Why Do Bubbles Appear in Car Paint?

[LaHarrison]

Bubbles in car paint occur due to excessively high paint viscosity, applying too thick a coat at once, inadequate filling of pores trapping air, especially on porous substrates without a proper sealer primer; or from excessively high spraying air pressure introducing too much air into the paint. Below are relevant explanations: 1. Car Painting: Car painting refers to applying a layer of paint to the vehicle's surface to protect it. Automotive paint typically uses baking enamel. In car manufacturing plants, after the frame and body are welded, the next step is painting. Types include standard paint, metallic paint, and pearl paint. The painting process involves applying putty, sanding, and spraying. 2. Car Paint Types: Standard paint; metallic paint; pearl paint; clear coat; matte paint. Paint contains various solvents with benzene compounds like toluene and xylene. Thinners contain toxic industrial solvents like ethanol and butanol, some extremely hazardous such as methanol.

[DelLayla]

I've been in the paint spraying business for over 20 years and have seen too many bubble issues. The main causes are unclean surfaces where residual oil stains or dust get trapped during spraying, forming bubbles. High environmental humidity is another problem—moisture can seep into the paint layer, causing bubbles to expand. Or, spraying too thickly or too quickly can trap air as the solvent evaporates. I once worked on a car where the owner sanded it but didn’t fully degrease, resulting in a dense spread of bubbles after spraying, forcing me to redo the job. Remember: always clean the surface with degreaser before spraying, apply thin and even coats, and let each layer dry completely before the next. Choose sunny days for painting, and mix the paint ratios correctly to avoid wasting materials. Over time, you’ll learn that prevention is key—otherwise, repairs can be a real hassle.

[DelMackenzie]

When doing DIY car paint spraying at home, I've encountered bubble issues several times. That time when I was painting the rear lid of my old car, I noticed quite a few bubbles after spraying. Upon reflection, the main culprits were my laziness in not thoroughly cleaning the surface beforehand, leaving behind dust and oil stains. Additionally, it was a humid and rainy day, and applying the paint too thickly caused bubbles. The lesson was profound: don't rush the process; always take the time to sand and wipe the surface with alcohol, and choose dry weather to apply thinner layers. Otherwise, not only will the appearance be unsightly, but paint will also be wasted. Now, I always check the environmental humidity in advance and maintain the right distance with the spray gun. If bubbles have already appeared, they need to be sanded down and repainted, preferably with the help of professionals. After all, DIY is meant to save money, but if not done properly, it can end up costing more effort.

[McLeonardo]

I've only been learning car painting at the repair shop for two years, and my master has taught me about bubble causes. Simply put, when there's too much surface dust or moisture during painting, it gets trapped inside and forms bubbles; also, air isn't fully expelled when spraying too quickly. Common causes are inadequate cleaning before painting or the primer not being fully dry. During operation, I need to pay attention to controlling speed and environment. When bubbles appear, rework is necessary, which is quite annoying.