Furnishing wood with polyurethane is a great way to accentuate its natural glow and appearance without affecting the color. It also provides protection from the elements. Most exterior polyurethanes have UV blockers and water-resistant properties.
Unfortunately, not every product is created equal. Even though all brands claim to deliver a stunning finish and maximum protection for all wood surfaces, not all of them live up to expectations.
But not to worry, we will help you avoid the hurdle of sorting through myriads of products. After much research and testing, we’ve rounded off the best polyurethane for outdoor wood furniture on the market today. What follows are ten products with exceptional durability and easy application step.
Without wasting any more time, let’s begin the journey!
What is Polyurethane?
Polyurethane is essentially a form of varnish, extremely tough, and formulated as microscopic chains of resin molecules that bond together firmly as it dries. This creates a finish far superior to traditional varnish in terms of resilience and resistance to abrasion, water, and solvent.
Some polyurethane products have oils in them that leave behind a warm, amber tone on wood. But if you prefer to maintain the light color of the wood, then opt for a water-based polyurethane.
You will also find polyurethane in different styles or finishes. These include satin, gloss, and semi-gloss. Amongst these, satin is the least reflective, while a high gloss finish reflects the most light.
Is polyurethane good for use in outdoor furniture?
Yes, polyurethane is great for outdoor furniture. It provides one of the toughest finishes and is exceptionally durable. More so, it’s waterproof and won’t fade or rot like some wood finishes. So, you can favorably apply it to outdoor furniture and decks.
However, it’s vital you choose the right type of polyurethane. This is because the product is available in two categories – interior and exterior polyurethane. While exterior polys can be used indoors and outdoors, interior polys are only suitable for indoor use, mainly because they lack the UV protective shield present in exterior polys.
So, before making any purchase, be sure to check the label on the container to confirm it’s for outdoor use.
How to Choose the Best Polyurethane for Outdoor Furniture
There are a few things you need to consider when purchasing the best exterior polyurethane paint. Let’s go over them.
One of the first things you should consider when choosing your polyurethane paint is the drying time. This refers to how long it takes for the paint to dry. Whether or not you opt for a fast-drying formula depends on the urgency of your project. If you have a tight deadline, then you want something that will dry within a few hours or cure completely in a day. Or else, the drying time doesn’t matter much as long as you don’t have to wait for the whole week.
Water-based polyurethanes generally dry faster than their oil-based counterparts.
Another thing you should look at when selecting an outdoor polyurethane is its durability or endurance. You don’t want a product you will have to reapply every three months or so.
Generally, most polyurethanes are durable, but some still perform better than others. You want something that will last for a long time so you won’t have to refresh the surface frequently. This way, you will be saving time and money in the long haul.
For products that are a bit thin, you may need to apply more coats to get the desired results.
Ease of Use
If you’re a beginner, you must choose a product that is easy to use, or you might make a mess of your project. Normally, you will find instructions on how to use the product on the label. You will most likely need a spray gun or some other instrument to produce the best results. A few polyurethane may need to be painted.
In any case, if you’re not sure you can take on the project on your own, then it’s best to hire a professional.
Oil-based polyurethanes have a high VOC profile and may have a strong smell. So, if you’re someone who is highly sensitive to strong chemical smells, then this type of poly might not be right for you. Though, this doesn’t apply to all brands.
Water-based polys generally have lower VOCs and do not have strong smells.
Regardless of the product you choose, you may need to wear some protective gear. Also, choose an aerated place to work, even if you’re using a water-based finish.
Top 8 Best polyurethane for outdoor furniture
1. Minwax Fast-Drying Polyurethane Protective Wood Finish
The Minwax Fast-Drying Polyurethane is an oil-based poly for sealing both finished and unfinished wood. It provides a semi-gloss finish that adds long-lasting beauty to wood pieces.
Unlike some products, it doesn’t darken the wood grain too much but leaves a clear top coat that protects the wood from scratches and spills. The gloss looks very nice, not too shiny but sleek and attractive. It’s hard not to notice the sheen.
You can choose either spray paint or brush paint to apply the product to outdoor furniture. We recommend using a bristle brush as that would give you the best results. Avoid sponge brushes as those can create bubbles. You can also use a rotating spray can to avoid drips and sags. The good thing about using a spray can is that you don’t need to clean it up afterward; just toss the can in the trash.
Remember to stir the paint; don’t shake it to avoid creating bubbles.
