Gary --

I did exactly this to an '86 245. The rusted area was under the driver's seat from the rocker to the tunnel. I cut a good section from an '81, cut the rusty section out of my car, and welded in the piece. The job came out very well, and has been fine for almost three years.

Several comments. First, you must remove the seats and carpet. Be prepared for serious scraping of the paint and undercoating before welding.

Second, be sure to move or protect any wiring harnesses. I didn't do this, so had some electrical repairs needed before the job was finished.

Third, be alert to the fuel lines and brake lines under the floorboards on the left of the driveshaft. I unbolted them, pulled them aside, and wrapped them in soaking wet towels before welding.

I welded with an acetylene torch that did the job, but also warps the metal. A gas welding flame dumps the heat in too slowly, so everything gets hot -- including the adjacent undercoating and fuel/brake lines (hence the wet towels).

If you can, use a MIG welder. (I've since bought one.) Finish the job with primer, several coats of good enamel, and undercoating or roofing tar.

I looked unsuccessfully for an aftermarket source of 240 floorpans. However, I'm told Volvo sells replacement floorpans at a significant price.
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