What Causes Resin to Bubble?

What Causes Resin to Bubble?

Mar 19, 2024

Resin is a versatile material commonly used in various crafts and art projects. It is a thick substance that can be shaped into different forms, making it popular for creating jewellery, decorative pieces, and even furniture. However, when working with resin, artists and crafters often encounter bubbles in their projects. Joining a resin art workshop offers a hands-on opportunity to learn about the reasons behind resin bubbles first-hand and acquire effective prevention techniques.

Preventing bubbles in resin projects is essential for achieving a smooth and professional finish. Bubbles can take away the overall appearance of the final piece, impacting its quality. By understanding the causes of bubble formation and taking preventive measures to reduce them, you can create flawless results in their resin artwork.

Common Factors that Cause Resin to Bubble

When working with resin, it's important to understand the common factors that can cause bubbles to form. By being aware of these factors and taking preventive measures, you can achieve a smooth and bubble-free finish in your resin projects.

Mixing Too Quickly

When resin and hardener are mixed too quickly, it can introduce air bubbles into the mixture. This is especially true if you use a high-speed mixer or stir vigorously. To avoid this, it's best to mix slowly and gently, ensuring that the resin and hardener are thoroughly combined without incorporating excess air.

Cold Resin

Resin that is too cold can also lead to bubble formation. Cold temperatures can cause the resin to thicken, making it harder for bubbles to escape during the curing process. To prevent this, make sure to store your resin in a warm environment before using it and ensure that your workspace is at an optimal temperature.

Pouring Resin Too Thick

Pouring a thick layer of resin at once can trap air within the mixture, resulting in bubbles. It's important to pour thin layers, allowing each layer to cure before adding another one. This gives trapped air enough time to rise to the surface and escape before the next layer is poured.

Trapped Air

Sometimes, air can get trapped between the resin and the surface it's applied on, such as a canvas or mould. This can happen when pouring resin onto a textured surface or when using a mould with intricate details. To minimise trapped air, you can use a heat gun or blow torch to gently heat the surface of the resin, which helps air bubbles rise and pop.

By being mindful of these common causes and taking appropriate measures, such as mixing slowly, maintaining optimal temperatures, pouring thin layers, addressing trapped air, and following best technique, you can effectively reduce the risk of bubbles in your resin projects.

Techniques to Effectively Prevent Bubbles in Resin

When working with resin, it's crucial to employ various techniques to prevent bubbles and achieve a flawless finish. Here are some effective methods to help you minimise the risk of bubbles in your resin artwork:

Using a Torch or Heat Gun

After pouring the resin into your mould, you can use a blow torch or hot gun to carefully apply heat over the surface. The heat helps to burst any tiny bubbles that may be present, resulting in a smoother appearance. Hold the flame of the torch or heat gun several inches above the resin surface and move it gently and consistently across the entire area.

Avoiding Whipping the Resin

Vigorously stirring or whipping the resin can introduce air into the mixture, leading to an increased likelihood of bubbles forming. Stir the resin slowly and methodically, ensuring that you reach all areas of the mixing container without creating unnecessary turbulence.

Pouring Slowly

Pouring the resin slowly into the mould minimises splashing and disturbance, which can contribute to bubble formation. Take your time when pouring the resin, allowing it to flow smoothly and evenly without creating excessive movement.

Warming the Resin

In some cases, warming the resin before use can help reduce its viscosity and make it easier for air bubbles to rise and escape. Place the closed containers of resin in warm water for a few minutes before mixing and pouring.

Pre-sealing Porous Materials

Porous materials such as wood or paper can release air into the resin, causing bubbles to form. Apply a sealant or primer to porous surfaces before incorporating them into your resin artwork to prevent air from being released during curing.

By incorporating these techniques into your resin casting process, you can significantly reduce the occurrence of bubbles and enhance the overall quality of your finished artwork.

Tips for Minimizing the Risk of Bubbles in Resin

When working with resin, it's important to have the right tools and equipment to minimise the risk of bubbles in your artwork. Here are some extra tips and tools that can help maintain optimal working conditions for resin projects:

  • Heat Mat with Controllable Thermostat: Using a heat mat with a controllable thermostat can help regulate the temperature during the curing process. Maintaining a consistent temperature can reduce the likelihood of bubbles forming in the resin.
  • Toothpicks: Keeping toothpicks on hand is useful for removing any small air bubbles that may arise during the mixing and pouring process. Simply use the toothpick to gently pop any bubbles that appear on the surface of the resin.
  • Small Mixing Sticks: Utilizing small mixing sticks allows for precise and thorough blending of resin and hardener, minimising the introduction of air into the mixture. This can help prevent bubble formation before pouring the resin into moulds or onto surfaces.

By incorporating these additional tools and tips into your resin art process, you can create a suitable environment for producing bubble-free artwork.


To sum it up, preventing bubbles in epoxy resin can be challenging but not impossible. By following the tips and techniques mentioned in this blog, you can significantly reduce the production of bubbles in your resin projects.

Experiment and find what works best for you. Everyone's experience with epoxy resin is different, so don't be afraid to try out different techniques and materials to see what gives you the best results. Patience and attention to detail are key, take your time when working with resin and pay close attention to every step of the process. Rushing can lead to mistakes and more bubbles.

If you're passionate about resin art or want to learn more about this fascinating medium, Contact Us on Arts Shala today for a community of artists and crafters who share tips, tutorials, and inspiration to help you take your resin creations to the next level.
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