It takes about 4 to 6 hours for the paint to dry before recoats, which is impressive for an oil-based finish. So you can complete your projects faster. You can apply it using a spray, roller, or brush.
Overall, the Minwax Fast-Drying Oil-based formula is a great deal for the price and quality. It is easy to use and guarantees long-lasting protection on outdoor wood surfaces (both finished and unfinished).
- Gives wood a modern look
- Reasonable pricing
- Removes stains on unfinished wood
- Easy to use
- Available in different sizes
- Suitable for all kinds of wood
- Has a weird smell
- Takes time to cure fully
2. Minwax Helmsman Indoor/Outdoor Spar Urethane
The Minwax Helmsman Spar Urethane is another great option for homeowners or painters on a strict budget. As the name suggests, it is formulated for indoor and outdoor use and will work for all wood pieces, including furniture, doors, woodwork, and others.
Besides the low price point, the product comes in a gallon, which provides more value than a quart-size can. You’re basically paying less per quart.
The main reason we love the product is that it’s designed for heavy use. It creates a protective yet attractive crystal clear finish that can withstand the worst weather. Specifically, it features a blend of UV inhibitors for sun protection and to prevent yellowing and flaking of wood. The protective barrier also resists moisture and dirt.
The formula also contains special oils that help it handle rapid temperature changes by contracting and expanding with the wooden surface. This ensures no real damage is done during harsh weather conditions.
Drying is quick, and you won’t have to wait too long between coats. However, it takes about 24 hours for the finish to dry completely before you can use the item.
Unfortunately, with a quick-drying formula, you don’t have much time to make corrections. If you put a brush on the coating after it begins hardening on the wood, you will have to sand down the wood surface and start all over again.
In case there are holes or cracks in the wood, fix it a wood grain filler before applying the coating.
It is worth mentioning that the coating is thin (watery) and tends to soak into porous surfaces. As a result, you will need to apply multiple coats to achieve the desired result.
- Provides great value for your money
- Gives a crystal clear finish (it doesn’t affect the wood color)
- Contains UV blockers
- Dries quickly
- Adapts easily to rapid temperature changes
- Resistant to moisture and dirt
- A bit watery
3. General Finishes High-Performance Water-Based Topcoat
As the name suggests, the High-Performance Water-Based Polyurethane by General Finishes is a go-to finish for almost everything. And you can use it over paint and stain. We must confess that it’s a bit pricey but well worth the cost.
Besides cost, our preference for the product is mainly linked to its look, durability, and simplicity of application. It’s an “A-class” polyurethane and thus provides the toughest shield for a wooden surface. It is also long-lasting and can be used both for home and commercial projects.
The sealant is water-based, so you don’t have to worry about hard clean-ups or yellowing. It has UV blocking and water resistance, so it’s perfect for outdoor use. It also protects wood against dents, marks, and scratches.
As earlier indicated, the product is super easy to apply with a sponge brush. It dries quickly and levels out perfectly while tightening beautifully. The resulting finish has a mild sheen that resembles nice polished wax. Besides the satin finish, it is also available as gloss, flat and semi-gloss finishes.
Depending on the project and wood type, we recommend 3-4 coats. Ideally, you want to sand (lightly) between the first two layers to ensure you get the perfect finish. But you don’t really need to be a perfectionist to get a great finish.
- Doesn’t cause yellowing
- Super durable finish
- Has UV and water resistance
- Super fast drying
- Easy to clean
- Low odor
- It tends to be drippy (make sure you put something underneath)
- Not recommended for white surfaces such as chalk or milk paint
4. RUST-OLEUM 9231 Ultimate Spar Urethane, Oil-Based
The Rust-Oleum Ultimate Spar Urethane is another hard, durable polyurethane coat on the market today. It has three singular properties that make it attractive – it’s super affordable, resistant to mold, and can withstand any weather condition. This makes it perfect for any exterior furniture.
It’s arguably the best outdoor polyurethane for its price. So, you can expect the best value for your money.
Talking about its efficacy, it is formulated to resist UV damage, which is expected of any good polyurethane. It also helps to prevent mold and mildew growth, which should come as a big release considering how unpleasant it can be to remove such stains. Being oil-based also means it will resist water, and that is due to the hydrophobic nature of oils. So exterior wooden surfaces sealed with the product can be left in the rain, fog, and other extreme conditions.
Once applied, it leaves behind a shiny, durable finish with a beautiful satin look.
