Will Bubbles In Polyurethane Go Away


Bubbles are an unsightly part of the polyurethane process. They can form when the liquid is injected into the mold, and they often cause problems with the final product. Many people ask whether the bubbles will go away after the polyurethane has been cured. In this blog post, we will answer that question and offer some tips on how to get rid of bubbles in your polyurethane products.

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Will Bubbles In Polyurethane Go Away?

No, bubbles in your dried polyurethane won’t go away on their own, however, there is a way to fix this issue. 

To get rid of bubbles in your polyurethane finish, start by sanding the area using 120-grit sandpaper until the surface is smooth. Then, wipe away any dust with a tack cloth and apply a new coat using a brush or roller specifically designed for use with this product. Be sure to follow the manufacturer’s instructions carefully to avoid creating new bubbles in the finish.

If you’re still seeing bubbles after taking these steps, you may need to strip the old finish and start again from scratch. This is a more time-consuming process, but it will ensure that your polyurethane finish is smooth and bubble-free.

What Are Bubbles And Why Do They Form In Polyurethane Products?

Bubbles are tiny pockets of air that become trapped in a mixed polyurethane resin system. When the bubbles pop, they leave behind a small hole. 

Bubbles can form for several reasons:

  • The mixture is too thick and the bubbles have nowhere to go.
  • The mixture is not stirred properly and the air pockets become trapped.
  • The mixture is applied too thickly and the bubbles have nowhere to escape.
  • The temperature is too cold and the bubbles contract.
  • The surface is not smooth and the bubbles are unable to rise to the surface.

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How Can You Get Rid Of Bubbles In Your Polyurethane Products?

We’re all familiar with the telltale signs of a bad polyurethane job: runs, drips, and, most noticeably, bubbles. 

Bubbles in your polyurethane finish are caused by shaking the can, using the wrong brush, and improper brush preparation. When you apply a new coat, these bubbles become trapped in the wet finish and become permanent flaws when the polyurethane dries.

To get rid of bubbles in your polyurethane finish, start by sanding the area using 120-grit sandpaper until the surface is smooth. Then, wipe away any dust with a tack cloth and apply a new coat using a brush or roller specifically designed for use with this product. Be sure to follow the manufacturer’s instructions carefully to avoid creating new bubbles in the finish.

If you’re still seeing bubbles after taking these steps, you may need to strip the old finish and start again from scratch. This is a more time-consuming process, but it will ensure that your polyurethane finish is smooth and bubble-free.

With a little patience and attention to detail, you can achieve a beautiful, smooth finish on your polyurethane products. Just be sure to avoid shaking the can, using the wrong brush, and failing to prepare your surface properly. By following these simple tips, you’ll surely enjoy a flawless finish for years to come.

What Are Some Tips For Avoiding Bubbles In Your Polyurethane Products?

So what can you do to prevent or eliminate bubbles in your polyurethane finishes? 

Here are a few tips:

  • Use a good-quality polyurethane that is designed for the job at hand.
  • Make sure the surface you’re applying the polyurethane to is clean, dry, and free of dust and debris.
  • Apply thin, even coats of polyurethane, using a brush or roller designed for use with this type of finish.
  • If bubbles do appear, pop them with a pin and then smooth them over with a brush.

By following these simple tips, you can avoid or eliminate bubbles in your polyurethane finishes and achieve the beautiful, smooth results you’re looking for.

Is It Normal For Polyurethane To Bubble?

The quick answer is yes, bubbles in polyurethane are normal. Bubbles occur when the polyurethane mixture starts to set and the solvents escape from the mixture too quickly. The bubbles usually pop on their own and don’t cause any long-term damage to the finish.

You can add a paint thinner to your polyurethane to slow the drying process down so the bubbles are more likely to pop prior to fully drying.

How Do You Stop Bubbles In Water-Based Polyurethane?

To get rid of the bubbles in your water-based polyurethane, you can add a flow additive to your finish. Flow additive is a liquid that you add to the polyurethane that helps it level out and eliminates bubbles. You can find flow additives at most hardware stores or online.

To use a flow additive, simply mix it into your polyurethane according to the manufacturer’s instructions. Then, apply the polyurethane to your project as normal. The flow additive will help the polyurethane level out and eliminate any bubbles.

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Kevin Nelson

I will always have a special place in my heart for woodworking. I have such fond memories working on projects with my parents on the weekends in the garage growing up. We built tables, shelves, a backyard shed, 10' base for a water slide into the pool, 2 story fort playhouse with a fire pole, and so much more. This woodworking blog allows me to write helpful articles so others can enjoy woodworking as much as we have.

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