The Best Wood Sealers to Keep Your Outdoor Furniture Looking Beautiful

Confused about how to best protect your outdoor wood furniture? I’m sharing the most popular outdoor wood sealers, the pros and cons of each, and my picks for the best and easiest to maintain.

I love using wood furniture outdoors on our porches and patio. Whether it’s furniture I’ve bought or something I’ve made myself, wood furniture looks beautiful outdoors.

Wood is actually a great material for outdoor furniture. It’s sturdy, natural, works with all kinds of different design styles, and is often pretty affordable.

But finishing your outdoor wood furniture so that it can hold up to the elements is absolutely crucial. If you don’t seal wood properly, it will start to fade, mildew, and may eventually even rot.

And no, you can’t just use the same polyurethanes and top coats you’d use on indoor furniture. Instead, you need something that can withstand temperature fluctuations, moisture, and direct sunlight.

This is what I look for in a great outdoor wood sealer:

• Can handle fluctuations in temperature and humidity.
• Protects wood from UV rays.
• Is water resistant and help prevent mildew.
• Is easy to apply and easy to maintain year after year.

Over the years I’ve used lots of wood furniture outdoors. As I write this, I’m sitting on my back porch and just within my current view I can see 5 pieces of wood furniture I built myself, 2 pieces of indoor wood furniture I repurposed to use outdoors, and one set of wooden chairs I bought unfinished and sealed myself. And half of that furniture has been outdoors for 4-5 years now so I’ve gotten to see firsthand how it holds up over time.

I know it can be confusing knowing how best to protect outdoor wood furniture, so today I’m sharing a simple breakdown of the most popular exterior wood sealers along with my personal top recommendations.

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What kind of wood can go outdoors?

Before we get into the best sealers, I want to take a quick minute to talk about what types of wood you can use outdoors.

There are certain woods like cedar, redwood, acacia, and teak that naturally pretty resistant to moisture and rot. These woods are often used in furniture that is sold to be used outdoors. You don’t always have to seal these woods since they are naturally rot resistant, but even these woods will become damaged by sun and rain over time. Sealing them will definitely help them last a lot longer.

If you have cedar furniture you are planning to seal, I have another post focused completely on how to best seal cedar wood furniture.

You can also use all kinds of other woods outdoors. I’ve made quite a few pieces of outdoor furniture from inexpensive pine wood. Nobody would ever claim pine is a wood that holds up well outdoors, but when it is sealed properly, it can hold up for years. I have pine furniture outdoors that I built five years ago and it still looks great.

I have also repurposed several pieces of thrifted indoor wood furniture to be used outdoors. The key is to make sure you seal all exposed surfaces of the wood before bringing it outdoors. Just remember that even with proper preparation, your furniture probably won’t last quite as long outdoors so don’t bring out any prized heirlooms.

Want to know more? Check out this post for everything you need to know about using indoor furniture outdoors.

So what kind of wood can go outdoors? My answer would be almost any kind of wood! As long as you seal your wood furniture well, most wood will do just fine outdoors.

Exterior Wood Sealers

If you love the natural wood look, it’s important to note than even clear sealers will slightly alter the color of your wood. To get an idea of how your wood will look once sealed, you can wet it with water. In addition, most oil-based products will also yellow your wood finish.

Spar Urethane

Spar urethane is a clear outdoor sealer that forms a barrier to protect wood from the elements. It protects wood from UV rays, rain, moisture, and temperature fluctuations.

Spar urethane can be applied to natural wood or used over a wood stain in the color of your choice. (And no, you don’t have to use an exterior stain. Any stain will work.)

Spar urethane is available in both oil-based and water-based versions. Oil-based spar urethane is more durable, but can yellow your wood over time. Water-based spar urethane doesn’t yellow, but it also isn’t quite as durable. I typically use the oil-based version for the added durability.

Though it is available in satin, semi-gloss, and gloss sheens, I highly recommend using satin on almost any wood project. The less shiny finish looks much more natural.

You’ll need to apply several coats of spar urethane to get adequate protection. I like to apply multiple coats thinned with Mineral Spirits. I first found this method at The Wood Whisperer and it makes it so much easier to get a clean, streak-free finish!

This is my go-to outdoor finish and I have used it to seal the wood table, bench, and outdoor chair on my back porch.

This is the spar urethane I typically use: Minwax Spar Urethane (oil-based) in satin finish.

Spar Varnish

Spar varnish is sometimes also called marine varnish or boat varnish. It is used to seal boat masts and booms, so it can clearly hold up to moisture and even saltwater.

Even though the names are similar, spar varnish is not the same thing as spar urethane. They are used for similar purposes, but are made using different resins.

Like spar urethane, spar varnish creates a film finish over the wood. It helps protect against UV rays, moisture, and water. Spar varnish is often recommended as a great finish for outdoor furniture because of it’s ability to withstand tough weather conditions, but it does have some downsides.