Also, the coat has a quick-drying profile. Unlike most oil-based finishes, it dries in as little as 2 hours, and recoating can be done after 8-9 hours. However, you should wait at least 1-3 days before using the item.
Overall, we are impressed with the quality of this polyurethane. Although you have to wait 8 hours between each coating, it leaves behind a weather-resistant and long-lasting finish. Perhaps, considering the price, it’s hard to complain.
- Gives a natural satin finish
- Easy to work with
- Great value for your money
- Provides UV and water protection
- Mold and mildew resistance
- Adapts to rapid weather changes
- Can take up to 8 hours between recoats
5. Rust-Oleum 250241H Ultimate Spar Urethane
The Rust-Oleum 250241H Ultimate Spar Urethane will make an excellent choice for people who prefer a water-based formula. But besides its water-based properties, the Rust-Oleum 250241H is one of the most eco-friendly options. It is nearly odorless, non-toxic, and doesn’t cause yellowing, making it perfect if you have kids or pets around. Even more, it delivers an excellent long-lasting weatherproof finish.
As earlier indicated, this is water-based, which means it comes with all the perks of a water-based formula. This includes fast-drying, easy clean-up, no weird smell, and easy application.
Specifically, it dries to touch in as low as 30 minutes, covering up to 87 square feet per quart. It usually starts out white but dries to a crystal clear, satin finish giving your wood a classic, natural look. The coating is a little thin, so you may need to apply it multiple times. Recoat should be done after 2 hours.
We suggest getting 3-4 coats for optimum protection, which can be achieved in a day. Then allow the wood piece to cure for 24 hours. It’s worth noting that the product is a bit runny, so you have to watch for drips, especially in the first 20 minutes before it dries and hardens. However, if the drip dries, you can smoothen it down with fine-grit sandpaper.
Also, we suggest using a spray rather than a roller or brush since the polyurethane is a bit light. Stir well and avoid shaking it to prevent bubbles.
As earlier indicated, the smell is barely noticeable, so you can use it indoors without any problem.
Again, since the product doesn’t cause yellowing, it can go on any type of wood. Like the other polys on the list, it has UV blocking and water resistance. It also prevents mold buildup as well as cracks and scratches while delivering a beautiful appearance.
Overall, even though this polyurethane formula is a bit expensive, it’s well worth it. It’s one of the safest options that thrives on outdoor furniture. We cannot recommend it enough!
- Provides long-lasting protection
- Easy to use and clean
- Low odor formula
- Gives a crystal clear satin finish
- Doesn’t cause yellowing of wood
- Thin (requires multiple coats)
- A bit costly
6. Deft Interior Exterior Water-Based Polyurethane Finish
The Deft Interior Exterior Water-Based Polyurethane is a perfect match if you want a sealant you can use for both indoor and outdoor projects. It’s one of the best options for solid wood and provides greater durability than most oil-based polys.
The formula is 100 percent urethane and uses the latest modified technology. It contains UV protection which keeps wood from fading and disintegration. It also has a waterproof shield that repels moisture and dirt, making it suitable for all-year protection. Besides furniture, you can also apply it on boats, kayaks, and other marine items.
The product is low odor and meets the environmental regulations for VOC. So, you don’t have to worry about inhaling toxic fumes or irritants. It’s so easy to clean up with soap and water, which is not surprising since it’s water-based.
We also love that it is self-priming and doesn’t require a sealer, which saves you time and energy. It is also easy to apply with a brush, pad, or spray.
It is fast drying, and recoating can be done in just two hours. This way, you can apply extra coats with light sanding to get a tougher finish. The coating dries clear and doesn’t affect the color of the wood or cause yellowing.
The product is available in gloss finish and comes in a 1-quart container.
Overall, we think the Deft Interior Exterior Polyurethane will make an excellent choice for anyone not bothered by the price. It goes on easy, dries quickly, and is non-toxic. More importantly, it gives a nice level finish that is sleek and attractive and can be used on interior and exterior surfaces. It comes highly recommended!
- Superior UV protection
- Low odor and VOC profile
- It can be used both indoors and outdoors
- Fast drying
- Gives wood a sleek and attractive look
- Easy to apply
Some people may find it a bit pricey
7. ZAR ZAR-34112 Ultra-Fast Drying Exterior Polyurethane
The ZAR Ultra Fast Drying Formula is perfect for homeowners who want a polyurethane with superior UV protection. It’s formulated with antioxidants and UV radiation absorbers, making it ideal for exterior surfaces subjected to direct sunlight or rapid weather changes.
