Difficult since I only have the cheapest Harbor Freight Welder and the metal is pretty thin, so I had to make a series of small tack welds (to minimize the number of holes I would blow through it), then caulk it up, the cover up the whole thing with the above pictured self adhesive flashing (which I highly recommend keeping around). This is what it looked like with the bumper removed: This is what it looked like when I removed all the loose stuff: This is what it looked like after I hit it with an angle grinder wire wheel attachment: I happened to have a piece of sheet metal that was the front of a washing machine. I used some of that to make a repair plate. This is what it looked like after I welded it on; I covered that with that self adhesive aluminum flashing that I show above, then caulked it on the inside. Once the caulk stops stinking, I'm going to put some more of that self adhesive aluminum flashing on the inside as well. I made no attempt to prime or paint it, seeing as to how the flashing stuff will probably be way better anyway. It also covers up all the little holes that I didn't cover or made while welding. For some reason I did not take a picture of that one with the foil on top of it.The bumper covers all of this up so there is nothing to see from the outside. It wasn't the only rust hole I fixed either: This one patched and with the flashing on it: This self adhesive flashing stuff is really sticky and has a thin (~1mm??) layer of something like roofing tar on it that make it particularly good. I would not expect rust in this area on most Escorts. I think this in only happening because in 1998 the car was hit real bad in the back and that whole vertical piece was cut out and a new one was welded in.