How to Repair Rusted Bottom of Car Door?
2 Answers
Use a grinder to sand the rusted area, thoroughly removing all rust. Spray some expanding foam, then trim off the excess foam. Wipe clean and apply a layer of rust inhibitor. After the adhesive dries, use a grinder to smooth the edges, then apply body filler and sand with sandpaper.
In my years of driving experience, rusting at the bottom of car doors is quite common, especially when water accumulates in the door channels after rain and isn't drained properly. The solution requires a steady approach: First, put on gloves and a mask, and work in a well-ventilated area. Use a wire brush or sandpaper to thoroughly remove the rust, scraping away the corroded metal to expose a clean surface. If there are small holes from rust, apply automotive-specific filler (like repair paste) to smooth and fill the gaps, then level it and let it dry for about a day. Second, once the filler has hardened, sand it smooth with fine sandpaper, and spray a rust-proof primer to create a protective layer—apply a thin coat, let it dry, then add another for better durability. Third, choose a spray paint can matching the car's body color for the topcoat, applying it in layers to prevent drips. If the rust is too deep or the door panel is extensively damaged, it's best to take it to a repair shop to weld on new metal sheets—costly but safer in the long run. Prevention is key: always dry the door channels after washing, ensure drainage holes aren't blocked, and avoid letting water sit to prevent re-rusting. This process requires patience, and good craftsmanship ensures lasting results.
