Should the Original Paint Be Scraped Off Before Repainting?
2 Answers
Repainting requires the removal of the original paint because if the old paint is not treated, the new paint will not adhere properly and may peel off when blended with the old layer. If the original paint is left untreated, even if the new paint looks perfect right after application, it can easily come off when washed with a high-pressure water jet during car cleaning. Leaving the original paint untouched will also result in the repainted area being higher than the surrounding surface, which is aesthetically unpleasing. Typically, the entire clear coat layer is sanded off before applying the base coat, followed by a new clear coat. The electrophoretic coating serves as the primary anti-corrosion layer of the car; if damaged, the steel panels may gradually corrode. For minor scratches that don't reach the primer, polishing with a rubbing compound may suffice instead of repainting. However, if the primer is exposed, the original paint must be polished off before applying a new coat.
I learned a lot while doing my own car paint color change. Whether to scrape off the original paint before applying new paint mainly depends on the condition of the original paint. If your car's original paint is still intact, with no cracks or rust, simply sanding the surface with coarse sandpaper is sufficient, as this helps the new paint adhere better. However, if you accidentally spray over problematic paint surfaces, such as those with corrosion or peeling, you must completely remove the old paint; otherwise, the new paint will bubble and peel off quickly. I remember last time I skipped this step to save time, and I had to redo the job three months later, costing me even more money. Cleaning is crucial throughout the process—details like blowing away dust and grease cannot be overlooked, and good ventilation is also necessary to avoid affecting the paint's drying.
