Phosphoric acid -v- rust

[260DET]

Have been told that phosphoric acid can be used to permanently treat rust in cavities and other inaccessible places. Dilute it, spray it in, allow to dry. Then spray in techtyl or whatever final proprietary coating you are going to use. The acid neutralises the rust, the final coating protects it from future deterioration.

 

No experience myself, no idea how much the acid should be diluted. Comments, experiences?

[turbo_fb]

I have tryed with some rust remover that contains a little bit phos. acid. It smells terribly and turns the rust white. It's a long time since I used it so I cant remember how it went with the rust, but I think it only covers the surface of the rust.

Best would be to grind away most of the rust then use the phos. acid to treat any pores or something.

[y-not]

Muriatic acid eats the heck out of rust. Nasty fumes, wear a good mask and gloves. Problem is as soon as you rinse off the acid the steel will flash rust in minutes. But for the buck ($3.00 Gal. at the hardware store) you can't beat it. I use a plastic flower window box to soak old tools and small parts.

Bill

[DaleMX]

I think that most anti-rust product pre treatments (like por 15) use electroless tin as a barrier metal that locks out O2.

[AK-Z]

Actually, I bought some stuff from walmart that does the job quite well. Its "rust remover; jelly rust remover" by klean strip (spelled correctly). I just bought it to see how well it would work.

 

I was entirely surprised. With in 5 min the surface rust was gone, then in 10-20, most of the deeper rust was visibally reduced. I wish I had a camera so I can show you guys.

 

It says that it contains phosphoric acid and alcohol, so I assume that it can be mixed with water, but haven't tried it and it seems to work better when generously applied.

[JMortensen]

Why not just use a rust converting primer like Zero-Rust or POR15 or Rust Bullet?

[AK-Z]

Powder coating and just something to mess around with are my reasons.

 

Plus I rather be doublely sure that the parts aren't going to rust. I rather wait than spend time sanding/grinding/blasting heavy rust.

[Clifton]

I used Rust Mort. You can get it at auto body shops. It does contain acid.

[2003z]

on steel, I use muriatic acid, followed up by a bath in this iron phosphate. It says to soak for two minutes and rinse, but I find it works better to soak and blow dry with compressed air. http://www.columbiacoatings.com/1024t45676ty78yj789345erfrg5467.htm

[JMortensen]

2003z, all I see when I look at that web page is flashing thingies. What are we looking for?

[2003z]

I thought that might happen. Sometimes it only goes to their home page.

Select:

Online store,

Pre-treatment,

Iron Phosphate

[AK-Z]

Hmmm. interesting. I might want to try that iron phosphate. thanx

[Brad-ManQ45]

There are rust removers, converters and coatings that lock to the rust and prevent O2 from getting to the metal the rust is on.

 

The later category was developed during WWII.

 

Removers, such as navel jelly have to be rinsed and then quickly coated with something- the problem being in enclosed areas, getting to it.

 

Ospho and PickleX - are converters - they actually combine with the rust ant turn them into something that can't rust.

 

When welding, I alsways coat my steel with ospho before welding - it takes care of any rust, and falls in the converter category.

 

If I had my car on a rotisserie and wanter to do say - the voids in windshield and cowl, I would use Ospho, dumping it in and then rolling the car around a few times (sealing all outlets of course), then try and spray something like Zero Rust into those voids as best I could.

 

I will be taking my own advice in my own project '75. The reason for using ospho is that it is much cheaper than PickleX and to insure a good coatingI'll have to use a bit of it to slosh around in there.