those strips are called the ditches, where the panels are joined together. The material is supposed to stay soft. Under the sealer are spot welds where the panels are welded together.
In addition to repairing the weld area, proper sealing of the joints is essential to a quality repair. Sealers are intended to prevent wind noise, water, dust and exhaust fumes from entering the vehicle and also perform as anti-corrosion barriers. Sealers need to be applied to such areas as door and rear compartment lid hem flanges, wheelhouse, quarter outer, floor, cowl, roof and various other panel-to-panel attaching points. The following joint sealers are recommended for use depending upon the application:
- Brushable Seam Sealer - A sealer intended to restore the original brushed seam look. It is used to seal lap joints in sheet metal that are spot welded, such as on floorpans, cowls, trunk seams, etc.
- Joint and Seam Sealer - A firm setting but flexible sealer for interior and exterior joints and seams.
- Drip-Check Sealer - A heavy bodied sealer designed for use on exposed seams.
Sealers should remain flexible after curing and must be paintable. Follow the manufacturer's directions for use of materials selected.
Any damage to originally sealed joints should be corrected by resealing. Along with attaching points of new panels, open joints which require bridging of sealer to close a gap should be sealed using a heavy-bodied sealer.