Rust Prevention/Conversion Experience

I recently bought my 91 4runner that has some minor surface rust all throughout the chassis.

Im in Oregon so not in the rust belt but still curious on your guys' recommendations and experiences with treating this kind of rust and what your steps of treatment would be. First step obviously attacking it with a wire wheel to remove as much rust and corrosion as possible

Any tips/experiences and advice on what works best would be much appreciated. upload some pics if you got ‘em!

 

I'm in New Hampshire and rotting away as we speak.
The best recipe I have found for fixing heavy rust on my frame and components is to first spend alot of time needle scaling all the loose rust and rot spots. Then using a wire wheel on my 4" angle grinder to clean up everything even more.
After that, I took care to weld in a few patches over some holey spots and also reinforce where the lower arms connect to the frame.

I spayed on a wet coat of Ospho treatment and after 24hrs a second coat.
Then brushed on rustoleum rusty metal primer and rustoleum black.
I'm letting it cure up real good over the summer before I soak it all in fluidfilm.
It's alot of work. Wear a mask, earmuffs,and goggles and I spent about 2 weeks doing mine.

 

I’ll add that if you’re going with fluid film, woolwax, or any of the other oil coatings - do it yourself.

It’s a huge pain in the ass, it’s messy, and you might need to buy an air compressor. But from my experience, it ends up with a better result. Just dedicate a weekend to do it and take your time.

I say this after doing it 3 times. First time I did it myself, and told myself never again, I rather pay a pro to do it in a few hours. Second time I paid a pro, and noticed later he missed a lot of spots. I ended up doing it myself the 3rd time going over the entire underside again.

I’m sure some places are better than others, but I had a new 4Runner and really wanted it done right the first time.

 

I made 4 car ramps out of trees with my chainsaw. Gets the tires up about 16 inches from the ground and a respirator and goggles.
Fluid film the crap out of it every year.
I even spray it inside the drain holes on all 4 doors and inside the fender gaps, in some spots in the engine bay.
Lastly I have to clean the hell out of my spare tire rim that collects all sorts of filth spray paint it and fluid film that too

 

In my experience budget 8-10 hours over a weekend:

1. Needle gun, wire wheel, hand chisel, wire brush everything. Any combination of those will be good. Really spend the time to go over areas with lots of scaling. One member here gave me some good advice; Don't go too crazy on this step, it will almost never be perfect and that's okay. Anything during this stage is better than nothing.

2. Spray down the frame (Including inside the frame rails and cross members) with water at minimum. I purchased a product called salt gone, but I'm sure any soap and water combo would work fine.

3. Coat frame in a oil based coating. I use Fluid Film, lots of people recommend Wool Wax but truthfully any oil based spray will work. No need to buy a compressor/spray gun, just prepare to buy 10-12 cans off the shelf. IMPORTANT spend the $10 and buy a 360 degree wand that attaches to the cans and allows you to spray inside the frame rails and cross members.

4. Drive down some gravel roads to start developing a layer over the oil coating.

 

welcome

 

Thank you all so much for the feedback! it’s really appreciated.

Some say to add a layer of rust preventing/converting paint (POR-15, Rustoleum) before spraying on the oil based coating (wool wax, Fluid film). what’s your guys opinion on this? does it prolong the life of the coating and lengthen the lifespan between needing coats? Some also say without doing so the rubbery coatings can just trap moisture and make rust worse in the future.

Feedback and experience appreciated!

 

I, personally, would not and have not done anything like rustoleum, POR15, etc. Fluid film, applied and then reapplied after some time, seems to be the best way to keep rust at bay. Ive seen way to much rust behind paint and sealers to ever trust them.

Clean the frame with water, let it dry, then buy a kit to apply the lanolin based treatment of your choice. I would stick with untinted, as the colorant screams hiding damage. I used Warehouse 9000, and really like the value. I went with fluid film kit, to include spray gun and both extension wands.

https://warehouse9000.com/

YMMV

 

My only thought with POR-15/Rustoleum is you need to have the base metal cleaned almost perfect before application. That's not realistic on the underbody of a 34 year old 4-Runner.

Fluid film black leaves a nice finish and after driving some time creates a good layer of "crud" that acts as another layer of defense.

 

Does it end up leaving a “crud” looking layer? how’s does it pose against a pressure washer for cleaning after wheeling trips and such?

 

Even fresh sprayed on oil based coating holds up well to cleaning. Do a test if you have some time on a piece of sheet metal, it'll leave a oily coating even after the pressure washer passes over multiple times. Obviously holding a pressure washer 2" from the frame in one sport for a prolonged period of time will strip almost anything away. It's designed to be applied once a year and survive the harsh winters of salt, sand and spray up.

In my experience the "crud" layer of dust, sand and dirt will aid in protecting the underside from washing

 

I discovered Ospho decades ago when I was cruising and maintaing sailboats. All the engine& trans components are steel/iron and rust is constant. Ospho is remarkable the way it affect the rust but not paint coatings on sound metal. I use it all the time around my house and vehicles.
It is acidic so use protection for face & skin.

 

I have never used por15 or ruber undercoating cause of fear of trapping moisture underneath.
I have used for many years Rustoleum rust converter that turns a rusty surface to a black primer type of surface and topcoat with paint.
But I found that it dosent work that well. After a few years gone by the rust comes back.

My last few attempts at killing rust once and for all has been using Ospho.
And wow what a difference. This stuff is the ticket for sure.
Go watch a few videos of using Ospho over rust and give ot a try.
Ospho then rusty metal primer then paint.
That's what I'm sticking with here on out.

Check out my before and after.

 

Beautiful feedback everyone thank you so much!

Contemplating fully pulling the trigger and combining all of these recommendations. attacking wish a wire brush, needle scaler, etc, treating with Ospho, using the rusty metal primer, light coat of paint, then a thick coat of some Fluid Film to protect it all? no salt on the roads here so i feel like that should last a good amount of time and add some good protection. what do we think?

 

All that's left is to do it!