How to Get Bubbles Out of Your Epoxy

Epoxy is a versatile medium for arts and crafts, jewelry, pendants, cutting boards, decorating tumblers, sealing photographs, and artwork. Both DIY enthusiasts and tradesmen use it for countertops, river tables, tabletops, and countless other projects. It is durable, allows for vibrant colors, and lasts for years.

One common challenge when working with epoxy is bubbles that either remain trapped or form after application. Using cheap epoxy and hardener usually results in poor quality finishes, so it’s best to invest in a quality, preferably American-made product. Epoxy is thick (viscous) at lower temperatures, which makes it more prone to trapping bubbles during mixing. To minimize this, it’s recommended to warm the epoxy to between 75–85°F for better bubble release.

There are two main causes of epoxy bubbling or outgassing:

1. Unsealed or Improperly Sealed Substrates:
   Porous materials can release air or moisture into the epoxy as it cures, causing bubbles or dimples—this is called outgassing. Epoxy typically takes time to set or form a film, allowing penetration into porous surfaces and resulting in these voids. Outgassing is often visible under the glossy finish and can be difficult to repair. Even when a substrate is sealed with a thin epoxy coat, outgassing can continue when applying a second coat, as the epoxy penetrates further during curing.

2. Bubbles from Mixing:
   Improper mixing or working with cold epoxy increases bubbles trapped in the resin.

These issues can be effectively prevented by using fast-set epoxy products that dry quickly enough to form a film and seal porous substrates before outgassing occurs. However, fast-set epoxies tend to be more brittle and can yellow (amber) over time due to their hardener chemistry.

For superior results, consider using iCoat 2112 Penetrating Wood Sealer as a primer. It dries quickly, can be multi-coated and sanded if needed, and is fully compatible with epoxy. It seals porous substrates well, preventing outgassing and bubbles from spoiling your project.

To reduce bubbles trapped during mixing or application, use a trigger-start propane torch to lightly pass over the epoxy after pouring. When applying multiple layers, torch each layer to release bubbles before adding the next. Keep the torch about 1 inch from the surface and avoid lingering in one spot to prevent burning the epoxy. Torching every 10 minutes for the first 30 minutes after application is optimal.