I've decided to drop the exhaust, driveshaft, loop and clean/paint the floorpan and frame rails. Since it is winter I am fairly restricted to the garage. Therefore I really cannot use a pressure washer or much water. I plan to prop up the trans, then remove and clean the trans crossmember; it seems to be the worst. Otherwise I think I will just be degreasing places here and there. I have Super Clean purple cleaner, the skin-eating kind. That should be sufficient to remove any oil would you think? Afterward I guess I will use my die grinder with a wire wheel to prep the surface and then get ready to either POR or Rustoleum it. There is only a little surface rust where it was never undercoated. Car is rather nice underneath already but I would like it quite nice. Any tips appreciated.
I've been using rustcure on mine and have been very happy with the results. You can put it in a spray bottle and use the course scotch brite to rub the area. It will desolve the rust pretty easily and you can wash the residue off woth soap and water. If it's lightly rusted it can go on and leaves a hard black oxide finish that you wash and then paint.
I did the trans crossmember, trans mount, and the frame rails under the rocker panels this weekend. Heat gun to soften it working about 6" at a time, plain ole putty knife for scraping, then a good wipedown with kerosene and a washdown with Super Clean. Worked good but it is time consuming. The undercoating comes off in ribbons mostly though some areas were dry and chunky. Newspaper catches it quite well. I decided not to do the floorpans because the heat would probably wreck the carpet padding and I don't want to pull the interior. I will just scrape away any old loose stuff, wire brush surface rust areas and recoat nicely with fresh undercoating. Will be getting into the wheelhouses and frame rails moving forward soon.
