Anything that holds moisture against exposed metal will accelerate rust. Add salt to that moisture and it speeds it way up.

 

no rust on my rockers, and it's very very humid here

my van's paint has decayed so badly that i've got entire sections down to bare metal and there's barely even surface rust going on

i 100% think it's road salt that's the issue for northern vans

 

I'm probably missing 30-50% of the paint on my roof, it's been peeling off to bare metal for 5 years now, and it has a very light layer of rust. I could scrub it off with paper towels.

 

I have to agree with Baron.

Take a look at the gen 4 vans from Seattle Washington or Vancouver Canada. Both cities get mega rain in the winter but only about three days of snow a year so very wet with virtually no salt on the roads.

The only vans that have rust are the ones that routinely go out of the city in the winter (say into the The Cascade Range) and don’t wash the salt off when back in the city.

Cascade Range - Wikipedia

seattle cars & trucks - craigslist

But I have to say Baron, here in the North Pacific you can’t have bare medal. Just too much rain and eventually you will get rust – you do need to at least primer if not paint. With primer your vehicle will not rust in the North Pacific region, even with the rain all fall and winter.

 

Corrosion occurs around foamed areas in the lower body panels. The foam traps moisture and hinders/prevents drainage. A salt air environment will speed the corrosion process up considerably.

For the rocker panels, more drain holes and a proven corrosion inhibitor like Fluid Film, Rust Check Inhibitor (red) or Krown (Rust Protection and Lubricant) , applied every year or two, through drain holes and drilled holes, slows down the process considerably. Some actually pour old transmission fluid directly into the rocker panels through drilled holes and at the sliding door track recess (holes already exist there for drainage from the track directly into the rocker panel ). That works.

Consider the rocker panels a drainage conduit that can stay wet, or damp, day after day.

Take a look at a Van that has been treated by Krown, and one will see the location of drilled holes based on their knowledge/experience/technical direction to the technicians. I mention Krown because it comes highly recommended and technicians are considered to be well trained. A local Krown Shop here has a guy that has been applying Krown for many years, does training of others, and has a great reputation. Application is 75% of the success.

As for spraying water underneath during winter, yes and no.

• what's in the water? more salt?
• under body corrosion during winter is hindered by cold weather anyway. Spring is the bad time.
• spraying underneath may remove salt but also remove some sprayed on corrosion protection
• a good rain storm does the same thing.
• spraying underneath increases water contact
• corrosion is mostly happening from inside out, how's an under body wash going to help that?
• under body corrosion is not a prime area of concern, especially if a vehicle has been corrosion protected.
• a priority would be to check the drain holes, sometimes they are blocked by seam sealant from the factory.
• the brine being used these days will negate any wash job in short order, applying a fresh coat to a clean surface .

Yep, the car wash guys will tell you to spray underneath and it may make you feel good. What it accomplishes is up for debate. Just sayin.

Fluid Film:Automotive | Fluid Film
Rust Check Rust Inhibitor: Rust Inhibitor – Rust Check | Cars | Vans | Trucks
Krown Rust Control: Krown Rust Control

 

A salt air environment will speed the corrosion process up considerably.

Sorry but I have to dispute that.

Take a look at the ocean cities in the USA. Now take a look at untreated gen-4 vans (any vehicle for that matter) in the coastal cities were they don’t salt the roads. Los Angeles one of the best places to get rust free classic cars because A-very dry B-no salt on roads but lots of salt in the air. Even coastal cities were it rains a lot Houston = 50 inches rain per year, but virtually no salt on roads one of the best places to get a rust free car.

As I said, two northern cities on the Pacific coast with lot’s of rain Seattle and Vancouver are pretty good bets to get rust free untreated vehicles.

Now take a look at the rust belt cities, even the ones away from the ocean (away from salt air environment) – well virtually any untreated vehicle will turn into a rust bucket in a few years due to the salt on the roads...

 

Our van remains mostly rust free here in humid, salty NJ. It looks SO much better than 90% of 18-year-old vehicles (especially other minivans). We have had people come up to us and offer CASH for our van.

Our strategies:

Run a dehumidifier in the garages in the summer

Rinse water on the undercarriage when washing in the winter

Seal the roof seams with flowable windshield sealant (I've done this twice over the years)

Small crack in the roof

I discovered this crack yesterday; it is in the roof just on top of the sliding door. I found it on both sides of the van and at the beginnings and the ends of the sliding doors. Any thoughts about this??

www.chryslerminivan.net

Use an undercoating spray on areas where road grit is kicked up. (being careful not to clog drain holes in the rockers)

 

Yep. Rust happens everywhere. 95% of the rusted cars I see are Northern, but I have seen a few that have rusted from sitting around and ones from coastal areas. Northern salt is by far the worst offender, with salty coastal air being 2nd worst.

 

Move to Chile, it has the driest desert on earth. I've heard of no rainfall in recorded history...

Atacama Desert - Wikipedia

en.m.wikipedia.org

 

Atamaca desert actually got rain in recent years, killed everything, I think.

How about where they park all the planes in Arizona, the Pinal Air Park?

