Lets talk undercoating

Lets say you have the misfortune of living in the rust belt and are planning on buying a new vehicle you want to keep for 15 years.

Would you apply aftermarket undercoating to it? I don't mean the stuff at the dealer, I'm talking Ziebart, Krown or one of the DIY methods like fluid film.

I know the OEMs are doing a better job but I still see enough 5-7 year old trucks being advertised with "typical (insert brand) rust" that I think I should do something to help prolong the inevitable. On my current 2006 truck we thoroughly pressure washed the bottom 4 times a year in addition to regular trips to the car wash. I still had more rust than I wanted.

I've heard very good things about Waxoyle (SP?). I would try to recreate what I used to do at the dealership. We had a long tube that had a tip that would spray a 360* pattern and drag that through the frame, plus the usual spraying waxy stuff all over the place.

Remember that undercoating and rustproofing are two different things. I think if anything, undercoating (i.e. a rubberized or tar coating on the bottom of the car) can promote rust - as it ages and cracks, moisture can get in between it and the sheet metal. On the other hand, rustproofing like Waxoyl protects the sheet metal inside the cavities where the rust normally starts.

I think it's all a crap shoot. We had a new Pontiac that started rusting heavily after the fourth winter of ownership. Our Trailblazer is doing well after 12 years but I notice the frame is getting rusty.

Waxoyl, Eureka Fluid Film, or just using a paint brush and covering the whole undercarriage with used motor oil are all effective at preventing corrosion - provided you get good coverage everywhere. However they also need to be repeated annually(or even a couple times per winter), because they're not a permanent coating.

My truck gets Fluid Film every fall. It's too early to tell, but I have high hopes that it will keep the rust at bay for at least a while.

logdog wrote: Lets say you have the misfortune of living in the rust belt and are planning on buying a new vehicle you want to keep for 15 years. Would you apply aftermarket undercoating to it?

Absolutely not. Undercoating applied after-the-fact only seems to wick moisture and make rust happen faster.

Buy a German car that was galvanized. That, and/or buy a car at the bottom of its depreciation curve every fall to use as a sacrifical vehicle, and put the new car into storage. I have plenty of customers who do this. You could sell it in the spring and recoup the price of the vehicle. Planned well, you could use the same winter tire/wheels as the previous car.

BTW, anybody wanna buy a Volvo S40 in April?

Knurled Buy a German car

Nope. Never again. Ive owned several VWs and spent time as an Audi tech.

Besides, the Germans dont make 1 ton trucks and that is what Im buying.

Huh, a large percentage of what I work on is Audis (nobody else around here wants to touch 'em) and I love 'em. The only thing that seems to rust out on B5s are the rear upper control arm/shock mounts, pull them off and the body is still pristine underneath. You can fix electrical problems, you can fix anything but rust. Rust you just throw the car away. (And Audis are super easy to work on compared to 99% of other new cars)

The big problem I see with trucks is that they rust in ways that you can't really prevent. The body on frame construction leaves LOTS of little nooks and crannies that you can't protect but dirt and moisture find their way into. And then they flex a bunch, grinding that grit through the paint, and pretty soon your F350 doesn't have cab mounts anymore, or your Ram 3500's bed laterals are just plain gone.

Problem is: In most cases the rust occurs in places that the "ant rusts" don't reach. I find that going to the car wash with the underbody wash. Or drive through puddles, works very well.

The logical thing to do is to buy a German car and move south, right? That's what you were asking for help with right?

Parking in a garage every night is the best thing you can do. Hardly any rust on my 02 Accord that was garaged every night and driven during winters.

My fathers minivan was parked outside during the winter for a couple years and the rust exploded. Before that it was in a garage every night and hardly any rust.

stuart in mn wrote: Remember that undercoating and rustproofing are two different things. I think if anything, undercoating (i.e. a rubberized or tar coating on the bottom of the car) can promote rust - as it ages and cracks, moisture can get in between it and the sheet metal. On the other hand, rustproofing like Waxoyl protects the sheet metal inside the cavities where the rust normally starts.

In my head I have always lumped them in the same category but after digging around a bit today it looks like I should focus on "rust proofing".

petegossett wrote: Waxoyl, Eureka Fluid Film, or just using a paint brush and covering the whole undercarriage with used motor oil are all effective at preventing corrosion - provided you get good coverage everywhere. However they also need to be repeated annually(or even a couple times per winter), because they're not a permanent coating.

Prep work seems to be the key for any of the choices. That is sort of what worries me about having somebody do it for me. I have trust issues

It actually makes sense to me that it should be applied annually rather than just once.

Tom_Spangler wrote: My truck gets Fluid Film every fall. It's too early to tell, but I have high hopes that it will keep the rust at bay for at least a while.

How many years have you been doing it? I am leaning towards the Fluid Film right now.

fritzsch wrote: Parking in a garage every night is the best thing you can do.

Unfortunately my garage is not big enough for a crew cab/long bed. Of course its nothing a new garage wouldn't fix!

logdog wrote:

Tom_Spangler wrote: My truck gets Fluid Film every fall. It's too early to tell, but I have high hopes that it will keep the rust at bay for at least a while.

How many years have you been doing it? I am leaning towards the Fluid Film right now.

I just did it for the third time a couple of months ago. I get under there and spray everything I can see, and inside the rocker panels and such. I also use the aerosol cans of Fluid Film to get inside my doors. I remove a little rubber plug, insert the long flexible hose, and spray it inside the doors. I do the same thing with the tailgate. There's quite a bit of galvanized steel in the body, so I'm hoping with this (and storing it in a garage), I'll be able to keep it rust-free for a good long time. I plan on keeping this truck.

I haven't tried Waxoyl or any of the others. Nice thing about FF is that you can get it easily at Amazon and such. I got a kit 3 years ago with a gallon of the stuff and a spray gun (essentially a crude paint sprayer you use with compressed air). I've only now almost finished the gallon, and I've done the truck 3 times and the Taurus once. I've been through a few aerosol cans, of course.

Just made some of my own the other day.

2 wax toilet rings (carnauba wax), 1qt. non-detergent oil, 1gal. mineral spirits, 2 gal. Garden sprayer.

I heated up the wax in a clean coffee can. Dump the oil in with the wax and heat on a grill.

Once the wax melts, let it cool a little, dump it in the sprayer with the spirits, and spray away. You might want to keep it outside for a day as the spirits flash off.

We'll see how good it works in the spring. I had about 2/5 left after spraying the 87 4Runner.

We used a mix of used motor oil and kerosene in a garden sprayer when I lived in the rust belt. Drilled holes to hit the insides of inaccessable but still metal areas. However, all our stuff was already rustybut it did seem to slow it down.

Ain't the new full-size fords aluminum?

I had our 2012 Explorer treated with Corrosion Free. To soon to know if it will make a difference.

Dusterbd13 wrote: Ain't the new full-size fords aluminum?

Steel frame, lots of steel in the suspension, steel firewall. Kinda like a certain old British 4x4 with a strong propensity for corrosion.

This!

iadr wrote: Parking in a heated garage is the very worst thing you can do- condensation forms everywhere, including inside body channels, every time you drive in from the cold.

A heated garage, yes. But a regular non-heated garage is a good thing. The less time the vehicle spends exposed to the elements, the better. I bought my FIL's old F-150 from him when it was 8 years old. It was parked outside next to the house the whole time he owned it. The side that faced the house was pretty much rust-free. The other side had significant rust.