Exterior polyurethane is one of the most time-tested and trusted wood finishes, and it can be used to strengthen and beautify softwoods, hardwoods, and any wood-based products.
But there are so many exterior polys on the market today—it’s no wonder people often struggle with finding the best one.
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That’s why I put together this list of the best exterior polyurethane you can buy!
In a hurry? Minwax Helmsman Spar Urethane is the best exterior polyurethane overall because it’s a durable, long-lasting, easy-to-use polyurethane that can make wood surfaces look truly stunning.
When it comes to exterior polyurethane, it’s hard to do better than Minwax Helmsman Spar Urethane. It’s a strong, visually appealing, and easy-to-apply product that can be used indoors as well, mainly because it’s less toxic.
A water-based, glossy polyurethane, it can be applied to hardwoods, softwoods, and other materials, but it’s best to refrain from using it on lighter woods, since it does yellow over time.
And since it has UV-blockers, even prolonged exposure to direct sunlight won’t wear it down.
Plus, it’ll hold up year round, as it’s formulated to resist temperature fluctuations. This is big, in my book, since temperature fluctuations wreak havoc on wood finishes and are impossible to predict.
But its ability to seal wood is what distinguishes it as the best of the best; it can rain for days and this poly will stay sound the whole time.
Typically, it’s used on exterior furniture, like deck chairs, tables, and benches. Minwax advises against using this on decks and larger wood surfaces, as it’ll be hard to maintain.
Also, refrain from applying it to the surfaces you walk on routinely, i.e. hardwood floors and stairs, as its glossy sheen will make them slippery and dangerous.
A full can provides 125 sq ft of coverage, and a synthetic-bristle brush is the recommended applicator. However, I’ve found that spraying this poly generally achieves better results—but it’s up to you!
Usually, only three coats are needed, but if you live in an area that gets battered by the elements routinely, 4-5 are recommended.
It takes 2 hours for a coat to dry. The final coat should dry for 24 hours, unless the surface is a countertop, in which case 72 hours of drying time is necessary.
This poly, once fully cured, can be easily cleaned with warm, soapy water.
Finally, this product is backed by a warranty. So if you receive a defective product, let them know and they’ll replace it or refund you.
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When it comes to durability, few exterior polys can compete with TotalBoat Gleam Exterior Polyurethane. But its impressive strength isn’t the only thing it’s got going for it—it’s visually appealing, versatile, and relatively easy to apply too.
This is an oil-based exterior polyurethane, and it’s made with my favorite natural wood oil: tung oil.
Because it’s oily, it has a glossy sheen, but it’ll display more of a satin sheen if you add more resins before applying.
It’s also prone to yellowing over time, but this is only a problem if you apply it to light-colored woods. On the other hand, this yellowing can actually enhance darker woods.
Though it’s designed for outdoor use, particularly marine applications, it can be used indoors.
A full can will cover up to 250 sq ft, and it can be applied with a brush, roller, or sprayer.
The manufacturer recommends putting down 4-6 coats for interior and exterior surfaces, and I’ve found that six can withstand prolonged moisture quite well.
It takes about an hour for a coat of this poly to dry on outdoor wood surfaces, and it’s best to apply it when the temp is around 72° and there’s not much humidity.
Once dry, all you’ll need to clean it is warm, soapy water, but mineral spirits should be used to clean your applicator after you’re finished.
Read more : How to make cushion covers for outdoor furniture
And since this poly is self-leveling, the application process doesn’t take as long, and achieving a smooth, balanced finish is easier.
Finally, like other exterior polys, it has UV blockers and comes with a satisfaction guarantee.
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The exterior poly that’s going to be easiest on your wallet is Varathane Oil Based Spar Urethane, and it’s not just affordable but effective too.
This is another oil-based poly, and its clear satin finish highlights wood features in a subtle but distinct way.
And whereas other products on this list can be used as interior and exterior polyurethane, this one is solely for outdoor use, mainly because it contains more VOC.
Once completely cured, this oil-based polyurethane will seal the wood surface it’s been applied to, making it totally waterproof.
But it does yellow with age, so it’s best to keep it off light-colored exterior surfaces—I found this out the hard way.
Its maximum coverage is 190 sq feet, and you should apply at least three coats to ensure a durable, smooth surface.
I’ve found that a natural bristle brush is the best applicator, but I’m sure you can also use a roller.
It’ll be dry-to-touch in two hours and ready for another coat in eight. The final coat should get at least 72 hours of drying time before you resume using the surface as normal.
And like virtually all polys, it’s cleaned with soap and water and comes with a warranty or satisfaction guarantee.
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Many exterior polys claim to be “clear”, “non-yellowing”, etc., but Varathane Ultimate Water Based Spar Urethane is the only product I’ve come across that actually stays clear long after it’s fully cured.