 

I dump used ATF into the holes covered by the rubber plugs in the B and C pillars. I believe it goes down, sits on top of the foam in the pillars/dogleg area, seeps down between the foam and sheet metal. Also, remove rear speakers and you have access to the wheelhouse, dogleg and rear quarter panel areas. You can also dump ATF or similar into the sliding door tracks, place you van in a nose high orientation (on a hill) and watch the product drip out the pinch weld all along the rocker. Turn the van around on the hill and it drips out of the other section of rocker pinch weld. Buckets or eavestrough (Jeepman's idea) are good to catch what's dripping out. IMO, rust happens where water pools. Thin ATF of other rustproofing pools in the same places that water does and rust occurs, plus displaces water from folded seams and wicks upwards, protecting metal.

I had a 2006 DGC, live 60 feet from the ocean in Atlantic Canada and had no rust on my van, while all others around here were rotted out in the rear rocker and dogleg areas. Salt spray on our roads and highways - thrown up by other vehicles - soaks our vehicles and it seeps down past rubber window seals etc. Heat and cold cycles - IMO - cause inner panel condensation. Although it doesn't seem to be the case here, a lot of people just spray undercoating on the exterior of the chassis and don't know to spray it in interior panels where it really works. I do undercoat the chassis too with a thicker product.

I am going to experiment with biodegradable rustproofing. I picked up a jug of Canola oil and a liter of acetone. The ratio is 10:1 (oil to acetone). I'm doing this, not because I am an environmentalist, but because it's cheap and reportedly very effective. Of course, I'd rather have veggie oil on my driveway than petroleum-based stuff. I am also picking up some wax toilet rings and mineral spirits and will make my own wax/oil-based solution. I believe that a wax-based product is the only thing that stands a chance of not getting washed away in such areas as wheel wells, suspension components, exposed chassis areas etc.

 

I am going to experiment with biodegradable rustproofing. I picked up a jug of Canola oil and a liter of acetone. The ratio is 10:1 (oil to acetone). I'm doing this, not because I am an environmentalist, but because it's cheap and reportedly very effective. Of course, I'd rather have veggie oil on my driveway than petroleum-based stuff. I am also picking up some wax toilet rings and mineral spirits and will make my own wax/oil-based solution. I believe that a wax-based product is the only thing that stands a chance of not getting washed away in such areas as wheel wells, suspension components, exposed chassis areas etc.

I don't recommend any type of wax oil even it may stay on longer in the heavy splash zones. From the APA (Automobile Protection Association) site at Automobile Protection Association | Services - Rustproofing

Most dealers use a wax-based anti-rust spray. Wax is not a "self-healing" product. This means that when you have stones and rocks hit the underbody, they will actually chip away the wax. Also, over time the wax hardens and cracks and moisture will get trapped into these cracks and crevices, increasing the probability of corrosion.

As for canola oil, vegetable oil is a thinner for Fluid Film.

A competitor for Fluid Film these days is Woolwax, which is heavier, so they say.

Woolwax Auto Undercoat

Woolwax brand of lanolin/woolgrease automotive undercoating protection.

www.woolwax.ca

Fluid Film and Rust Check are "dripless" unless over-sprayed, so your driveway will be fine. Park your vehicle on the grass for a day, if worried. Fluid Film is also used in the food industry

FLUID FILM is FDA food grade approved in Canada, and FDA approved as non-hazardous in the U.S.A.

FLUID FILM® is Essential for Farm Equipment Maintenance
FLUID FILM® woolwax formulation is classified as non-toxic and non-hazardous and will not burn greenery when used on cutting devices. In harsh climates or conditions, FLUID FILM® will not freeze and retains a slick consistency, keeping chains and moving parts from binding or building up with dirt and debris. With a high flashpoint, exceptional water displacement and non-conductive characteristics, FLUID FILM® is the perfect protectant for battery terminals and electrical connections. FLUID FILM® also brings luster back to sun-baked coatings and helps prevent dirt and mud from caking on painted surfaces.

Don't forget the electrical connections in the engine bay, on the chassis and inside paneled areas. Fluid Film, a plenty, keeps my Jeep's engine bay protected from electrical problems.

 

Paraffin wax maybe, I think you could dissolve it in isopropyl alcohol, acetone, or some other solvent. I've seen it in a highly volatile solvent that rapidly evaporated, the product was used to coat high-end bicycle chains.

I've jokingly said that a leaky, grimy drivetrain is a built in antirust system on older vehicles...

 

I've jokingly said that a leaky, grimy drivetrain is a built in antirust system on older vehicles...

That's no joke, the more oily a vehicle is, the more protected it is from corrosion and electrical problems.

 

Rubberized undercoating? There must be an expanding foam that is effective inside cavities, something professional that is mixed as a two step.

 

I sealed a body seam leak on my mom's Taurus with plain old expanding foam in a can. Her floor would get drenched in all the FL rain storms because of a piss poor seal job on the seam below the windshield and above the dead pedal. Shot the foam in and made sure the part facing outside wouldn't be a pocket to hold water or debris. It's seen several storms over the months it's been on and no leaks. I think any expanding foam would work as long as the surface is relatively clean and as dry as possible.

 

Jeepman, I can see that 'rust' is a subject close to your heart. That said, do you feel the same about 'ferric oxide'?

 

Ferric oxide ....... is that the stuff that forms on aluminum hoods or are you talking about ferritic stainless steel (magnetic even)?

No, it's not just about corrosion of steel/metals, it's about electrical wires and connectors, hoses from drying out, lubrication, repelling moisture, discouraging animals from chewing away, etc.

Tip for today: If you are making up your own vehicle corrosion protection concoction, go light on the sugar.

 

The paint bond to the OE zinc?? treated surfaces of the rocker panels isn't the best either.