How to Sand a Car Door Before Primer and Paint: Complete DIY Guide

Prepping a car door for primer and paint starts with sanding—and doing it right makes the difference between a smooth, professional-looking job and a lumpy, peeling mess. This SEO-focused guide explains exactly how to sand a car door step-by-step using the correct grits, tools, and techniques, whether you’re fixing a dent, respraying, or starting from bare metal.

Why Sanding a Car Door Is Crucial

Sanding removes the old finish, levels surface imperfections, and creates a rough surface for primer and paint to grip. Whether you're repainting or spot-repairing, sanding ensures adhesion and long-lasting results.

Best Sandpaper Grits for Prepping a Car Door

• 180 grit sandpaper: Removes paint and levels filler.
• 320–400 grit sandpaper: For feathering edges and smoothing before primer.
• 600 grit sandpaper: For final sanding before basecoat or clear coat.

Step-by-Step: How to Sand a Car Door

1. Wash and dry the door thoroughly to remove dirt and oils.
2. Use 180 grit to sand off any old paint, clear coat, or rust. Focus on filler or damaged areas first.
3. Switch to 320–400 grit to feather out the edges of the repair and prep surrounding areas.
4. Use 600 grit to refine the surface and remove any sanding marks before primer.
5. Wipe down with wax & grease remover, then apply primer.

Pro Tips

• Use a sanding block for flat areas and hand-sand curves and door edges.
• Feather your sanding zones to blend new paint into old paint smoothly.
• Work in good lighting to catch imperfections before primer.

Common Questions

• Can I skip 600 grit before painting? You can paint after 400 grit, but 600 gives a cleaner, smoother finish.
• Should I wet sand or dry sand? Wet sanding is better before final paint; dry sanding works well for primer prep.

Watch & Learn

Grab the exact sandpaper you need at eQualle and explore more auto body tutorials on our DIY blog.