Auto body repair & detailing: patching body panels, 3m adhesive, rusty metal

Question
What is the procedure for using 3m adhesive to glue a body panel patch?  How much rusted panel do you remove.  Is body panel put on outside or inside of vehicle metal?  I am replacing pickup truck box wheel openings that are rusted.
Thanks

Answer
Hello Rj! Grind back the paint at least 3 inches past the overlap on the body with 36 grit. Grind the face of the repair panel, also. Leave at least a half inch overlap on the patch panel, but no more than an inch. Cut away all the rust, any rusty metal left will immediately cause rusting of the new panel. After properly fitting the panel, apply adhesive, liberally. Use rivets on the face, and clamps to hold the panel in place while curing. Apply glue over the overlapping panels seam, and smooth with a bondo spreader. Oh, and apply the patch panel to the outside. The only other suggestion I have, is to use a panel flanger on the old box opening, but this takes a really close cut of the panels- a half inch, to be exact. if you don't feel comfortable with that, then just stick to the basic overlap. Bill