It is sometimes viable to repair rusted sections by removing the rusted area and replacing it with a steel patch welded or brazed into place. The same precautions regarding heat etc., apply as for using body solder, plus extra care with heat build-up warping the rest of the panel. Use of a MIG welder is preferable, with oxy- acetylene brazing or welding not really recommended. Cut away the rusted section as carefully as possible to minimise further damage. A small cutting disk in an angle grinder or power jigsaw can be used if care is taken to check no.
