After cleaning up the welded-in rust patches in the rear fenders I needed to use some body filler to blend in the panels to the body lines. I applied a thin coat of Metal 2 Metal body filler over the patches. Later I will sand off much of the filler and hopefully leave just enough to make the patches invisible and restore the appearance of the fender lip. On the left rear fender I applied the filler in two stages as I worked down from top to bottom. I first swiped the filler onto the fender lip from the body crease right to left, then from the crease toward the fender from left/center to the right.
On the right fender I used more filler in order to finish off the end just behind the wheel well, which I had previously built-up using body solder. In the hot July Texas sun the filler cured quickly on the sheetmetal, and there were even some bubbles. I had to work quickly and it was difficult to get a smooth result, which means more sanding later.
Later in the day I did a quick sanding and then cleaned off the dust and applied a second coat of filler to both sides.