frame rust

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As mentioned before, I have two spots on my F250 where the frame is rusted pretty bad. While the rust is bad, it still drives fine and is in no danger of breaking in half or anything like that anytime soon. I was considering 3 options, which would be the best? I'll be pulling the fuel tank down soon to do the 7.3 Hutch mod to the fuel tank, so I'll have complete access to the drivers side rust also. I was thinking of spraying down the rusted areas with either Fluid film OR used diesel oil cut down with diesel so it wouldnt be too thick, with a potato pump every 2 months or so, or I was considering grinding off the flaking rust and coating it good with POR 15. which would be thee best solution?
 
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I would probably do both. Clean and rust protect (POR15 or something like it) the areas you can get to, then when you're all done, spray it all with Fluid film or the like, in both areas you painted, and everywhere else you didn't paint.
 
If there is an issue of weakened steel that needs to be repaired.

POR15 or Eastwood Rust Encapsulator require prep to the metal area in order for it to work. That is sometimes easy and sometimes not.

Fluid Film or CarWell will seep through the rust and protect against future rust. Just clean off any large rust flakes or dirt first.
 
How big??? Quarter size? Dollar bill size? Bigger?

At minimum, Id likely try to grind off any major, loose rust, then etch properly with ospho or one of the other converters, then paint.

POR can be good stuff, but its all about how good of a bond it has, and how moisture can creep under. Im not convinced that its always the best solution.

If its too big, Id probably want to consider welding extra metal to the frame, not sure how much benefit it would have, but Id assume some...

Id do appropriate spraying with Krown, FF, or a waxy coating, depending upon how moisture can access the frame in those areas.
 
I Fluid Filmed an older Toyota Tacoma with the Kellesport pro gun specifically designed for Fluid Film. I paid about $120 for the gun and nozzles and the entire job took only a few hours. The great advantage of the Kellesport gun is the 36 inch flex nozzle. I was able to snake the nozzle into every frame hole, pull the trigger and pull it out slowly. The gun left a super heavy coat of fluid film INSIDE the box frame. This may be less critical in a truck with a C channel frame. Fluid Film can be applied over existing rust with no surface prep, just spray yearly if you live in a road salt area. Quick, easy, cheap ( $45 per gallon ) Sorry if I sound like a salesman for fluid Film, the stuff flat out works.

But wait, there's more!

Once you have the pro spray gun, you can rust proof vehicles for extra cash. One gallon will do 2 vehicles.
 
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CarWell gives you a warranty if their shop does your car when new and then yearly.

The shop has experience as to where to drill holes for the body cavities.
 
Wire wheel on an angle grinder (not a cup brush on a drill) and acid or sandblast and acid. Sandblasting + acid is the only method to stop the rust from coming back ever short of immersion according to my research. When I wanted to remove rust on my car, I sandblasted it with a handheld blaster with a hopper, applied ospho and then painted it.

Ospho is pretty expensive, so you could wire wheel it and hit it with pickling vinegar or some type of acid from a building supply store.

I think the acid is the key, as it converts available rust into something else I forget the name of. It turns the rust from red to black. I think sulfuric acid is the active ingredient in most "rust converters". Acid also etches surrounding steel to improve paint adhesion.

If you get most of the rust and do a good job painting, you will probably never have to worry again. If you caught it early enough.

EDIT: "bad" frame rust should really be cut out and patched, having rusty quarters or fenders will not cause your car to bend in half like a rusty frame could.
 
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I used Coro- seal. You could grind off the rust the best you can.Brush the Coro-seal on. Looks great.
 
Originally Posted By: maxdustington
I think the acid is the key, as it converts available rust into something else I forget the name of. It turns the rust from red to black. I think sulfuric acid is the active ingredient in most "rust converters". Acid also etches surrounding steel to improve paint adhesion.

I'm pretty sure what you want is phosphoric acid (not sulphuric acid). I expect it converts rust (iron oxide) into iron phosphate.

There are good and cheap phosphoric acid products. As I recall Naval Jelly is one. It's all nasty stuff so you need gloves, goggles, long sleeves and a good supply of water to dip/drench yourself as necessary.

When you grind out rust there are always little pits of rust left. You have to "neutralize" the rust in those pits or it just reappears, initially as dots of rust through your paint. I treated a rust patch on an older Buick with surface grinding, then application after application of phosphoric acid and then just painted it. The rust never reappeared. A friend took a Mercedes 300D with an almost identical patch of rust to a reputable body shop. It looked great initially but within 6 months or so the rusty dots were coming back through the paint. He was disgusted.

Nowadays I'd use POR-15 after the phosphoric acid treatment, then paint.

But I'm not an expert on any of this so feel free to correct and add.
 
Originally Posted By: ecotourist
Originally Posted By: maxdustington
I think the acid is the key, as it converts available rust into something else I forget the name of. It turns the rust from red to black. I think sulfuric acid is the active ingredient in most "rust converters". Acid also etches surrounding steel to improve paint adhesion.

I'm pretty sure what you want is phosphoric acid (not sulphuric acid). I expect it converts rust (iron oxide) into iron phosphate.

There are good and cheap phosphoric acid products. As I recall Naval Jelly is one. It's all nasty stuff so you need gloves, goggles, long sleeves and a good supply of water to dip/drench yourself as necessary.

When you grind out rust there are always little pits of rust left. You have to "neutralize" the rust in those pits or it just reappears, initially as dots of rust through your paint. I treated a rust patch on an older Buick with surface grinding, then application after application of phosphoric acid and then just painted it. The rust never reappeared. A friend took a Mercedes 300D with an almost identical patch of rust to a reputable body shop. It looked great initially but within 6 months or so the rusty dots were coming back through the paint. He was disgusted.

