Seam sealer is a flexible, paintable compound used to seal joints, seams, and gaps in automotive panels to prevent water, dust, and air from entering. It’s commonly applied in areas like door edges, boot seams, and floor pans to protect against rust and corrosion. Seam sealer maintains the integrity of factory welds and repairs while helping to reduce noise and vibration. Available in brushable, sprayable, or caulking forms, it's an essential part of long-lasting vehicle body repairs.