Can You Roll On Polyurethane? Easy Tips to Polyurethane Application

Polyurethane seals surfaces with scratches and other blemishes. It also preserves the surface from debris and moisture and keeps the items in good shape for a longer duration. In addition, the formula offers sheer beauty. But how to you apply this formula to your wooden structures? Can you roll on polyurethane?

Yes. It is okay to roll on polyurethane. Moreover, rolling eliminates brush lines and strokes and prevents over-application. Therefore, you can be sure to deliver a smooth and flawless finish. However, please avoid over-working the surface with a roller. The move would break the chemical reaction in an oil-based polyurethane and cause streaks in a water-based formula.

In this article, I have discussed a lot regarding the polyurethane, its application and more. Keep reading for more on this subject.

What Kind of Roller Do You Use With Polyurethane?

A foam roller wrapped in a cloth or plastic would be an excellent applicator for polyurethane. In addition, it would be best to get an accessory that prevents dust and lint from mixing with the surface. Thus, short fiber and lambswool paint rollers will also give a perfect outcome.

Additionally, regardless of the roller you pick, please work gently on the surface. This way, you avoid leaving streaks on the surface.

What Is the Best Applicator for Polyurethane?

The best polyurethane applicator is fine bristled brushes, either synthetic or natural. You can also get a foam brush and deliver a desirable coat. In addition, other tools such as rollers and pads attached to poles are perfect for small areas, whereas T-bars are suitable for large floors.

Also, it is advisable to avoid cheap bristle paintbrushes as they leave noticeable brush strokes. But you can still get disposable and inexpensive foam brushes for flat surfaces. Thus, please assess the nature of the surface and get the best applicator.

You can get the best applicator but still, get a failed product because of using the wrong technique. Thus, ensure that you brush on the polyurethane formula parallel to the grain. Also, it will help to use a thin but sufficient coat. Then, complete the area with straight, long strokes to eliminate bubbles.

Is It Better to Brush or Roll Polyurethane?

You can easily apply polyurethane with a roller or paintbrush and expect it to dry quickly. However, most woodworkers prefer rollers because they eliminate brush strokes and lines. The accessories also prevent over applying the formula and thus, facilitate an even and uniform finish.

In addition, dampen the roller’s surface by placing it in a pan with mineral spirits. Then, shake off any excess to ensure that it does not drip. The mineral spirits help in applying polyurethane. Also, it will be best to roll on the material quickly until the roller can no longer contain any polyurethane.

How Do I get a Smooth Finish With Polyurethane?

The first step is always to prepare the object. A glass smooth finish begins with a clean, even, and level surface. Hence, get a detergent and degreasing agent and get to work! Also, you can assess the surface for cracks, holes, and scratches. Then, fill them with a wood grain filler.

Apply the stain and polyurethane and allow it to dry completely. You can consider placing the object in an area with less foot traffic and dust. On top of that, ensure that you sand the workpiece to remove any bumps and imperfections.

In addition, prepare the formula by reducing it to about 10% with mineral spirits. The exercise makes polyurethane flow on the surface more smoothly and reduces brush streaks and lines. However, you do not need thinning if you have a water-based product.

On top of that, make long brushstrokes and overlap the edges to get full coverage. Then, wipe off any excess stain to facilitate a uniform finish. Also, please consider thin coats and do not brush excessively. Or else, you’ll have areas with little polyurethane.

Woodworker using Rigid, the Best Cordless Random Orbital SanderAllow every coat to dry before adding subsequent layers. You can sand between the coats with 320-grit sandpaper. It fosters a tight bond between the layers and, eventually, a durable finish. In addition, do not panic if the first coat does not look perfect. Ensure that you sand well and the finish will get in shape as you add other layers.

Also, sand the third coat with 320-grit, then a 400 one, and lastly 600-grit sandpaper. Ensure that you do it in alternating directions with each abrasive. This way, you can check whether you’ve eliminated scratches from the previous grit.

Next, wipe off the surface with a cloth dipped in mineral spirits. You can also spray the coat using an aerosol polyurethane and let it dry overnight. The final coat gives you a smooth feel and a lovely appearance. 

So, hold the spray nozzle 12 to 16 inches from the surface and sweep the can across the object. Then, eliminate dust nibs with 1,500 grit sandpaper. Also, please stick to only one coat for optimal results.

Lastly, use a polishing pad or cotton rag to buff the surface to give a high shine. You can also have some automotive wax with fine abrasive to polish the finish further. In addition, it would be best to work in the grain direction to hide fine scratches.

NB: Select the most suitable wood filler as they come in different colors. Ensure that you get one that blends perfectly with the workpiece to deliver an even appearance. Also, you can choose one that contrasts the surface’s hue for a more pronounced grain.

On top of that, you can shine a light at a low angle across the finish to reveal bubbles, brush marks, and other blemishes as you work.

What Happens If You Don’t Sand Between Coats of Polyurethane?

The texture of the polyurethane feels rougher if you do not sand between polyurethane coats. But the imperfection is not notable with a naked eye. Also, the layers will bond and adhere to each other whether you sand or not.

