Undercoating for rust prevention?

[RC Fan]

Hello!

What is the forum consensus on undercoating for rust prevention for those who get lots of snow? We will probably have our ‘18 Expedition for 8 years hopefully, and we would like to protect it from road salt.

Thanks in advance for your assistance!

 

[JExpedition07]

That’s always a good idea as even though your body panels are aluminum all structural and most drivetrain components are steel. I’m not sure if aluminum corrosion can be stopped with oil based products like on steel. Krown is pretty good at this and spray inside everything but it will drip for a day or so after.

 

[RC Fan]

Thanks for your reply!

I can live with the dripping, so no worries there.

 

[NASCAR Mike]

I would do the Krown oil. In my experience rubberized undercoating will block drainage holes and allow water to accumulate and then rust.

Having lived in Syracuse NY for years I know how bad the snow and all the salt they use can be on a vehicle. I would think Canada is the same.

Here in VA where we don't get much snow, I rinse the underside of my Expy with hot water when I pull into my garage.

 

[lbv150]

Fluid Film annually. Very effective in rust prevention. Many DOT and municipalities use it on their vehicles. Dealerships offer the service as well as independent shops. We have the capabilities to self spray it and buy in 5 gallon pails.

 

[poppie]

The IDIOTS at the Wisconsin DOT are partnering up with some of the county's to use BRINE in place of road salt crystals on state roads, salt crystals have to dissolve to start eating your RIDE while BRINE will start to eat the moment you get it on your ride not having to dissolve 1'st AND besides that what about the rebar in concrete road's along with all the bridge decking rebar, that concrete DOES get hair line crack's over time allowing that BRINE to soak down to eat the rebar = MORE POT HOLES and then there's the beam's supporting the bridge knowing that they are thick but never the less WHY, then there's the stream's , River's ,Lake's and private drinking water well's , I'm no liberal tree hugger but this is total INSANITY .

 

[NASCAR Mike]

Brine is only effective in pretreating before a snow storm. It is sprayed on the roads before it starts snowing. It prevents the snow from sticking to the surface. Once it snows localities use a sand / salt mixture. Granted the liquid brine will eventually kick up onto your car.

Every November I wash and wax all of my cars to help prevent snow/salt/sand/brine damage to my vehicles. As I mentioned before, when I drive home after being in the snow I wash down the entire car with warm water. Top to bottom, wheel wells and under chassis. I get the warm water from my sink in my garage. I get out the portable electric leaf blower and blow it dry. Takes me about 20 minutes total.

 

[99WhiteC5Coupe]

Brine is only effective in pretreating before a snow storm. It is sprayed on the roads before it starts snowing. It prevents the snow from sticking to the surface. Once it snows localities use a sand / salt mixture. Granted the liquid brine will eventually kick up onto your car.

Every November I wash and wax all of my cars to help prevent snow/salt/sand/brine damage to my vehicles. As I mentioned before, when I drive home after being in the snow I wash down the entire car with warm water. Top to bottom, wheel wells and under chassis. I get the warm water from my sink in my garage. I get out the portable electric leaf blower and blow it dry. Takes me about 20 minutes total.

The road crews in my state also use brine - and a sand mixture. The sand blasts away the paint and windshield glass, when it blows behind a vehicle, and also blasts off the anti-corrosion coating of parts under the vehicle. The sand clogs storm sewers and culvert pipes. When the snow melts, the sand lowers the coefficient of friction of the roadway and extends stoppping distances.

 

[Black]

The have been using brine here for at least 5 years and vehicles corrode so much faster since.

I would like to do Krown but closest place is 5 hours away and nothing cool around to make the annual drive worth it.

I’m going to get the Fluid Film DIY kit for $150 which should do both vehicles and just buy a new gallon each year.

Vehicles also get a heavy wax late fall.

Some of my iron parts like the rear diff and axles already have surface rust so I am going to paint them with some rust encapsulater to keep it from rusting and look better.