Best practice is to apply 5 -7 coats of spar varnish for a good finish which is time consuming. It also needs to be reapplied often – as much as every six months to a year. And when the finish fails over time, it tends to crack and peel and look terrible until it is sanded down and reapplied.

While you may be able to find spar varnish at your local home improvement store, most woodworkers don’t recommend those. Instead, Epifanes marine varnish is the most highly recommended, but it is pretty expensive.

For all these reasons, I haven’t personally used spar varnish on outdoor furniture, but I wanted to include it since it is often recommended.

Exterior stain and sealer combo

If you want to add more color to your wood furniture, an exterior stain + sealer is a great option. Typically people use this on decks but it will also work on outdoor furniture.

Exterior stains protect wood against UV rays, moisture, and mildew. They come in a huge range of colors including all the traditional wood tones as well as lots of nontraditional colors like blues and greens.

One of the big advantages of an exterior stain is you typically only need to apply one coat which can save a lot of time.

You can choose from exterior stains in clear, semi-transparent, semi-solid, and solid. Clear stains are a great choice when you want to preserve the original color of your wood, but they do have the lowest amount of UV protection. Solid stains have the most UV protection, with semi-transparent and semi-solid falling somewhere in between.

Semi-transparent stains will slightly change the color of your wood while still letting the wood grain and color variation show through. Semi-solid stains let a bit less wood grain show but offer more protection. And solid stains completely cover the wood variation similar to a paint. Unlike an exterior paint though, a solid stain penetrates into the wood rather than simply sitting on top.

Tung Oil or Boiled Linseed Oil

Did you know that you can also use a good oil to protect wood? Oils like tung oil and boiled linseed oil don’t technically ‘seal’ wood the way other sealers do. Instead of forming a film coating over the wood, they protect by penetrating deep into the wood.

These oils can protect wood from fading caused by UV rays, temperature fluctuations, moisture, and mildew. I love that they are extremely easy to apply. They do need to be reapplied every year or so which is more frequently than something like spar urethane. But when it’s time to reapply, you don’t have sand or scrape off the old finish, you can simply rub on a new coat.

I recently used General Finishes Outdoor Oil to seal my cedar Adirondack chairs and I’m a big fan. This outdoor wood oil has added UV stabilizers for increased protection from direct sunlight.

I would not recommend using an oil on furniture made from less outdoor-friendly woods like pine or poplar. It works really well with woods that already have some natural water resistance, but doesn’t really have the needed durability for other woods.

Exterior paint

One of the best ways to protect wood furniture outdoors is to paint it. Exterior paints are specially formulated to hold up well outdoors. They resist fading from UV rays, protect wood from humidity and rain, and resist mildew.

Of course paints aren’t a great option if you want a natural wood look, but if you’re open to a solid color, paint’s a great option.

Paint is super easy to apply, comes in an almost endless array of colors, and holds up well over time. And since exterior paints already have protective properties, you don’t need to apply a separate top coat over your paint. (However, I do recommend using a separate primer first when painting raw wood furniture.)

Need more details? I have lots more info on the best steps to take when painting outdoor furniture.

I’ve painted many pieces of outdoor wood furniture and they’ve all held up well. Of course paint will also eventually start to chip and peel, but in my experience it typically lasts a lot longer than clear finishes do.

If you’re thinking about painting outdoor furniture, I recommend you check out the results of my test to see what outdoor furniture paint actually works the best.

How long do wood sealers last?

I really wish that you could seal your wood furniture, place it on your patio, and be down with it. Sadly, that isn’t how it works in real life.

The good news is if you seal your wood furniture properly, it can last outdoors for many, many years. The bad news is you will still have to do ongoing maintenance during that time.

No matter what type of finish you put on your outdoor furniture and how perfectly you apply it, it will eventually fail. What does that mean? The finish may start to peel and crack. Your wood may start to look dry and discolored. If your wood furniture starts to look generally bad and a simple cleaning doesn’t revive it, it’s probably an issue with the sealer.

There are a lot of factors involved in how long your sealer will last. If your furniture is in direct sunlight in a very hot, sunny climate or at a high elevation, the finish will start to degrade more quickly. If it is on a covered porch and more protected from the elements, it will probably last a bit longer.

Of course it isn’t an exact science, but sealers that create a film finish over your furniture (like spar urethane) tend to last a bit longer. Typically 2-5 years. The downside is that these finishes look worse when they do fail – they’re the ones that crack and peel. And they are a bigger pain to fix since you’ll need to remove the old finish before reapplying.

Penetrating oil finishes like tung oil and boiled linseed oil typically need to be reapplied more often – every 6 months to 1 year. But reapplying is much simpler; you just add another coat without any laborious prep work.

And lest this seem discouraging, keep in mind that while no wood sealer is perfect, they are all much, much better than leaving your outdoor furniture unprotected.

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