How to Fix Epoxy Bubbles: Simple Tricks for a Smooth Finish

If you’ve ever worked with resin, you know the frustration of seeing tiny air bubbles rise to the surface and spoil an otherwise flawless finish. Whether you’re crafting glitter tumblers, jewelry, river tables, or art pieces, epoxy bubbles can be a persistent and annoying problem.

Learning how to fix epoxy bubbles is essential for any DIYer, resin artist, or small woodworking business that wants to achieve professional-quality results. At Artistry Epoxy, we’ve helped thousands of makers just like you overcome this common challenge with easy, expert-approved methods.

In this detailed guide, we’ll walk you through how to fix epoxy bubbles at every stage—from preventing them during mixing and pouring, to removing them before curing, and even repairing cured resin with trapped air pockets. With a few simple tricks and the right products, you’ll be on your way to creating bubble-free, glass-smooth masterpieces every time.

Why Do Bubbles Form in Epoxy?

Before diving into how to fix epoxy bubbles, it helps to understand why they appear in the first place. Bubbles in epoxy are often caused by common mixing and environmental issues.

1. Mixing Too Quickly

Stirring the resin and hardener too fast introduces air into the mixture, creating tiny bubbles that can rise to the surface later.

2. Pouring Too Thickly

Thicker pours trap heat and make it harder for bubbles to escape, especially in deep molds or tabletops.

3. Porous Surfaces

Materials like wood or canvas can release hidden air, which rises into the resin as it cures and forms bubbles.

4. Temperature Fluctuations

Cold or inconsistent temperatures increase resin thickness, preventing bubbles from escaping naturally.

5. High Humidity

Humidity can react with resin, sometimes causing a foamy or bubbly finish, especially during the curing stage.

Step-by-Step: How to Prevent Epoxy Bubbles from Forming

1. Warm Your Resin and Hardener Before Mixing

Cold epoxy is thicker and traps more air. Place your sealed bottles in a warm water bath (90–100°F) for 10–15 minutes before use. This lowers viscosity and helps bubbles rise to the surface during mixing.

Pro Tip: Never microwave your resin. Use warm water only.

2. Mix Slowly and Gently

Stirring too vigorously pulls air into your resin. Use a slow folding motion and stir for 3–5 minutes, scraping the sides and bottom of your mixing cup.

3. Let the Resin Sit After Mixing

Once you’ve mixed thoroughly, let the resin sit for 3–5 minutes to allow bubbles to rise naturally. You’ll notice a foamy layer on top—many of these bubbles will pop on their own.

4. Seal Porous Surfaces

If you’re working on wood or canvas, seal the surface first with a thin coat of resin or primer. Let it dry fully before pouring your final layer. This prevents air from escaping into the resin as it cures.

5. Pour in Layers, Not All at Once

Pouring thick layers traps more air and generates heat, causing bubbles. Stick to 1/8" to 1/4" layers for best results, especially for tumblers and art pieces.

How to Get Rid of Bubbles in Wet Epoxy

1. Use a Heat Gun or Torch

A heat source is your best friend for popping surface bubbles. Gently sweep a torch or heat gun 6–8 inches above your resin surface in a circular motion.

• Torch: Best for deeper pours or large surfaces
  

• Heat Gun: Great for tumblers or detailed art
  

Be cautious not to overheat one area. It can cause yellowing or dimples.

2. Toothpicks for Precision Popping

Got a stubborn bubble that won’t pop? Use a toothpick or pin to gently burst it—perfect for molds or corners.

3. Alcohol Mist for Silicone Molds

Spritzing 91% isopropyl alcohol from a fine mist bottle over resin in silicone molds can help pop surface bubbles without disturbing your design.

How to Fix Bubbles in Cured Epoxy

Sometimes, bubbles don’t show up until it’s too late, and the epoxy is already dry. But don’t worry. Here’s how to repair them:

1. Sand Down the Affected Area

Use 220–400 grit sandpaper to smooth out the area until the bubble is gone. Make sure to sand evenly around the edges.

2. Clean the Surface

Wipe away any sanding dust with isopropyl alcohol and a lint-free cloth. The surface must be clean before the next step.

3. Apply a Thin Flood Coat

Mix a small batch of resin and pour a thin flood coat over the repaired area. Use a heat gun to remove any new bubbles and let it cure.

Pro Tip: Always follow the manufacturer’s mixing ratio and cure times to avoid more issues.

Common Mistakes to Avoid

Even experienced resin artists can run into trouble. Here are a few common epoxy bubble mistakes and how to dodge them:

Over-mixing or under-mixing

Pouring too fast or too thick

Skipping a seal coat on porous materials

Working in a cold or humid environment

Not using a heat gun or torch

FAQs

Can you get bubbles out of epoxy after it dries?

Yes. Sand the area smooth with fine-grit sandpaper, clean the surface, and apply a new layer of epoxy to cover the defect.

How to fix epoxy bumps?

Epoxy bumps are usually caused by cured bubbles or dust. Sand them down flat and apply a final flood coat of resin.

How to fill air bubbles in resin?

Sand out the bubble, clean the surface, and apply a small amount of freshly mixed resin to fill the space. Let it cure properly.

What gets rid of bubbles in resin?

Use a torch or heat gun to pop surface bubbles while the resin is still wet. Letting resin rest before pouring and warming it can also help.

Wrap-Up: Get a Smooth, Glassy Finish Every Time

Epoxy bubbles might be common, but they’re 100% fixable. Whether you’re a beginner resin crafter or a seasoned DIYer, these simple steps can help you master the smooth, glass-like finish your projects deserve.

Warm it.

Mix gently.

Use heat.

Repair with confidence.

Ready to Create Flawless Resin Art?

Explore Artistry Epoxy’s line of professional-grade resins, vibrant pigments, premium glitters, and essential tools to take your craft to the next level.

Shop Artistry Epoxy Now and turn every project into a masterpiece.