How to Prevent and Fix Micro-Bubbling?

A well-known and unfortunately frequent issue for painters and coating professionals, micro-bubbling can cause significant delays on a worksite and severely impact the quality of the final finish. Here’s what you need to know about micro-bubbling: its causes, how to prevent it, and how to correct it if it has already appeared on your surface.

What Causes Micro-Bubbling?

Micro-bubbling refers to the formation of numerous tiny air bubbles during the application of coatings or paint. Not only does it look unappealing, but it can also be a disaster for the subsequent painting stage, making it a real headache on a project.

Unfortunately, there are multiple causes of micro-bubbling:

• In 20% of cases, it occurs due to outgassing from the substrate, often when the surface is too humid or has not been properly dusted. This highlights the importance of thorough surface preparation, including cleaning, sanding, and dust removal before applying the coating.
• However, in 80% of cases, micro-bubbling appears during renovation work, particularly when applying coating over old paint or an overly sealed surface. Often, the issue doesn’t appear immediately but during the second coat of coating.

Micro-bubbling is therefore a physical reaction of the substrate to certain conditions rather than a flaw in the coating itself.

How to Prevent Micro-Bubbling?

Once you understand why micro-bubbling occurs, it becomes easier to prevent it.

Beissier experts recommend using a spiked roller or a wallpaper perforator roller. In his demonstration, the expert specifically used a Fakir roller.

This tool pre-perforates the surface before coating, recreating the necessary micro-porosity in the substrate. This ensures proper gas exchange, effectively preventing micro-bubbling—an ideal solution for renovation projects.

For new surfaces, however, it is essential to apply a thin primer coat before the coating application to ensure proper adhesion and avoid bubbling.

How to Fix Micro-Bubbling?

If the surface was not properly prepared and micro-bubbling has occurred after application, don’t worry—it can still be fixed.

To correct micro-bubbling, follow these steps:

1. Use a spray bottle filled with water and a slightly damp coating blade.
2. Once the coating starts to set slightly (usually a few minutes after application), lightly mist the surface with water.
3. Smooth out the bubbles by pressing them down with the coating blade.

Alternatively, if the coating has already dried with micro-bubbles, you can:

• Sand the surface to break the bubbles,
• Reapply a skim coat using a traditional coating blade for a smooth, even finish.

By following these techniques, you can ensure a flawless result and avoid unnecessary time-consuming corrections on-site.