How to Solve Paint Bubbling?
3 Answers
Use a needle to puncture the bubble to determine its depth. When the bubble occurs between paint layers, sand down the defective area to expose the intact paint layer and then repaint. Smooth it with soapy water and seal it with two-component surfacer.
I've been driving for almost thirty years and have dealt with numerous paint bubbling issues. The most common cause is not cleaning the car body surface properly before painting, such as rushing to paint when there's dust or oil stains, or when there's still moisture in the underlying layer that hasn't evaporated completely. Once, my friend's car door had bubbles, and I helped him by first sanding off the bubbled paint layer with 800-grit sandpaper, then scrubbing the underlying layer with industrial alcohol, and letting it dry for three days to ensure no moisture remained. When repainting, it's important to apply thin layers multiple times, with a twenty-minute interval between each layer. Finally, we chose a highly weather-resistant water-based paint. The rainy season in the south is the most problematic time for painting. Once, I didn't pay attention to the humidity, and it started raining right after I finished painting, causing the entire painted surface to bubble up like toad skin, forcing me to redo the whole thing.
Last year, I encountered bubbling issues during the refurbishment of my used car. After inspection at the repair shop, the mechanic explained that the underlying metal rust wasn't properly cleaned, causing the rust spots to spread and lift the paint surface. They thoroughly cleaned it with rust remover, applied epoxy anti-rust primer to seal out air, and then repainted the topcoat. For DIY repairs, they recommended preparing sandpaper, degreaser, and spray paint. First, puncture the bubble to observe the inner layer color: if there's moisture, dry it out; if rust spots appear, sand down to bare metal. Never use quick-dry touch-up paint as a temporary fix—I tried it and the bubbling area doubled, ultimately costing more for rework.
