What Causes Bubbling on Car Doors?
2 Answers
Reasons for paint bubbling on car doors: 1. Paint quality and application conditions: Generally caused by factors such as poor paint quality, or non-stringent painting conditions and processes. To address paint bubbling, the affected coating needs to be sanded down to remove all solvent bubbles, followed by repainting. 2. Excessive paint thickness: Applying paint too thickly can also lead to bubbling. Lack of attention during the painting process or limitations in the technician's skills often result in an overall paint layer that's too thick, causing the paint to sag. Additionally, improper handling during subsequent polishing can also contribute to paint surface bubbling.
The most common cause of door bubbling is rust forming on the metal beneath the paint, where water seeps in and corrodes the panel layer. This issue is particularly severe at the bottom of doors where water tends to accumulate. I've encountered many cases where vehicles parked long-term in humid environments or washed without proper drying, leading to blocked drainage holes and trapped moisture that gradually corrodes the body. Start with simple checks: press on the bubbles to see if they feel soft or if rust particles fall out, then inspect door frame gaps for damage or clogged drainage holes. Repairing is quite labor-intensive—grinding off rust, reapplying primer, and repainting—costing anywhere from a few hundred to over a thousand yuan. Neglecting it can worsen into widespread bubbling, affecting door operation and even structural safety. For prevention, park in dry areas away from trees, dry door seams after washing, and regularly clear drainage holes to ensure they're unobstructed.
