Using Polyurethane on Cedar: A Comprehensive Guide

Are you wondering, “Can I use polyurethane on cedar?” Well, you’re not alone. Many woodworking enthusiasts and professionals alike often ponder this question. The answer is a resounding yes!

Polyurethane is a popular choice for finishing cedar, and for good reason. This article will delve into the specifics of why polyurethane is a preferred finish for cedar wood, and how it impacts the color and overall aesthetics of the timber.

Why Use Polyurethane on Cedar?

When it comes to finishing cedar, polyurethane is a top contender. But why is that? What makes polyurethane a good finish for cedar? Let’s break it down.

Protection Against Dirt, Dust, and Oil

First and foremost, polyurethane acts as a protective shield for your cedar wood. It keeps dirt, dust, and oil at bay, ensuring that your cedar remains clean and pristine. Imagine your cedar wood as a knight going into battle. The polyurethane finish is its armor, protecting it from the onslaught of everyday wear and tear.

Enhancing the Color and Aesthetics

Polyurethane doesn’t just protect your cedar—it enhances it. One of the most notable effects of polyurethane on cedar is its ability to darken the wood. This can bring out the rich, warm tones of the cedar, making it even more visually appealing. If you’re looking to add a touch of elegance and sophistication to your cedar, polyurethane might just be your best bet.

The Best Finish for Cedar?

So, what is the best finish to put on cedar? While there’s no one-size-fits-all answer to this question, polyurethane is certainly a strong contender. Its protective properties and aesthetic enhancement make it a popular choice among woodworkers. However, the “best” finish ultimately depends on your specific needs and preferences.

Types of Polyurethane for Cedar: Exploring Your Options

When it comes to finishing cedar, not all polyurethanes are created equal. Several types of polyurethane are particularly well-suited for cedar. Let’s take a closer look at these options and how they compare to other finishes like lacquer and linseed oil.

Spar Urethane: The Outdoor Champion

If your cedar project is destined for the great outdoors, spar urethane should be on your radar. This type of polyurethane is specifically designed to withstand the elements, making it an excellent choice for outdoor cedar furniture, decks, and other exterior woodwork. Spar urethane offers superior water resistance and UV protection, helping to prevent your cedar from warping, cracking, or fading in the sun.

Oil-Based Polyurethane: The Classic Choice

Oil-based polyurethane is a classic choice for finishing cedar. It offers a rich, warm finish that can bring out the natural beauty of the wood. Plus, oil-based polyurethane is known for its durability, making it a good choice for high-traffic areas or pieces that will see a lot of use.

Water-Based Polyurethane: The Eco-Friendly Option

If you’re looking for a more eco-friendly option, water-based polyurethane might be the way to go. While it doesn’t offer quite the same level of durability as its oil-based counterpart, water-based polyurethane is low in VOCs (volatile organic compounds), making it a safer choice for the environment and those with sensitivities to strong chemical odors.

Polyurethane vs. Lacquer vs. Linseed Oil

While polyurethane is a popular choice for finishing cedar, it’s not the only option out there. Lacquer and linseed oil are two other finishes you might consider.

Lacquer offers a high-gloss finish and dries quickly, but it doesn’t offer the same level of protection as polyurethane. It’s best suited for indoor projects or pieces that won’t see a lot of wear and tear.

Linseed oil, on the other hand, is a natural finish that penetrates deep into the wood, offering protection from the inside out. However, it doesn’t provide the same level of surface protection as polyurethane, and it can darken the wood significantly.

Applying and Maintaining Polyurethane on Cedar: A Step-by-Step Guide

So, you’ve decided to use polyurethane on your cedar project. Great choice! Now, let’s walk through the process of applying and maintaining your polyurethane finish.

Step 1: Preparation is Key

Before you start applying polyurethane, you’ll need to prepare your cedar. Begin by sanding the wood to create a smooth surface. Start with coarse-grit sandpaper and gradually work your way up to fine-grit paper. After sanding, wipe down the wood with a damp cloth to remove any dust.

Step 2: Applying the Polyurethane

When it comes to applying polyurethane, a good-quality brush is your best friend. Dip your brush into the polyurethane, then apply it to the cedar in long, even strokes. Always follow the grain of the wood to ensure a smooth finish.

You might be wondering, “How many coats of polyurethane on cedar?” The answer depends on the level of protection you want. For most projects, two to three coats should suffice. Allow each coat to dry thoroughly before applying the next one.