 

[Gordonzoo]

I too asked this same question on the Lincoln Nav forum and got similar responses. That forum does not have as many visitors so I thought I would hang out on the sister forum I too do not have a Krown service close by. I've put Wax-Oil on my 2018 Wrangler and 2016 Ram. It's a one and done application but some here are worried it may clog up drain lines. It's not rubber, its more like a hard wax or Tar. Is it just the AC drain line that I should be concerned about or are there others? I do like how the black looks underneath with Wax-Oil and it does not have to be applied again. You are supposed to go yearly for the panels but I'm more worried about the carriage. I lost my 1997 Ram and 2004.5 F-150. May they rust in piece. I'll not loose another.

 

[RC Fan]

I’d really like to use Fluid Film. Unfortunately, we don’t have anyone who applies it here.

I’d really like to get the kit and do it myself! Realistically how hard is it? I’ve watched several of the videos—seems doable to me.

 

[lbv150]

I’d really like to use Fluid Film. Unfortunately, we don’t have anyone who applies it here.

I’d really like to get the kit and do it myself! Realistically how hard is it? I’ve watched several of the videos—seems doable to me.

Do you have an air compressor? With the kit it is easy. Napa Auto parts sells the kit and the film in 1 or 5 gallon pails or buy online from others. Another alternative is to rattle can it with Fluid Film, Lowes and others sell it. With the kit I only use the long extension wand for all exposed underbody areas...better control. I drill holes in the doors and use the wand that sprays in a circle at the tip. Unfortunately the only thing that would make it super easy for me is a lift...I presently do all mine on the ground or jack stands.

 

[RC Fan]

Do you have an air compressor? With the kit it is easy. Napa Auto parts sells the kit and the film in 1 or 5 gallon pails or buy online from others. Another alternative is to rattle can it with Fluid Film, Lowes and others sell it. With the kit I only use the long extension wand for all exposed underbody areas...better control. I drill holes in the doors and use the wand that sprays in a circle at the tip. Unfortunately the only thing that would make it super easy for me is a lift...I presently do all mine on the ground or jack stands.

I do have access to a compressor and ramps.

It seems the Achilles Heel of undercoating is the poor application done by auto shops. I am really OCD when it comes to car care, so I feel like I would take my time and do a thorough job.

 

[JExpedition07]

Fluid film or an oil based coating is the way to go. Attracts dirt and debris to the coating and helps keep moisture and oxidation away.

 

[Black]

I’d really like to use Fluid Film. Unfortunately, we don’t have anyone who applies it here.

I’d really like to get the kit and do it myself! Realistically how hard is it? I’ve watched several of the videos—seems doable to me.

You are in Canada you likely have a Krown applicator near you.

https://www.krown.com/en/

Essentially the same idea as Fluid Film

 

[Motorcity muscle]

Best thing you can do is wash the vehicle the next day of being out in the snow and salt. Best not to park in a heated garage till its cleaned up.

 

[Jigstick]

Is Fluid Film safe for the factory coating on the 2018 Expy frames? My 2018 has 1500miles on it, and Im wanting to get Krown or FF on it. But I don't want either to eat off the factory frame coating.

 

[scottdm]

They also spray brine on the roads in my area, and I'm just religious about washing the vehicle and using a carwash that sprays from the bottom, and I also manually spray down my engine bay to get the salt off. As a guy that enjoys working on my vehicle, I can't imagine how nasty it would be to have oily/tar like undercoating sprayed on everything if you're trying to work under the vehicle. Also curious if the places that apply the coating remove all the underbody skid plates/shields prior to applying the product. Many of the skid plates/shields have drain holes for all water to drain which would need to be maintained to avoid water pooling on top of the skid plates/shields.

 

[Adieu]

Why not just spray a rattle can bedliner product?

 

[lbv150]

You guys don't understand what Fluid Film is. Bedliner product or any paint or hard coating does not stop rust. It dries and moisture gets behind it and then the rust starts. FF does not hurt paint, in fact some use it as a polish. FF is not messy after a few days. It stops rust from starting and stops rust from spreading like once the Expy rockers start. You have to apply it annually and I check coverage every 3K oil change and touch it up if necessary. I spray the brake calipers, driveshafts, rear diff, tranny, anything underneath that looks like rust is starting. Nothing else works on preventing rust forming from road treatments. You still need to rinse off the salt but only use cold water as hot will remove the FF.