Although the formula is oil-based, it is incredibly fast-drying. In fact, it dries in just 2 hours which is a big plus, especially if you have a tight deadline. It goes on nicely and gives a clear satin finish with a beautiful antique look and no milkiness. This makes it perfect if you want something that will give a beautiful finish without leaving a lot of shine or residue.
We suggest using a natural bristle brush to prevent or minimize brush marks. A sprayer might work better, but you must thin it with mineral spirits or any other paint thinner. A little sanding between the first two coats is recommended to give a smoother finish.
Also, be sure to stir the product well before using it. This helps to dissolve any sediment that might be laying at the bottom.
Overall, we are satisfied with the quality and performance of this polyurethane. It’s very professional and provides superior protection from the weather. It doesn’t change the wood color and goes on easily. More importantly, it works for both outdoor furniture and marine surfaces located above the water line. This makes it one of the best exterior polyurethane available.
- Superior protection against sunlight and harsh weather
- Professional satin finish (clear and natural)
- Goes on easily
- Very affordable
- Super fast drying (only 2 hours)
- Suitable for wooden marine surfaces
Shell life is fairly short
8. TotalBoat Gleam Marine Spar Varnish, Gloss, and Satin
Lastly, we have the TotalBoat Gleam, a classic marine spar varnish that leaves behind a beautiful, transparent hue suitable for all types of wood. The formula contains premium tung oil and phenolic resins responsible for its transparent amber finish. It is waterproof and has good UV protection. So, you can use it on both interior and exterior wood, including garage doors, kayaks, boats, and outdoor furniture. It holds up well in the hotter months, but we still recommend using a tarp or some other cover to ensure it lasts longer.
The product is easy to apply. And that is mainly because it’s thinned right out of the can. So, you can do several thin coats instead of just one heavy application. Most projects will require at least four coats. We suggest light sanding after the first coat to get a smoother finish. You can use a brush, roller, or sprayer.
It’s also recommended to thin with 20 to 25 percent mineral spirits or some other paint thinner. You can apply with a brush, roller, or paint gun. The good thing about the formula is that it glides on smoothly and doesn’t leave behind any line of bubbles.
The product is fast drying and self-leveling. Recoats can be done in an hour at 72 degrees Fahrenheit, which means you can apply up to 3 coats in a day. The resulting finish looks very glossy and lays flat. It’s also flexible and will expand and contract with the wood during rapid changes in temperature or humidity. Again, we recommend doing 4-6 coats to get a sleek, long-lasting finish.
The product is available in gloss or satin finish. For the best results, you can build with the gleam gloss and finish off with satin. You will also find it in quart and gallon sizes. A gallon can cover around 250 square feet.
- Easy to clean up occasional stains
- Easy to use
- Super durable
- Features UV inhibitors
- Fast-drying formula
- Provides good coverage
- Has a strong smell
- A bit pricey
Water-Based vs Oil-Based Polyurethane for outdoor furniture?
There are two main categories of polyurethane. These include oil-based polyurethane and water-based polyurethane.
This type of polyurethane has a milky appearance initially but dries to a crystal clear finish. It’s a great option if you want to preserve the natural color and beauty of wood.
It tends to be watery and, as such, often requires you to apply multiple coats, more than an oil-based polyurethane. But it dries faster and is less damaging to the environment. It is also easier to clean with soap and water.
Although the VOC profile in water-based polyurethanes is lower than their oil-based counterparts, it’s still recommended to use them in a well-ventilated area.
An oil-based polyurethane is more durable and adds warmth to the wood surface. Instead of a crystal finish, it leaves a slightly amber color when dried, which looks more pleasing, especially on natural woods. Even though it provides a more durable finish, it is usually less expensive than water-based polyurethanes.
Unlike water-based polyurethanes, you can attain a tough finish with just 2-3 coats of an oil-based polyurethane. However, it takes much longer to dry, so you will have to wait longer between coats. Also, it has a higher VOC level, so you need to work in a well-ventilated area and use protective equipment.
Oil-based polys are also harder to clean. You will need mineral spirits or acetone rather than just soap and water.
If you have to choose between both polys for your outdoor furniture, we advise you to choose oil-based polys for floors that get a lot of foot traffic or items that take a lot of abuse from the weather. A water-based polyurethane will be better if you want to maintain the wood’s natural color or grain.
