Undercoating/Rust Prevention

I think people make the mistake of washing their frame in the winter with a lanolin product. You WILL wash it off if you wash your underbody. Last year I applied fluid film and wool wax in the fall and it was still very present even last week when I applied my new coating.

 

Agreed. I applied fluid film the next day after i bought my truck. It has had the first coating when i got it in April '21. My logic was going into the Spring time, i will have more time to build up those layers. The more layers i put on, the better. Then I applied another one before winter in October '21.

Over the years there will be a thick coating of that, and it will protect my frame. i don't plan on washing my undercarriage at all. I am about to put on a third coating in the coming weeks. I haven't washed the underside of my truck at all and I am going to continue building up those layers of Fluid Film.

The only areas that washed off very minimally are near the wheel well where the tire spray is, and even then I touch that up when I see it needs to be done.

 

Yep, best way to do it. I've had my truck for a year and I keep the coverage on. Truck is over 7 years old. Frame still looks great. Few photos of as I was doing this year's treatment.

 

I never wash my trucks undercarriage in the winter, the roads will do it. We get slushy roads all winter long. Fluid flim works better on my mower deck.

 

Yep, not from my experience. Works fine.

 

Did you use Fluid film cans for application on your truck when it washed off, or an air compressor plus spray gun kit?

I bought a 26 gallon compressor from Lowes and a spray gun kit from eBay specifically for when I apply Fluid Film. It applies it thick and gets everywhere. Every time I apply it I used a gallon of the stuff, makeing sure everything is coated nice and thick. After a couple days when it creeps there is a nice glaze to it, kind of like a glazed donut.

The spray gun kit came with different attachment hoses so you can coat the inside of the frame and other high pressure nozzles where you can control how much and at what pressure it comes out.

Maybe you weren't using enough Fluid film and that's why you experienced it washing off? Or maybe fluid film cans don't apply as uniformly as a compressor + spray gun setup?

I'm trying to understand how your fluidl film washes away during winter and mine doesn't...

 

I'm genuinely curious as well because I only get wash out around the wheel wells. I lay it on thick as hell everywhere. I will apply surface shield and/or WoolWax to places where it comes into contact with water spray.

 

I live on the coast and often dunk the rear of my Taco in salt water while
launching and retrieving my bay boat. I always rinse the back and underneath
of the truck when I wash the boat. Now that I have a new 2021 I wonder about
what I could do to prevent salt water corrosion.

 

I'd recommend washing the ass end of the truck every time you do that with fresh water for a good 10 or 15 minutes. That's the only way you're gonna win. My dad bought a T100 about 15 years ago and the guy he got it from did the same thing. After a couple years my dad had to get a new rear axle because the salt water ate through it and made it leak.

 

this makes no sense. ^^^^^^^^


you are not going to 100% wash off a lanolin product with water spray alone. if you think you are, try this... get some lanolin lotion, apply some to both hands GENEROUSLY, then turn on a water source, and without rubbing, or any soap of any kind, try to get it ALL off. it is not going to happen.

over time, with salt, heavy spray etc... it may dry out but, as with the hand experiment, you will find there is still a residue. those dry areas should be re-coated/re-treated, periodically. preferably, prior to the first salt, snow event, the truck will see, in the fall. this way it is "protected" by build up, over the winter.

all spring, summer, and fall during rain driving, (if you do not wash, flush the under body), most or all of the previous winters salt will be washed away.

also, you state you applied fluid film and wool wax to your own vehicle, and it was still there. how? since you say it washes off... FF and WW are lanolin based.

Ski

 

The amount of fluid film on the chassis won't make any difference. There is no effective "layering" with it. Provided you have even coverage one "layer" will be as effective as 100.

Fluid film creeps so no need to do extra layering for scratches or chips. In areas of high washing (behind the wheels) just touch it up yearly.

If you are going to coat it yearly IMO you should in fact wash it. Fluid film holds dirt, which itself can hold some measure of water. Washing it off gets the dirt off. At the very least the mechanic won't hate you as much.

From what I am seeing wool wax is a better product. Same manufacture and nearly the same product, however it's thicker and resistant road washing a bit better.

 

"Using no soap". Soap at the carwash and high pressure spray will remove the product. I've done it myself. It may not be 100% removed but yes in some areas it is.

I don't think I agree that it doesn't matter how much you put on because more product means more creeping power. The more you put on the more it has a chance to creep and the more product means more product to creep. I agree that it does self heal but over time with road debris naturally removing it I'd want more than enough product to fill in the gaps.

