Well I bought a 1991 camaro about 5 months ago and it was suppose to be in good shape. I've just been able to get around to it and while doing an oil change I noticed the bottom of the car is starting to rust. On the driver side floor board its rusted straight through. Anybody have any tips on what's the best way to replace the rust?

 

cut it out and patch it, either with shaped steel or a piece from a donor car

You have to figure out why it happened in the first place before you can fix it though. If you have T-tops and they're leaking, that has to be fixed first.

 

OK thanks. The places it ain't rusting to bad just beginning would it be fine to take a wire brush to it and spray it with something to prevent rust? Sorry new to the car work only 14 and haven't ever done body work just engine work.

 

I've had pretty good luck over the years with cleaning it real good, a coat of Rustoleum aluminum paint, then a top coat of body color or flat black paint. That aluminum paint seems to penetrate and seal it up better than most other stuff. I've spent a lot of money on POR15 with mixed results, not impressed with the stuff. For the rusted through parts, not much to add to the above post, cut it out and replace. Also there is a section behind the lower part of the front fender on the main body that is about always rusted though, take a look if you get that deep.

 

Not always true. A car doesn't have to be leaking to be rusting. The newest of these cars is almost 24yrs old. My 89 is a tad over 26yrs old according to its invoice build date.

As to the OP. Your methods for patching are like above. Weld in a piece from a doner car, or shape steel and weld it in.

If you do not have the ability to weld and its a small spot, say a quarter, or silver dollar sized hole then you can remove the carpets and just have an exhaust shop cut out the rest, grind the surface rust till clean, then weld in a patch. Which you can then seal and paint like normal.

Or you can clean it up with a wire wheel, seal, then use body glue to glue in a patch if you really are that tight on funds.

 

Click on my photo album. On the bottom are photos of what was done with mine. Cut out, layer with netting then pour in an epoxy, fiberglass blend. My uncle has been in bodywork 40+ years. He said its a 'recipe' many (New England) body guys did to their cars back in the 80's. As you can see, the repair can be shaped as well.