Rust Remover or Rust Converter?

[Ian21401]

I need to deal with several rust bubbles around the wheel arch rims on my 1992 940. Having done this on various cars I have owned over the years I’ve used various products to treat the area after removing loose paint and scale. On almost every occasion the rust eventually reappeared, sometimes sooner than I expected. I’ve checked out the adverts for various products which all profess to be the ultimate answer. But they would, wouldn’t they? I’ve watched numerous YouTube videos which each seem to advocate a different method and/or product.
Has anyone found an answer which lasts long enough to justify the time and effort spent?

[Volvofreak2]

Hej,

I do the treatment as follows: first I clean everything and remove loose rost. Then put Fertan Rostconverter on it an let it work a few days. Weather should be warm or you got a heated garage. Optimum airtemperature is about 20°C. Then clean it properly with water and it is recommendet not to remove the black converted stuff, this is building a protekting coat! Second step zincspray. Third step epoxyundercoat. This stuff is super because it is watertight! Now you can use filler and all other things to paint it.
This should stay rostfree now for a longer period of time, I do not say for ever!

Hej Gernot

[Ian21401]

Thanks Hej. That’s basically the method I’ve used in the past with various products and varying results.
One school of thought is not to use a converter under the zinc primer as it prevents the zinc from working as it should on the bare steel. Another states that the zinc is wasted when on the converter but works as it should on the surrounding bare steel.
I’m tempted to try that “Rust Doctor” stuff which I’ve never used before. It’s supposed to convert the rusty steel to magnetite (not a phosphate like other rust killers) which when dry has a latex surface which can be overpainted with just about anything, but I haven’t found a supplier yet.

[Volvofreak2]

Originally Posted by Ian21401

Thanks Hej. That’s basically the method I’ve used in the past with various products and varying results.
One school of thought is not to use a converter under the zinc primer as it prevents the zinc from working as it should on the bare steel. Another states that the zinc is wasted when on the converter but works as it should on the surrounding bare steel.
I’m tempted to try that “Rust Doctor” stuff which I’ve never used before. It’s supposed to convert the rusty steel to magnetite (not a phosphate like other rust killers) which when dry has a latex surface which can be overpainted with just about anything, but I haven’t found a supplier yet.

Hej,

well, the best converter I know, is Fertan. I am not sure if, and under what brandname, this is sold in uk. But the more important thing is the epoxyundercoat. Since I use that, I got impressive better results! I is coating the whole troublezone an as it is watertight, nothing kann get to the steel, that makes it rust!

Hej Gernot

[Austin160]

As I see it, wheel arch rust is usually through-rust, and starts from the inner surface of the panel. No amount of treatment to the surface of the rust on the outside face, is going to effect any degree of permanent ‘cure’.
Treating the outer surface simply results in some degree of delay, and it usually ends up where the rust on the inside continues to push through into the outer surface.
For what it’s worth, for outer- face originating rust, I have used Vatcan (I think it is called?) to good effect.

[Volvofreak2]

Originally Posted by Austin160

As I see it, wheel arch rust is usually through-rust, and starts from the inner surface of the panel. No amount of treatment to the surface of the rust on the outside face, is going to effect any degree of permanent ‘cure’.
Treating the outer surface simply results in some degree of delay, and it usually ends up where the rust on the inside continues to push through into the outer surface.
For what it’s worth, for outer- face originating rust, I have used Vatcan (I think it is called?) to good effect.

Well, ok, this is of course an argument. I just explained what I do with rostproblems in general. But if it´s rost-through, well then only helps cut out the spot an wheld a new surface!

Hej Gernot

[green van man]

The only long term cure for rust I've found is a grinder and mig welder. All else may buy you a year or 2 but is in no way permanent.

The trick to beating rust is to not let it start, once it's bubbling through its showing prehaps a tenth of what's there.
Many years of welding rusty cars has shown me that an effective job needs access to both sides of the panel, cut into good metal, rebuild from there and then do a decent job of sealing the seam, painting and rust proofing both faces of the panel, all else is stop gap measures.

Paul.

[m0bzy]

over many cars I have fought the tin-worm with Waxoil, when the rust appears,paint on a dose of waxoil then leave it until you cannot stand the sight of it any longer, wipe off with white spirit then soap and water then prime etc ,when dry put some waxoil in a garden spray and give the inside face a good soaking,thinning down with white spirit helps get into seams and into places only liquids can get.

[green van man]

Originally Posted by m0bzy

over many cars I have fought the tin-worm with Waxoil, when the rust appears,paint on a dose of waxoil then leave it until you cannot stand the sight of it any longer, wipe off with white spirit then soap and water then prime etc ,when dry put some waxoil in a garden spray and give the inside face a good soaking,thinning down with white spirit helps get into seams and into places only liquids can get.

I find Dinitrol far superior to waxoil.
My experiance of wax oil is that despite its advertising blurb it does not stop rust and readily catches fire when the inevitable welding is done. Box sections sprayed with Waxoil internally spread the fire very quickly, as I have found to my cost.

Many garages will not weld a car that has been so treated because of the fire risk, those that will add a surcharge for fire watching in my experiance.

Paul.

[m0bzy]

green van man,you may well be right,as I have only been using it since my first Jaguar some 45 years ago.I bow to your superior knowledge.