Rust-salt crust removal

[73Coupe]

Removing rust from the body structure crevices where the body to stub mounts are. This area is semi-exposed and this became filled with road debris. Since the car lived its life in SASK and Alberta, I assume it was exposed to a few rounds of salt. Not much exposure, so no severe damage, but even just once is too much, in my opinion.

I'm trying to remove all of the rust and paint it. Been soaking in Evapo-Rust, Naval Jelly (Phosphoric acid), even HCL here and there but this crust is super tough. Acid doesn't seem to touch it. Evapo-rust is taking a lot longer than usual, and I've gone through a lot more solution that I normally would.

I'm guessing that the salt has mixed with the iron oxide to form some other type of oxide/salt coating

Attached photo is not the greatest but you can see the orange rust/salt crust.... Naval jelly didn't do anything to it. Usually it turns black as it converts rust.

I found another product called "Salts Gone" but not sure what that chemical is.

So wondering if anyone has run into this before...?

 

[Big_John]

Road salt will just wash out with water, so I'm not sure what you are seeing. There is times where any coating turns into a thick scale on it and I'm wondering if that is what you have.

Example is this rear axle housing. That has to be removed mechanically. Wire wheel or my favorite is a needle scaler followed by a wire wheel in an angle grinder. It could also be sand blasted, but that depends on location etc. Even with sand blasting, I've removed heavy scale first with the scaler and then blasted.

I coat everything with Ospho and that works best for me.

 

[300rag]

Removing rust from the body structure crevices where the body to stub mounts are. This area is semi-exposed and this became filled with road debris. Since the car lived its life in SASK and Alberta, I assume it was exposed to a few rounds of salt. Not much exposure, so no severe damage, but even just once is too much, in my opinion.

I'm trying to remove all of the rust and paint it. Been soaking in Evapo-Rust, Naval Jelly (Phosphoric acid), even HCL here and there but this crust is super tough. Acid doesn't seem to touch it. Evapo-rust is taking a lot longer than usual, and I've gone through a lot more solution that I normally would.

I'm guessing that the salt has mixed with the iron oxide to form some other type of oxide/salt coating

Attached photo is not the greatest but you can see the orange rust/salt crust.... Naval jelly didn't do anything to it. Usually it turns black as it converts rust.

I found another product called "Salts Gone" but not sure what that chemical is.

So wondering if anyone has run into this before...?

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Back in the day there wasn't a lot of salt used in AB/SASK. The winter temps were too cold. A lot of sand and gravel was used on the roads. When I moved out here in '79 I rarely had salt residue on my vehicles unless i went into the National parks. The feds used salt on their roads , but the province rarely did.

 

[73Coupe]

Back in the day there wasn't a lot of salt used in AB/SASK. The winter temps were too cold. A lot of sand and gravel was used on the roads. When I moved out here in '79 I rarely had salt residue on my vehicles unless i went into the National parks. The feds used salt on their roads , but the province rarely did.

Ah...! Well, there was a ton of sand and gravel in these body mount pockets and inside the stub frame. That 'splains it. Perhaps the minerals from the sand and other deposits from perhaps driving on unpaved roads mixed with the rust to form this tough coating.

As for the mechanical removal mentioned by @Big_John , I wish there was access but unfortunately these are the hidden areas and chemical means are the only option. Perhaps a sand blaster would work in some areas, but I don't have that capability in my garage.

 

[Darter6]

You may check around for a mobile crushed walnut blaster business. Had a friend in Pa that had a mobile business.
Retired when he hit 70.
Worked great on rust,paint what have you. Just a thought.