On top of that, sanding helps to deliver a gloss on the pores, which is not a mandatory result. Thus, you will not compromise your work if you refuse to sand. Besides that, you have to wait for about 24 to 48 hours to allow the finish to dry and harden. Thus, sanding may be a time-consuming venture.

How Many Coats of Polyurethane Is Too Many?

It would be best to have a minimum of two coats as it works for most surfaces. However, you can have at least three coats for floors and other areas experiencing occasional moisture exposure.

In addition, each coat enhances the topcoat’s smoothness. Hence, the more, the better. But there is a caveat. More than four coats may not be a good idea as you will have more drying time. Also, you’ll need to buff the surface every time you add a coat. Therefore, you may end up wiping off half the previous layer.

So, consider three to four coats for your project. The make the lumber semi impervious as the polyurethane coat will be thicker and more cohesive. On top of that, the protection will be superior and will last longer. Thus, you won’t have to sand or refinish the surface for a longer duration.

Do I Need to Sand Between Coats of Polyurethane?

The first coat should appear smooth and thus, needs the most sanding. Also, the subsequent polyurethane coats need something to adhere to, and sanding delivers just that! However, you do not need to sand between polyurethane coats. But it will enhance your finish if you do it. 

Besides that, sanding smooths any brush marks or dust nibs on the surface. Therefore, the nest coat will look much better. But you can skip the sanding process altogether if you apply thin and uniform coats. Also, you are good to go, provided you allow each coat to dry properly before adding another one.

Even so, you can consider sanding polyurethane on floors for maximum smoothness. However, please ensure that the surface dries for about 12 hours before you proceed. Also, sand lightly to avoid exerting undue pressure on the finish.

Can I Use a Foam Brush to Apply Polyurethane?

 Yes, it is okay to use foam brushes to apply polyurethane. They deliver perfect results, and you can throw them away after use since they are cheap. Thus, the brushes eliminate the chore of cleaning brushes after painting.

However, these brushes are only suitable for smaller projects, like decorating a birdhouse. Foam brushes will frustrate you on large surfaces as they cannot spread the polyurethane like natural or synthetic ones.

How Many Coats of Water Based Polyurethane Should I Use?

Three coats of water based polyurethane coats are the best to use. More that would require more drying time and would deliver a thick and gloppy layer. Thus, you may get a peeled surface after some time.

On top of that, please avoid applying more than two coats in one day. Ensure that you give each layer enough time to cure and harden. Also, use a maroon abrasive pad or 120 to 150-grit sandpaper if you must sand the coats.

In addition, vacuum the object and wipe the surface with a clean and lightly dampened lint-free rag. This way, you can eliminate all the dirt and dust before having subsequent coats.

It is advisable to avoid applying too much polyurethane in one layer. The wood grain may rise to the surface and compromise your work. Also, you might observe a white film over the finish after sanding. This scenario should not worry you as it disappears as you lay the next coat.

How Do You Apply Water Based Polyurethane Without Bubbles?

One of the strategies to eliminate bubbles when applying polyurethane is not shaking the can. Instead, stir the mixture as it improves the formula’s flow. Thus, the coat levels properly on the surface.

Also, it would help to clean the surface as dust, lint, and dirt may hinder proper adherence. Therefore, you will notice bubbles after the job. You can set aside a few minutes and clean the surface thoroughly.

The other strategy involves wetting the brush during application. The air pockets in the brush will leave tiny bubbles on the finish. Therefore, ensure the bristles are wet and stick together.

Finally, you can water down the polyurethane to keep bubbles away. Also, please adhere to the appropriate ratios to avoid diluting the formula excessively. This way, you will thin the formula without compromising its durability and quality.

Why Does My Polyurethane Have Bubbles?

Polyurethane is different from spray paint. Hence, shaking it will cause bubbles to form on top of the surface. Instead, stir the formula to mix it properly and facilitate a smooth flow. In addition, ensure that you eliminate air in the brush by wetting it before application. Soak the brush in water, and then allow all the water to drip before using it.

Additionally, please select the most suitable solution for wetting the brush. For example, use a solvent-based liquid for oil-based polyurethane and water for a water-based formula. Also, remember to avoid using solvent-based solutions with water. The exercise will present more issues to deal with and not just bubbles.

Besides that, a contaminated surface also leads to bubbles on the surface. Therefore, you’d have to get mineral spirits to eliminate accumulated dirt and lint. Also, give the surface enough time to dry before applying the formula.

Does Polyurethane Make Wood Waterproof?

No. A polyurethane formula does not make the wood waterproof. Rather, it makes the surface water-resistant. The solution also prevents water absorption and thus, increases the wood’s protection. But, please note that polyurethane does not block water fully from the lumber. Therefore, it would be best to keep your surface away from excess moisture. 

In addition, the lumber contracts and expands over time and creates more gaps for moisture. This scenario results in wearing off, warping, and swelling. Hence, the formula wears down and becomes more vulnerable to natural abrasions.

Fortunately, the formula protects lumber from discoloration and scratches. It also makes the wood look finished. So, having it on your surface is profitable after all.

