Well, here is what I did. I cut out all the rust, then welded a 16 gauge panel on the inside. I then welded a 22 gauge panel to the outside, and fabbed up a frame rail extension. I used seam sealer like it was going out of style. Keep in mind, this is the first time I have ever welded on a car, and like the third time I have welded ever. I can say, it is very sturdy, maybe even more so than the other, non rusted side.