

7. 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


Q: Should I Thin the Polyurethane Before Application?

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

Q: How Much Area Does the Polyurethane Cover?

A: The polyurethane covers up to 150 square feet 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.

Comparison Table

Product NameCoverage (Square Feet)Recoat Dry(hours)Type
Rust-Oleum 9341

(Editor's Choice)
1908satin, gloss, semi-gloss
General Finishes Exterior 450
140-1602+satin, gloss, semi-gloss
Minwax 63200444
TotalBoat Gleam Marine Spar Varnish
Rust-Oleum 250241H
1872satin, gloss, semi-gloss
ZAR 34112


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 the 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.