Will Polyurethane Darken Stain?

Polyurethane darkens some stains and woods slightly. Oil-based polyurethane formulas also have an amber hue that can change the color of wood significantly. In addition, remember that paint cures darker than its original color when it’s wet. But stains usually dry to give a lighter color. 

Also, the formula may brighten the varnish a little, which differs from what happens with stains. The stained finish has a lighter surface that reflects more light. Thus, it gives the impression of being darker.

So, it would help to ensure that the stain is dry before making a decision. This way, you can determine how the polyurethane will affect the finish.

How Do You Get Brush Marks Out of Polyurethane?

Do not panic once you see brush marks on your polyurethane finish. The removal strategy is pretty simple. First, sand the final coat with a 220-grit foam sanding pad. Then, add another layer of the formula. Also, add the solution more liberally than you did before. Only this time, avoid heavy back-brushing.

Next, dip the brush in polyurethane and let it drain the excess formula. You can also wet sand the surface with 600 grit sandpaper. Besides that, mix some dishwasher detergent and water for stubborn and greasy stains. This solution will help you deliver a perfectly clean surface.

You can lightly coat the finish to disguise the area if you do not want to sand it. However, you can still sand the surface if that’s what you want. But ensure that you brush the sanded area with a soft cloth. This way, you remove all grit and dirt traces front the process.

Lastly, thinning the polyurethane solution and stirring it eliminates the possibility of brush marks. In addition, it delivers a smoother finished surface than a thick formula.

How Do You Fix Bad Polyurethane?

Polyurethane has multiple benefits that make it outshine lacquer and alkyd finish. It forms a hard plastic on the surface and thus offers unmatched protection. However, the formula tends to produce bubbles that can lead to a failed product. It can also crack, run, or get checks with poor maintenance.

Even so, there is always a way out. You can troubleshoot bad polyurethane and end up with a successful job. Check out the following tricks.

  • Sand down dried drips with 220-grit sandpaper or scrape them off with a razor blade. Also, please avoid working on tacky drips as they may worsen the situation.
  • Identify hardened bubbles in the finish and flatten them with 220 grit sandpaper. Then, take appropriate measures to prevent them from forming again and recoat the finish.
  • Assess the surface for any bubbles during painting or spraying and pop them. Fortunately, you can prevent them from occurring by applying polyurethane in moderate temperatures or brushing more gently and slowly.
  • Use a pull scraper to remove the finish from a horizontal surface. Then, wash the surface with a recommended solvent while it is still wet. Also, it would be best to use mineral spirits for solvent-based formulas and water for water-based ones.
  • Add a leveling agent to the polyurethane solution to minimize bubbling during a recoat.
  • Remove the finish with a sanding accessory if it turns white or cloudy after curing. This scenario happens when moisture in the wood comes into contact with a solvent-based formula. Thus, it would be best to use the solution when the wood is dry.

Frequently Asked Questions

Some of the most asked questions regarding the subject includes:

  • How Do You Fix Polyurethane That Won’t Dry?

Your polyurethane coat is not dry yet because the layer is too thick. Also, you can expect to have a longer dry time if the weather is humid or cold. Hence, you can solve the problem by applying thinner layers on the surface with a natural bristle brush. Be stingy with the formula during application.

In addition, you can turn up dry heat or move the polyurethane-coated work to a warmer area. However, moving the surface may not make a huge difference. Thus, apply heat with a blow drier or heat lamp and turn on the humidifier.

  • Why Does My Polyurethane Turn White?

White spots form on a polyurethane finish because of moisture buildup. They also appear if you do not stir the formula properly before applying it. Hence, your surface is safe if you seal the wood and follow the manufacturer’s instructions on the product usage.

However, there is still hope if you identify white spots on the finish—sand down the high spots with suitable sandpaper. Also, you can dry out the moisture using a heat lamp or blow-drier.

  • Should I Use Sealer Before Polyurethane?

The decision to have a sealer before polyurethane depends on which polyurethane product you are using. Some formulas do not require a sealer and yet provide maximum protection to the surface.

On the other hand, some polyurethane solutions need a sealer to deliver a successful paint job. However, ensure that the sealing product is compatible with the polyurethane. You can also consider a penetrating resin product. It finishes the lumber, but you get a smoother finish after adding a polyurethane coat.

Also, it will help to read the formula’s user’s guide as it will direct you on the best way to apply it.


Polyurethane is a popular formula in our day. It protects the surface from water damage and scratches. Thus, giving the wood longevity. Unfortunately, most of us are not aware of how best to apply it or maintain it. So, this article has sought to answer the query:

Can You Roll On Polyurethane?

Of course, yes! You can apply polyurethane using rolling accessories. In addition, the process is pretty simple and quick and allows you to get full coverage. However, ensure that you pick the correct size for your contact surface to deliver an excellent paint job.

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Tyron Otieno

Tyron is an avid woodworker and writer. He founded this website to help other woodworkers, whether hobbyists or professionals by sharing his knowledge and experiencie after a decade of woodworking.

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