K.C. Body Shop Supply

Call Us (773) 306-2805

How to: Prevent and Fix Auto Paint
Pimples, Bubbles, and Bumps

How can I get rid of bubbles in my auto paint surface?

There are many causes of auto paint bubbles and other similar conditions. The only ways to remedy it are to remove the affected area and refinish it or, in extreme cases, strip to the bare substrate and apply a completely new finish.

In this article, I’ll explain everything you need to know to prevent auto paint bubbles and fix them when they happen:

  • What causes bubbling on the painted surface of my auto?
  • How can I repair a bubbled auto paint surface?
  • How do I prevent pimples, bubbles, and bumps when I paint a vehicle?

What causes bubbling on the painted surface of my auto?

Swelled areas appearing as pimples or bubbles in the topcoat film can appear months, or in some cases, up to a year, after it was applied.

Five different things can cause it, including:

  1. Moisture trapped beneath the paint film. This happens because of:
    • Too little drying time after wet sanding
    • Contaminated applicator air lines
    • Spraying in extremely high humidity.
  2. Using the wrong — or poor quality — thinner or reducer.
  3. Trapped solvents, which happens when you apply heavy coats of paint and allow too little flash time between coats.
  4. Allowing too little dry time for undercoats before applying the topcoat.
  5. Applying paint over grease, oil, or rust.

How can I repair a bubbled auto paint surface?

There are two ways to do this:

  1. Remove the topcoat from the affected area and apply a new finish.
  2. In extreme cases, the impacted area must be stripped to the bare substrate before refinishing.

How do I prevent pimples, bubbles, and bumps when I paint a vehicle?

There are five things you can do:

Taking these steps will help prevent bubbles, pimples, and bumps from forming after painting an auto.