Its ability to resist yellowing mainly comes from the UV blockers it’s made with. These blockers essentially reflect UV rays, and if they weren’t there the poly would eventually yellow as a result of prolonged sunlight exposure.
This is a water-based product with a glossy finish, so it can be used as exterior or interior polyurethane.
And like its sibling above, this poly will also keep a wood surface 100% waterproof, and that’s the main reason why I used it on my kitchen cabinets awhile back.
Exterior wood surfaces tend to need four coats, but more coats may be necessary if you live in an area that gets a lot of rain.
A can of this poly covers 87 sq ft, and it can be applied with a brush, roller, or sprayer.
After 30 minutes of drying it’ll be dry-to-touch, and after an hour you can add another coat. And after the final coat has been put down, wait at least 24 hours before you use it.
Finally, it’s less toxic, easy to clean, and comes with a pretty solid warranty.
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When an amber poly is what you’re after, consider ZAR High Performance Exterior Polyurethane, as it’s not just gorgeous but strong too, particularly when it comes to blocking out moisture and UV rays.
This water-based polyurethane has a satin sheen, and it can be used on wood and metal to great effect.
Read more : How do I care for outdoor wooden garden furniture?
It can be used as an indoor polyurethane too, since it’s less toxic, and it can be applied with a brush, roller, or sprayer.
To ensure a durable finish, the manufacturer recommends 3-4 coats; I’ve found that five are necessary in most cases.
You only need to wait an hour before adding a new coat. The topcoat should get at least 24 hours of drying time before you start using the surface as normal.
And, of course, this product is backed by a warranty, which I like just for the peace-of-mind factor.
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Strength is one of the most important factors to consider when browsing outdoor polyurethanes. Generally, oil-based polyurethane forms a more durable coating, and it lasts longer.
A sound polyurethane finish will protect a wood surface from scratches, impact damage, moisture, mold and mildew, pests, and UV rays.
But strength isn’t everything—exterior polyurethane should be attractive too. Or, at the very least, it shouldn’t diminish the visual appeal of the natural wood, stain, or paint underneath.
When thinking about polyurethane’s appearance, yellowing should be one of the first things you consider. Most polys yellow over time, and while this isn’t a problem for the majority of wood surfaces, it can be for light-colored woods.
Polys that are easy to use often yield the best results. Generally, exterior water-based polyurethane is easier to apply, as it’s thin, less odorous, and quick-drying. Also, there’s no mixing involved.
Oil-based polyurethane isn’t hard to use, per se. It does, however, take longer to apply, mainly because it’s much more viscous.
Want to know how to use exterior polyurethane more effectively? Check out the video down below!
Most exterior polyurethanes can waterproof outdoor wooden surfaces, but some only make them water-resistant.
When it comes to preventing moisture damage and all the things that come with it, namely mold and mildew, marine polyurethane does best.
An outdoor polyurethane must be able to withstand direct exposure to UV light, even if it doesn’t get a lot of this throughout the day.
It only takes a few hours of direct sunlight to yellow a once-clear polyurethane, but that’s only if the poly doesn’t have any UV blockers. These additives not only prevent yellowing but sunlight-related damage as well.
All polyurethane contains volatile organic compounds, but some have more than others. Water-based exterior polyurethane, for example, has less VOC, whereas oil-based poly has more.
To know how much VOC a poly has, simply look on the label; this information has to be included.
And if you can’t do this, do the “smell test”. That is, apply a little bit and see how odorous it is. Strong odor means more VOC.
The best polyurethane for sun exposure is one that includes UV blockers. These additives block UV rays to prevent surface discoloration and damage.
Depending on its composition, the surface it was applied to, how it was applied, and how it’s been maintained, an exterior polyurethane can last 10-20 years. Oil-based polys tend to last longer since they’re stronger than water-based versions.
Spar urethane is an oil-based product, whereas polyurethane can be oil-based or water-based. Spar urethane forms a richer, more durable finish, but it contains more VOC and takes longer to dry.
The best non-yellowing polyurethanes are water-based products that have UV blockers. Since they’re water-based, they don’t have the components that cause oil-based polyurethane to yellow, and the UV blockers prevent yellowing caused by the sun.
Minwax Helmsman Spar Urethane is the best of the best because it’s reliable, less toxic, easy to use, and great at bringing out the natural features in wooden surfaces. Moreover, it’s more affordable when compared to products of similar quality.
TotalBoat Gleam Exterior Polyurethane is the strongest exterior polyurethane, and as such it withstands prolonged exposure to the elements, expands and contracts with temperature fluctuations, and requires less maintenance.
Varathane Oil Based Spar Urethane is the most affordable polyurethane, yet it still delivers in all the ways that matter to me. It offers solid moisture and UV protection, it highlights a wood surface’s natural wood grain, and it’s easy to maintain.
Source: https://gardencourte.com
Categories: Outdoor
This post was last modified on 20/10/2023 12:49
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