Nowadays I'd use POR-15 after the phosphoric acid treatment, then paint.

But I'm not an expert on any of this so feel free to correct and add.


You nailed it, buddy. Rust gets into the pores of the metal that wire wheeling and even sandblasting leave behind.

I'm not a pro at all but I have researched a ton as I think I live in the rust belt? I love cars and rust are both of our main enemies. Ospho is phosphoric acid, I checked the label. Same stuff that is in delicious Coca-Cola.
 
Originally Posted By: maxdustington
I'm not a pro at all but I have researched a ton as I think I live in the rust belt? I love cars and rust are both of our main enemies. Ospho is phosphoric acid, I checked the label. Same stuff that is in delicious Coca-Cola.

I'm pretty sure it's actually Carbonic acid (CO2 + H20) in Coca Cola. Phosphoric acid would do really really really bad things to your stomach. Drinking a very small amount might be fatal - and a horrible death too.

When the Carbonic acid in Coca Cola breaks down, you get CO2 and water. The CO2 gives you bubbles, and burps.
 
get good Gloves and a bunch of Dollar store sponges with the green scrubbie attached, and a square of Naplins/ paper towels.

Apply and scrub and clean the steel with the scrubbie sponge saturated in Ospho. Brown rust will turn blackl, bare steel turns grey, painted surfaces get etched rust under paint will lift the paint above, but good paint is not removed, but it will change color slightly

Once the rust turns black, one can take a sharpish chisel they no longer care about and remove the black, and rescrub with the sponge. The rust spots will eventually turn to pitted steel if the process is repeated. One can speed up the brown to black conversion with a hairdrier.

Or one can paint over the black Iron phosphate instead of trying to remove it to get more Rust vcconverted and removed as much as they want until they are left with rust free bare etched steel.

The Ospho really preps the surface well for adhesion, when applied with the scrubbie, scrubbed and wiped off, with fresh applied and allowed some time to etch and convert. Scrubbing with Ospho is strangely cathartic.

I tried scrubbing with Naval Jelly, and was disappointed.
 
Originally Posted By: ecotourist
Originally Posted By: maxdustington
I'm not a pro at all but I have researched a ton as I think I live in the rust belt? I love cars and rust are both of our main enemies. Ospho is phosphoric acid, I checked the label. Same stuff that is in delicious Coca-Cola.

I'm pretty sure it's actually Carbonic acid (CO2 + H20) in Coca Cola. Phosphoric acid would do really really really bad things to your stomach. Drinking a very small amount might be fatal - and a horrible death too.

When the Carbonic acid in Coca Cola breaks down, you get CO2 and water. The CO2 gives you bubbles, and burps.

In case I wasn't absolutely clear about it, I'm pretty sure there is no phosphoric acid in Coca Cola or any other beverage.
 
I use sunflower oil mixed with motor oil as a cavity spray. I wouldnt personally use used motor oil because it is carcinogenic/teratogenic and it will contain acids, though it'll probably still work.

Fluid film may be better, dunno.

For surface treatment of rusty metal I use a flattened beer can as a grinding disk, with sunflower oil as a binder after initial rust removal. Seems to work quite well.

https://bobistheoilguy.com/forums/ubbthreads.php/topics/3864753/Coke_Can_for_Brake_Drums#Post3864753
 
It really surprises me, the more I read these stories, that rust proofing shops are not more readily available in the U.S.
I have mentioned it in other forums, for those that are looking to start their own business, that, imo, these would be great businesses/franchises to get into as I am sure the demand would be overwhelming.
http://www.rustcheck.ca/
https://www.krown.com/

These are practically the same undercoatings. A previous inventor/business partner of Rust Check broke away and started his own franchise.
The biggest issue is who is actually applying the product and how good of a job they do. I have used both because of that. My Rust Check guy sold his business to Midas so I now go to Krown as the next rust check guy I used, didn't do a good enough job imo.
My wife's car cost $135 and my truck $175 annually. Like someone once said, where can you get a body job/paint done for that.
 
Originally Posted By: wrcsixeight
Coca cola ingredients:

Ingredients: Carbonated Water, Sugar, Colour (Caramel E150d), Phosphoric Acid, Natural Flavourings Including Caffeine.

http://www.coca-cola.ie/drinks/coca-cola/coca-cola

Wow, you're right. It's hard to believe but it seems to be true. It must be pretty dilute.

That may explain why Coca Cola has those reputed corrosive and metal restoration effects. Never tried it myself (except of course with Rum and ice).
 
Originally Posted By: Ducked
I use sunflower oil mixed with motor oil as a cavity spray. I wouldnt personally use used motor oil because it is carcinogenic/teratogenic and it will contain acids, though it'll probably still work.

Fluid film may be better, dunno.

For surface treatment of rusty metal I use a flattened beer can as a grinding disk, with sunflower oil as a binder after initial rust removal. Seems to work quite well.

https://bobistheoilguy.com/forums/ubbthreads.php/topics/3864753/Coke_Can_for_Brake_Drums#Post3864753
When we cleaned out the family homestead, I snagged a 1/2 gallon jug of linseed oil. Linseed oil dries to an airtight coat. Away from the elements. it is great for coating interior voids to prevent condensation leading to rust through. It works well enough on framework and framework repairs on the Rat to to make it worthwhile. The cons to linseed oil is that it takes forever to dry. After I used a knotted wire wheel in a grinder to remove the scaled, I brushed on a 1st coat of thinned oil. From then on, the last step of every repair session was to add another coat . I stopped after 5 or 6 coats
 
Weapon of choice for the United State Navy. I spent a lot of time with working with them.

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