Also, yes lanolin attracts some degree of dirt but I also don't believe it retains moisture as it naturally dispels it bringing it to the surface. Anything solid that is trapped within it is basically encapsulated until it eventually let's go in a mild wash or rain.

 

Idk, after every winter when i did my tundra with fluid flim, it was completely gone by april. Nothing but surface rust was left forming. You have no idea how bad the roads can get here when your traveling 50 miles every day back, and forth to work in slush, and on rainy days. Its like getting the undercarriage of your truck power washed.

 

Don't agree at all. Why would I spend the time to wash it off every year, just to then go ahead apply a fresh coat of Fluid Film?

The whole point of Fluid film is that it attracts road grime, dirt, and other nastiness. Over time this creates a barrier between the metal frame and the corrosive elements(salt, water, etc) that contains all this gross stuff. The oily barrier attracts dirt and yes, it is gross and sucks to work with, but that's what gloves are for. My experience is the same as sonofliberty92, i don't believe it retains moisture.

I was stating a fact that with each coat you put on, another so called oily 'barrier' gets put on top which attracts more dirt and road grime. And in turn, this thick multiple layer gross road grime is on the frame protecting it from corrosion. So I disagree wholeheartedly, that there is no so called "layering", and that the layers have no effect. When doing research before getting my truck I stumbled upon Repair geek on YouTube and dove deep on this topic, and in his videos he states that the benefit of Fluid Film is that overtime, with each coat it creates a thick coating of nasty sludge, dirt, road grime which protects that frame. After multiple years of coats, this will be thick and gross of course, but I'd rather have a nasty oily intact frame than one that is rusted out with holes in it.

 

The point of fluid film is an oily coating that keep oxygen and moisture from getting to the metal. Folks are thinking of the layer of grime as like a layer of undercoating. What is effective is not creating a layer of "paint" on the outside made of something sticky and dirt. What is effective is a microscopic thick layer of oil that separates the oxygen from the metal.

You don't oil a rifle to create a layer of dirt to encompass it, you oil it so that moisture and air cannot come in contact with the metal.

 

The way i had it figured with very limited success using fluid flim, i had to get a bigger gun. It was called Rp-342 cosmoline.

 

Applied two cans as much as I could just from sliding under the truck, this stuff smells god awful.

 

2 cans? I used 4 for just the hood, tailgate, and 4 doors. then another 3 quarts of a gallon can, on the underside with the pro applicator gun, my first year application. every year after 2 cans for touch up to the aforementioned panels, and 1/2 gallon on the rest . it is your investment, spray it like you dont want to pay another 40k for another vehicle due to rust, ever... or you may be one of those disappointed in the result of your application, and choice of protectant. Ski

 

Krown yearly for me. Every October. My fathers 2012 Tacoma that’s been Krowned every year is more than enough proof for me that it works.

I even do touch ups with a spray can of the stuff throughout the winter. I also spray more in the engine bay as they are too puss to spray much in there. And when I get it sprayed, I say “lay it on thick, I don’t care about my driveway having drips” as the marks are gone by spring anyway.

A word of warning for people using Krown:
The kids they hire to apply the product are not always very mechanically inclined. Every year they remove the taillights to spray down the bed sides. It’s part of their procedure for trucks. Every. Single. One. Of the mounting tabs on my taillights was shattered from the dudes rapping the lights back on with a fucking impact. Both my taillights literally fell off while driving and were just hanging by the wires flopping in the breeze. This happened months after my last spray. Between all that, my Krown became under new management at some point so it’s been interesting trying to explain to them that they owe me 700 bucks. They are the only people besides myself who have turned bolts on my truck (and of course they fucked up)

a good example of why I hate others working on my vehicle for even the simplest things.

The mounting tabs are just thin plastic with a speed nut clip on them. Hand tight only.

I’m between a rock and a hard place, as this is the only rustproofer we have and the product is decent.

I got stories. I’ve experienced more automotive service related horror stories than anyone I know, and I’ve only been driving for like 12 years. I’m talking entire rear axles falling off vehicles type hackery.

anyway TLDR, ask Krown not to touch your taillights. I’m not the only one this has happened to.

 

2 cans will not cut it. My tacoma took 6 cans of cosmoline just to coat the outside of the undercarriage. Don't forget to do the insides of the frame sections that are boxed in, and the insides of the rockers.