Low Rust Taco - brush or not? paint or not? Fluid Film or not?

Colorado uses very little salt compared to Iowa, Minnesota, Wisconsin. The MgCl2 has anti corrosion additives. I know because I ran tox tests on the stuff and I could not figure out what the chemicals were. Parts of Colorado are near desert, parts are fairly wet. We always have a low RH even those spots that see high annual rain/snow fall from orthographic precip.
Not as hard on cars as the midwest. not at all.

I have no clue what you are talking about. But if you are testing products on rusty parts i am all ears.

I would use a pressure washer also.

 

Cadmus,

Just picked up a 2003 DC 4x4. CO and CA car. My rust situation looks almost exactly like yours. Pretty good with maybe some heavier spots around the leaf spring mounts.

I do not want to spend a lot of time on this. I am not going to take the bed off, I am not going to get it sand blasted. I am not going to look up its colon to see if it has its poop in a group.
As far as I know unless I sell it it will live in CO the rest of its life.

Hope you can answer these questions

Would you say that Chassis Saver is the easiest way to go about dealing with the rust?
Am I correct in that you just do a little wire brushing to get the flake off then just put on the CS?
Can it be sprayed?
Easiest cheapest way to spray?
Can you just hit everything under the truck or do you need to watch out for wires, etc.?
How much do you think to do the whole under body?

Preemptive thanks from one FoCo Taco owner to another.

 

Based on what you said, the most effective route would be fluid film. It is very easy to apply, cheap, and actually works pretty damn well. The only down side is having to apply it 1-2 times a year to keep it fully coated at all times.
To me I see the fact that it’s not permanent as an advantage because if any bad rust spots form you can easily see it, where covering it with a rust preventative paint will hide the rust for the most part and only kill the surface rust. That’s just based on my experience, using correseal works but it will eventually start rusting again, where because fluid film is like an oil it almost leeches into the metal and “soaks in”.
I went all out and removed my bed and ground off all rust and used a heavy duty clear coat meant for bare metal just to make any rust spots visible in the future, but if you want quick and easy and cheap, get fluid film. And the gallon will last a couple years depending on how often you coat it.

That being said, everyone has a different experience. In Colorado where it snows, and depending how often you off-road through water it will wash off quicker than normal. But if it’s just a daily driver and rarely see much water crossings and no salt road, I’d say it’s a good option. I do live in Florida where I don’t have to deal with snow, just the salt air near the coast, which does make shit rust but not even close to the way it does up north

 

I have seen lots of people recommend FF, but please correct me if I am wrong, but it doesn't stop or convert rust right? Isn't it more of a preventative measure. So unless you have gotten rid of all the rust beforehand it will just keep spreading? Or does it seal off the O2 and H20 to prevent anymore spreading?

I liked this video. Real world testing.

https://m.roadkillcustoms.com/rust-encapsulator-paints/

 

The top rear shock mounts that are welded into the frame are a place that rust lives and there is poor
drainage in these spots.

You have to drop your spare tire to get up close to inspect this area on the passenger side in particular

 

It DOES stop rust, and can prevent it.
I have tested this with old sheet metal With a decent bit of surface rust and very minor pitting, put FF on half and left it outside, it got rained on as well. the side With FF just turned the metal blackish gray and stopped the rust while the non FF side got worse as it was left outside.
The water did wash some of the fluid film off but it still didn’t rust

 

It will not kill or convert rust, but it will stop it right in it's tracks as it will seal it from moistuire and air. It will also prevent and/or prevent it from coming back. But first, you have ro remove as much loose flaking rust as possible to be able to reach as much of the frame (or steel piece) as possible

So yes, it's more of a preventative measure

NEVER use a product that dries and hardens on after application as undercoating. Moisture will eventually get behind it though cracks or chips, accelerating the corrosion process as it gets trapped between the frame and the undercoating product

The best option is oil-based undercoatings, like Fluid Film, Krown and similar products. But these are good only if you apply them on a YEARLY basis. But their consistency is both their strenght and flaw. They have water-like consistency and will creep anywere, into the smallest crevice and corner BUT this consistency will also allow them to get washed off on areas exposed to elements. This is why you must apply it yearly

 

So are you saying to not use something like Chassis Saver or Eastwood?

Does Fluid Film turn the rust black at all? Call it vanity but if I am spending the time under my truck I want it to look good again as well. Having everything nice and black again would be nice.

 

Corroseal turns rust to black magnetite
Can be painted over or Fluid filmed.

 

No, paint is fine, as long as you remove or treat the rust before applying. Painting directly over surface rust is okay, but more than that, you need to remove or neutralize the rust
What I meant to avoid is stuff like rubberized undercoating, spray-on liner, gravelguard/rockguard.

