What do you do when you have quite a bit of rust on the underbody of your car? I guess I am a bit unexperienced with dealing with rust on a car, being in Arizona we just don't see much of it.

My R/T that I just bought came from Masschusetts and before that Michigan, so it has been battling corosion all it's life. I'm sure being by the ocean in Masschusetts didn't help anything.

It's not on the body, but there is quite a bit under the car. What should I do, if anything, to treat it? Must I be worried about it getting worse or "spreading?" Or now that it is in Arizona will it just dry out and stay dormant?

 

Clean area, sand/scrape if need be, finish by a hand painting of any issue areas with POR15. Forget about it afterwards, especially in Arizona.

Will it still rot if nothing it done? Yes. Get it wet, it will keep going. Thus, stop it and you're done. Do nothing and you're done too... just a different type of "done."

Also, check the body 'trouble areas' just in case.

IndyDurango

 

You can add more complete protection to all that he said by spraying or dousing the affected areas with a product called "The Must For Rust" found at the Home Depot. Use it between Indy's "scrape" & "finish". I've used it many times - on the frame of an in-progress-being-restored Jeep CJ7, rusting chrome wheels, my own Jeep very recently after gutting the interior, and many miscellaneous projects. Don't know the effect on wires & rubber parts, so read the directions & have at it. It works.

Edit: Search "rust" on any Jeep forum and you'll find tons of ideas - but be prepared to be overwhelmed!!!