Ask I-CAR
Ford
Per I-CAR curriculum developed in cooperation with the vehicle maker: “When making outer panel sectioning repairs:
- the repair joints should be made using a butt joint with backing. Ford service information states that where possible, create a backing using a portion of the old panel.
- Ford service information does not provide a recommended size for the backing for the weld joint.”
Check out the I-CAR Collision Repair News article: What's A Ford Lap-Joint Backer Plate?