Step 3: Sand Between Coats

After each coat of polyurethane has dried, lightly sand the surface with a fine-grit sandpaper. This will help the next coat adhere better and result in a smoother finish. Remember to wipe away any dust with a damp cloth before applying the next coat.

Step 4: Final Coat and Drying

Apply your final coat of polyurethane, then let it dry completely. This can take anywhere from a few hours to a few days, depending on the type of polyurethane you’re using and the conditions in your workspace.

Maintaining Your Polyurethane Finish

Once your polyurethane finish is applied and dried, you’ll want to keep it looking its best. Here are a few tips for maintaining your finish:

  • Clean regularly: Wipe down your cedar with a soft, damp cloth to remove dust and dirt. Avoid using harsh cleaners, as they can damage the finish.
  • Protect from the elements: If your cedar project is outdoors, consider using a cover to protect it from rain, snow, and intense sun.
  • Touch up as needed: If you notice any scratches or wear in the finish, touch it up with a bit of polyurethane. Just sand the area lightly, then apply a new coat of polyurethane.

Common Mistakes When Applying and Maintaining Polyurethane on Cedar: What to Avoid

Applying polyurethane to cedar can be a straightforward process, but it’s not without its pitfalls. Here are some common mistakes people often make when applying and maintaining polyurethane on cedar, and how you can avoid them.

Mistake 1: Skipping the Sanding

One of the most common mistakes is skipping the sanding process. Sanding is crucial for preparing the cedar surface for polyurethane. It smooths out any rough spots and opens up the pores of the wood, allowing the polyurethane to adhere better. Always sand your cedar before applying polyurethane, and remember to sand lightly between coats as well.

Mistake 2: Applying Too Thick a Coat

Another common error is applying the polyurethane too thickly. While it might be tempting to slather on a thick coat in the hopes of finishing faster, this can lead to a sticky, uneven finish. Instead, apply thin, even coats and allow each one to dry thoroughly before applying the next.

Mistake 3: Not Sealing the Cedar

Cedar is a porous wood, which means it can absorb moisture from the air. This can lead to warping or cracking over time. To prevent this, it’s important to seal your cedar before applying the polyurethane. A good-quality wood sealer will fill in the pores and provide a solid base for the polyurethane.

Mistake 4: Neglecting Maintenance

Once the polyurethane is applied, some people make the mistake of thinking their job is done. However, maintaining your polyurethane finish is just as important as applying it. Regular cleaning, protection from the elements, and occasional touch-ups will keep your cedar looking its best.

Mistake 5: Ignoring the Weather

If you’re working on an outdoor project, it’s important to pay attention to the weather. Applying polyurethane in extreme temperatures or high humidity can affect the drying time and the quality of the finish. Aim for a day with moderate temperatures and low humidity for the best results.

Alternatives to Polyurethane for Cedar: Exploring Other Options

While polyurethane is a popular choice for finishing cedar, it’s not the only option out there. Depending on your project and personal preferences, you might consider other finishes such as lacquer, shellac, or varnish.

Lacquer: The High-Gloss Option

Lacquer is a finish that’s known for its high-gloss sheen and quick drying time. It’s easy to apply and can be polished to a high shine, making it a popular choice for furniture and other indoor cedar projects. However, it doesn’t offer the same level of protection as polyurethane, so it’s best used on pieces that won’t see a lot of wear and tear.

Shellac: The Natural Choice

Shellac is a natural finish derived from the lac bug’s secretions. It’s non-toxic, easy to apply, and gives the wood a warm, rich color. However, shellac isn’t as durable as polyurethane and can be damaged by heat and alcohol, so it’s best used on decorative pieces.

Varnish: The Durable Alternative

Varnish is a durable finish that’s resistant to heat, chemicals, and water. It’s more difficult to apply than polyurethane, but it offers excellent protection, making it a good choice for outdoor cedar projects.


Using polyurethane on cedar offers numerous benefits. It provides a protective shield, enhances the color and aesthetics of the wood, and is relatively easy to apply and maintain. While there are other finishes available, such as lacquer, shellac, and varnish, polyurethane remains a top choice for many due to its balance of protection, beauty, and ease of use.

One final option to consider is cedar stain. This finish penetrates the wood and provides color, but doesn’t offer the same level of surface protection as polyurethane. It’s a good choice if you’re looking to change the color of your cedar, but for overall protection and enhancement, polyurethane is hard to beat.