underside rust

[adriatic]

found a 91 s13 that was in a moderate frontal accident (looks completely repaired now) ...somehow has odometer problems... and has light spoiler rust... all of these don't really concern me.

however, there is about a 4x4 inch spot of rust on the underside of the car next to the frame rail - about as far back as the door (so midway back)..

the rest of the underside looks just fine, frame rails, etc.. the body has been repainted and looks great

they're asking 1500 for this car and my question is, can the rust i described be fixed (and how?)? or will it spread and kill the whole frame? I want to make this car an sr20 daily driver...

every s13 I've looked at has some sort of rust on its underside, so this is really frustrating.

[adriatic]

i've done a search and couldn't really find much other than someone saying to sand/clean/coat/weld it.

[NISTECH]

that is pretty much your option but it really depends on how thick the rust is. if it is only surface rust you can sand it and coat it with undercoating. if it has penetrated through to the other side of the metal it would need to be cut out and have a replacement peice welded in.

[adriatic]

i got under the car just enough to see it, it looks slightly more involved that simple surface rust, maybe an inch deep at the maximum... if i were to have it cut out and welded up -

-how efficient would this be?-how much would it cost (ballpark)-how would this effect the driveability with an sr20 powerplant

in YOUR opinion, what would you do?

[navysnail]

is it just in the floor pan or somthing, id cut and weld it, i wouldnt think it would affect driveability at all

[NISTECH]

my self I wouldnt buy it ,but keep in mind where I live there are 100 more within 50 miles for sale that likely wont have rust. I live in california so rust is usually never an issue unless the car came from back east. You may not have those options.