Startlingly fast rust problem


#1

I have a 1999 Dodge Caravan with about 128,000 that began its life in Wisconsin but spent the last 3 years in Montana. When I moved to Montana there was no rust and the body was in good shape. About a month ago I spotted the first signs of rust along the very bottom of the car under the passenger sliding door. it was bubbly paint and a little bit of rust poking through. I intended to take care of us after the snow season. About two weeks later, that little spot of bubbly paint was gone… so was about 14 inches of that bottom runner. It completely rusted out. Gone. Now I’m freaked. I can’t believe how fast it deteriorated and disappeared, and now I’m deeply concerned about the rest of the vehicle. It’s paid off, so part of me just wants to try to keep it clean, run it until it falls apart or dies. I just installed a new transmission last summer, so I was hoping to get a lot of life out of this now paid-off van. Can anyone give me advice on what I could do to stop or slow the rust, or whether I should try to dump the van ASAP before it’s so rusted that it’s unsellable. Thanks.


#2

Unfortunately the only way to stop body rot is major surgery.

You can slow it by grinding off (to the metal) all that you can, filling with filler (bondo, a panel piece, or fiberglass), priming and painting. The better you do at this is the more you’ll retard the propogation of the rot.


#3

It’s not so much that it rusted out fast, you just couldn’t see it happening. It’s like mice- if you see one, you know you have a BIG problem. Those bubbles were a sign of the underlying problem. It was rusting from the backside out so by the time the paint was affected, the metal was nearly gone.

Sometimes, the cure can kill the patient. To cure the problem may cost more than the vehicle is worth. In that case, you may be able to retard the process enough to get your useful life out of it before it falls apart. Only an inspection of the rotted areas will tell how far it’s gone and what can be done.

I staved off the cab corner rot in an old pickem up I had by removing the loose stuff and coating it with POR15 inside and out. I then riveted some small patch panels over the sealed area and painted them to match. I sold the truck years later without any additional decay in those areas. YMMV.


#4

Make sure there aren’t eny exhaust components touching the body. This is the usual cause of very quick rusting. It could also be that you scraped the bottom of the car on something at some point, leaving a patch of bare metal that is the kerenel for your rust problem. I’d take it to a body shop where they can at least get a handle on how extensive the problem is. If it hasn’t spread too quickly, you may still be able to grind off all of the rust and recoat it.

Where are you in Montana? I think only a couple places out in the eastern part of the state use salt on the roads. In the western part, they mostly use sand (if that) and it’s actually a pretty good place for preserving cars. Way better than many parts of Wisconsin for sure! Just wash the bottom of your car fairly frequently during the winter and you should be fine-- I’ve got many cars that are much, much older than your Caravan that have spent their whole lives in MT and have no rust at all.


#5

I suspect the rust started in Wisconsin with road debris, salt, etc building up somewhere in the undercarriage and never really getting washed off. That’s why I’m hoping it just doesn’t continue to spread. I’m hoping the damage was done a long time ago and isn’t as serious or widespread as thought.

Thanks for the advice!

-jsa


#6

You may have, or have had, clogged drainage/weep holes under the rocker panels. Before anymore of the car disappears, check along the underbody below the doors to see if there are weep holes for door drainage, and whether they have become clogged with tar, sand, or whatever. If so, clean them out and spray with rust inhibitor (but not anything that will clog the holes again).


#7

There was a show on the History channel last night. It’s premise was what would happen to the world if Man wasn’t here anymore. They were talking about cars. Their estimate was that in would take 5 years for cars in places like the NE to completely rusted (assuming they are left in the open). After 20 years all that would be left is the frame and engine. After a couple hundred years…a pile of dust.


#8

Rust never sleeps. Once it takes hold, the only way to stop it is to eliminate exposure to moisture. Unless you now live in a very arid climate, the rust is advancing. I grew up in WI and have spent many years battling rust and restoring cars. Battles can be won but the war will always favor rust.


#9

good call turbo… it’s not worth repairing, to costly.