And no, Fluid Film won't turn the rust black. It's straw colored and stinks, but oh boy it works. Rust converters will turn it black/deep brown and can be painted over

If the truck is exposed to salt or any other corrosive agent, paint only is not enough to protect, as the salt will eat through it. That's why you must apply FF on top, but as I said earlier, you must apply it yearly as it tends to get washed off

 

So would this be a good route or redundant?

Lightly wire brush the rust. I am only worried about areas around leaf mounts.

Then Chassis Saver or Eastwood

Then Fluid Film?

 

@yourrealdad

I have had a good experience with Chassis Saver. But never used FF or the Eastwood version. My experience on this topic is that every one recommends what they use even if they have no experience with other products. It is also complicated by different climates, different truck use, different truck storage practices, truck hygiene practices, different climate. I guess you and I have spatial autocorrelation in our favor.

I found rustolium to be short lived. Sanding then priming then painting was hard work (on non-tacos BTW) and the rust was only held off a short time. I found rustolium's rust reformer to be useless. Any rubber bed coating is not long lived below the car in my experience and it will not bond to loose rust.
Painting over FF is not an option (says users and an installer) so look to the future and think about your plans.

Chassis saver worked well for me. I brushed it on, not spray. But you could spray if you have the equipment. It does not damage electrical. It appears to not harm joints and bolts and the manufacturer suggests that to be true. Chassis saver LIKES to stick to rust. That fact relieves a good deal of stress in prep work. I really am happy with Cha$$i$ $aver even if expensive and even if it is tenaciously sticky when you get it on your skin, clothes, or tools. Kinda surprised how strong it is.

I am fighting to get work done before the weather gets too hot. I will try to read all these posts later and respond more articulately then.

 

Yes.Wirebrush, treat with rust killer/converter, paint then fluid film
And don't forget to FF the inside of the frame as well. Use this 360 wand if you use cans:
https://www.ebay.com/itm/FLUID-FILM-360-EXTENSION-WAND-for-spray-cans-FREE-SHIPPING/172860435043

You are worried about the area around the leaf springs? why? Is it rusted through? The only way to find out is to take a hammer to it and see if it will punch a hole.
Where is your truck from? Has it seen winter salt and chemicals?

 

Because painting over fluid film is not an option, i am doing just this. Except I do not plan to use fluid film until I near the end of the life of the truck (like in many years) or until I feel I need to protect the inner voids of the sheet metal (so far I do not) or until I find Chassis saver is not able to keep up with new rust (not the case yet).

 

Do I need to paint? Isn't that what CS is a converter and paint in one?

Can I just FF inside the frame or is there a way to get CS in it as well?

Leaf springs, mounts, bolts are all very rusty, but I believe it is surface rust.

Car is a CA/CO truck

 

Chassis Saver is a paint. Very good paint. You can paint over it. Or paint more on. You can wash it and it does not attract dirt.
But you can not try something else later if you use FF. FF stays sticky and attracts dirt.

I will be trying to Chassis Saver inside the box frame this fall. Lots of people spray it in there, i do not own spray equipment (I have done everything with disposable Harbor Freight Brushes).

My bolts and leaf springs also had significant surface rust when i got the truck. I just Chassis Saver over them after a good wash. No prob.

 

Chassis Saver is not a rust converter, it is a thick metal paint.

FF should be the last step as you can't paint or apply any kind of treatment over it

Do you need to paint? If you did sand/wirebrush to bare metal, yes
If it's just surface rust you have, you don't even have to wirebrush it. Just spray some fluid film and be done with it.
Though if you want to paint it anyway, you can paint directly over surface rust no problem. Except for loose flaking rust

By the way, do you have pictures of what worries you so much about your frame? It will help us to give you the best answer

 

@Cadmus, thanks for posting this thread. I too have been debating a similar situation. I have a truck with a year old replacement frame. Only protection is the oem flat black “finish”. I want to do everything in my power to protect and preserve the frame.

I have settled on hand painting the frame this summer with Chassis Saver (or Eastwood) followed by a FF treatment in the fall. I figure now is the best time to establish an extra layer of painted protection before Fluid Film enters the picture.

That said, I may have cheated the start with some Rustoleum enamel paint. I recently started on a headlight replacement project that quickly snowballed. I decided to paint all of the the forward facing metalwork for added protection prior to reassembling the front end. I don’t know how much good it will do, but figured something was better than nothing.

This is a picture of the second coat of Rustoleum I did this afternoon.

 

Wow. So clean!!!!!

 

Thank you! But, looks are deceiving. I spent a LOT of time cleaning it. I started with washing out all of the dried mud that I foolishly stuffed up there by, you guessed it, running through mud on purpose.

After the mud was rinsed away I degreased it, washed it, scuffed with Scotch bright, washed it again, rubbed it down with Acetone, then finally, paint.

I felt crazy and it was a lot of effort, but they say painting is all about the prep. I took it to heart. Hopefully, the effort was/is worth it.