spent a lot of time grinding out the rust with electric drills and wire discs. we sawed away some of the panel that remained jagged.
we initially tried the expanding foam as a first layer. it didn't hold up at all. we then wound up stuffing the holes with newspaper to create a frame for the fiberglass cloth to rest over and harden.
basically this didn't work so well either, and the final job looks much like paper mach?. still driving this thing around. it's by far the ugliest car on the road, still, and will probably never pass inspection.
i think if i were to redo it all with kitty hair it would go much better, but who knows.
here's some pics:
my friend gio on the left, me on the right, proudly displaying our dollar store tools.
Next time try getting some pieces of sheet metal, and a riveter, and a drill to make holes for the rivets. Cut the metal to the shape and form of the car, clamp them underneath the good part of the panel, drill holes for the rivets, and rivet that piece of metal on. Trim the metal at the bottom if needed, then use some Bondo to smooth out the front of the panel with some sand-paper. Doing that method, you could have the car looking stock again.
But your method does hide the rust at least!
On the never-ending quest for better gas mileage...
uh, well, i gotta hand it to you for getting it done. It ain't pretty, but it works I guess. What I would do is go to a junkyard and cut out a piece that
will fit that area from the same model year (or shape a piece of sheet metal to fit). Make sure you can overlap the metal on every edge, then tack weld it in place, then weld it up and grind down the welds. Than you spend some time to smooth it out with bondo, cheese grater, sandpaper (80-120 grit), and a DA. Prime it with etching primer on the bear metal area, then with regular primer or high build primer. More sanding (with finer grit - 220 and higher grit). Then paint with bc/cc. And finish off with wetsanding (1200-2000 grit).
It'll look like my blue car (click on '91 Eclipse GSX'). If you look at the front of the rear wheel well where you did work on your civic, I did similiar work there. I think I spent the most time in that area. Amazing what bondo can do. That area was crinkled big time.