Expert: William Forster - 11/26/2007

Question
QUESTION: Hi William.Just purchased a new dodge grand caravan. I would like to know if rustproofing is necessary or recommended by an expert. Dealers (as you know) offer a rustinhibitor, as well as underbody protection (black sticky stuff) Is any of this stuff really needed or maybe just an oil spray once a year. I live in Ontario Canada--heavy salt is on the roads in winter. I plan on keeping the vehicle for 15+ years if it lasts that long. They even offer the electronic gadget that hooks up to the vehicles battery to "eliminate" corrosion. Any advice is appreciated.  thanks

ANSWER: Hey Joe. Don't do the black icky stuff thing, it really doesn't work. If you have it professionally undercoated, at someone like ziebart, be sure they use the paraffin based undercoat. It's more runny than sound deadener, and actually gets into the areas you want it to go- like into the seams. It's easily identified by it's beeswax-like color, it's not black. Hot oil treatments every year will work, but you can't miss a year, and the oil has to be new, clean oil- not used crankcase oil. I heard the electronic gadget is a scam, and doesn't really work- like those deer whistles. I think that 15 years out of a Caravan is pretty optimistic, I live here in the rust belt in NW Ohio. If you have it undercoated every few years, it might last that long, but undercoat won't stop rust going from the outside in. If the paint gets beat off the outer body, like around the wheels, rust is inevitable- these things must be properly fixed every time they show their ugly head. It also helps to keep the van garaged, and the salt washed off. That's probably tough to do in Canada without having a heated Garage, because the car will freeze shut if you wash it, and take it directly outside. Keep all these things in mind, and the van will look good a long time. Bill

---------- FOLLOW-UP ----------

QUESTION: Would you suggest Ziebart,Krown, or dealer applied rust inhibitor over the yearly oilsprays for better rust protection?  Of course everyplace says what "they" offer is best. What would you do William? Thanks for your unbiased opinion.

Answer
I wouldn't put undercoat over oil. I would find someone to do the paraffin based undercoat, and stick with that. I have more faith in it than oil, for the simple fact that most folks tend to neglect yearly oil treatments. It's also good for a longer period of time. It's thicker than oil nature will also give the underbody some protection from stones and such hitting the undercarriage where as oil will afford no such protection. I personally like oil after a rust repair, because you know that there is already some rust in the panels, and it will slow it's spread dramatically. You don't have that problem with a new vehicle- you want to prevent rust from starting. I have no real recommendation as far as a company, but I think i would stay away from the dealership. It sounds like they already tried to sell you some snake oil in the form of the electronic rust inhibitor. The kids on the undercoat rack won't do a good  job, either. Bill