In many cases, removing the suspect sheet metal item, is a matter of allowing better access for assessing the rust damage, removing the damaged area, situating yourself to do the welding and the convenience of top-dressing/back-dressing the welds. Oftentimes, forgoing removal of the problem piece, requires more time, in order to perform the repair, than the time it would have taken to remove it and repair it more efficiently and effectively at the onset.