Will Polyurethane Make Wood Furniture Waterproof?
No, it won’t. Polyurethane doesn’t make wood waterproof, but it will make it water-resistant. This means the wood surface will be able to repel water and won’t get soaked when it rains.
So, coating your wooden furniture and floors is a good way to protect them from moisture. But like we said earlier, the wood won’t be completely waterproof, which means it can still get wet, though not to the point of causing any damage.
Is Polyurethane Better Than Varnish For Outdoor Application?
Not really. Polyurethane may be better for hardwood floors, but for most outdoor projects, varnish still has the upper hand when it comes to natural durability and UV protection. This is because, unlike polyurethane which could be oil- or water-based, wood varnish consists of resins, oils, and solvents. This makes it better suited for outdoor weather.
However, polyurethane offers more flexibility in the sense that it can be used for both indoor and outdoor projects. Varnish, on the other hand, is only suitable for exterior surfaces.
Generally, both finishes offer durability and protection from the elements. They are also available in various color options.
Can you put polyurethane on outdoor furniture?
Yes, you can. In fact, polyurethane gives one of the best exterior finishes and is exceptionally durable as long as you choose a product with the right ingredients, such as additives for protection from UV light. It’s normally stated on the label whether the product is for interior or exterior use.
Do I Need to Seal Wood Before Applying Polyurethane?
Not really. Most polyurethanes don’t require you to seal the wood before applying them. But if you’re going to use a sealer, make sure it’s compatible with the polyurethane. Alternatively, you can opt for a penetrating resin sealer to finish off the wood completely. Then, you can follow up with polyurethane on top to get a smoother finish.
What is the best waterproof finish for outdoor furniture?
To be honest, there’s no such thing as the best waterproof finish for patio furniture. This is because factors such as your budget, the wood type or project, skill level, and needs will determine which finish or sealant will suit you best. In any case, polyurethane, lacquer, and varnish are three of the most common options for clear coat sealers.
Can water-based polyurethane be used outside?
Yes, it can. In fact, many people prefer using water-based polyurethane on their outdoor projects because they are easier to apply. However, be sure the product has the right ingredients. More importantly, it should contain UV blockers if it’s going to be used outdoors.
Can I use interior polyurethane outside on a wood surface?
No, this is not recommended. As the name suggests, interior polyurethanes are specifically formulated for indoor use, which means you can only use them on interior surfaces. Unlike exterior polyurethanes, they lack UV protection which makes them unsuitable for outdoor use. We have some indoor-outdoor polyurethane that you can use both indoors and outdoors.
Can you use exterior polyurethane inside?
Yes, you can. Most exterior polyurethanes are versatile and can be used on both indoor and outdoor pieces. But, you should never apply interior polys on outdoor furniture. This is because, unlike exterior polys, they don’t contain resin or additives to absorb UV rays.
What is the best way to seal outdoor wood furniture?
The best way to seal outdoor wood furniture is to use a waterproofing agent. These could be a natural oil like tung oil or linseed oil or a clear coat sealer such as polyurethane or varnish. A stain-sealant combo will also work fine.
Can oil-based polyurethane be overcoated with water-based?
Yes, you can overcoat oil-based polyurethane with water-based polyurethane, but the conditions must be right. First, the wood surface must be prepared correctly by removing any residing dirt, wax, or grease. You can use a deglosser or wood cleaner. Mineral spirits will also work fine.
What is the best polyurethane for exterior doors?
All the products on the list can be used on exterior doors. But we personally prefer the Marine Spar Varnish or Minwax Helmsman Spar Urethane. Either of these polyurethanes provides great protection for exterior doors and are in different finishes.
As you can see, polyurethane is a great finish for outdoor furniture. Not only does it provide protection, but it also helps to maintain the aesthetics and natural color of the wood.
Overall, our favorite polyurethanes are the Minwax Fast-Drying Oil-based formula and the Rust-Oleum 9341. Although both polys are oil-based and take longer to dry, they are exceptionally durable and offer the best protection against moisture, sunlight, and mold.
You can also consider the Deft Exterior/Interior Polyurethane if you prefer a water-based finish. It has a smaller coverage but also offers great resistance to the elements.
Generally, you won’t go wrong with any product on the list as long as it aligns with your needs.
Let us know if you have any more questions about choosing the best polyurethane for outdoor furniture. Until then, happy sealing.