4 When excising the driprail from the body, Gillis leaves about 1/8-inch of the original material so he has extra metal to work with when grinding the edge even and straight. If you cut away too much material on your first cut, you can screw up the line. With the driprail removed, the roof panel will separate from the rest of the driprail molding. The two panels are then clamped together to close the gap again, and then you can begin stitch-welding the seam. Make sure the welds go deep enough so that you can grind them down and not have any holes appear.