What Causes Small Bumps After Car Painting?
2 Answers
If there is water remaining in the spray gun, darker spots will appear on the paint surface. Another possibility is water mist splashing onto the freshly painted surface before it dries. In rare cases, improper putty application may cause bubbles or water spots that cannot be removed, requiring repainting. Below is relevant information about painting: Spray Pattern: An ideal spray pattern should be symmetrical with evenly distributed atomized particles and clear edges. Only a minimal amount of overspray should exist beyond the pattern edges. Lower atomization pressure helps achieve correct, uniform spray patterns while reducing bounce-back and overspray. Spraying Technique: Maintain the spray gun perpendicular to the workpiece surface during application. The distance between the spray gun and the surface typically ranges from 15~30cm, adjusted according to the surface angle. For wetter, darker, and thicker coatings, reduce the distance; for drier, lighter, and thinner coatings, increase the distance.
Last time I helped a friend with spray painting, I encountered these tiny dots. At first, I thought it was an issue with the paint, but later realized it was because the surrounding area wasn't cleaned properly, allowing dust and fibers to settle on the paint surface. If the spray gun's pressure isn't adjusted correctly or the distance is too close, it can also cause bumps. The paint material itself is crucial too – if not stirred evenly or mixed in the wrong ratio, particles can form during curing. Primer preparation can't be overlooked either; if sanding isn't thorough or there's residual grease, the paint won't adhere properly. I recommend sanding off this layer of paint and respraying in a dust-free booth. Remember to wipe the car body clean with a tack cloth before painting.
