Thread: Rust prevention

I am not very familiar with Discos, but I believe that only the external body panels are alloy, with all the body framing being steel and hence subject to rust, and because it is usually thinner metal than the chassis it is more of a concern.

I don't recognise the term erps, but if it is an impressed current system, you can expect it to only work while the vehicle is totally submerged.

The key to preventing rust is to keep all surfaces coated with an impermeable film (usually paint), and to remove accumulations of mud and especially salt or salty mus as soon as possible. And preferably live inland of the Great Divide.

I believe by erps, TonyM is referring to Electronic Rust Prevention System...

Am I correct TonyM?

Originally posted by Grizzly_Adams
I believe by erps, TonyM is referring to Electronic Rust Prevention System...

Am I correct TonyM?

Hi guys, thanks for the replies. Yes Grizzly_Adams that's what I'm talking about! (sorry I'm a bad one for using acronyms all the time - laziness showing through) [img]style_emoticons/<#EMO_DIR#>/laugh.gif[/img]

JD - thanks for the tips, although I'm afraid living that far away from the water is a non-option for me, I have salt water in my blood and wouldn't last long that far away from the ocean, besides there's fish in that water! :roll:

Re your comment that erps will only work if the body is totally submerged, could you please expand on that? I don't understand, a lot of people around here use them and swear by them. Is this because of the alloy panels on the disco ???

You have to understand how galvanic protection works.
If you have a metal immersed in an electrolyte (a solution with ions in it) it will corrode by the atoms in the metal acquiring a positive charge and dissolving in the electrolyte. (how rapidly it does this depends on the metal mainly). Now if we apply a voltage to the metal so that it becomes negatively charged relative to the electrolyte, atoms of the metal will not pass into solution. This voltage can be applied either by a current source or by setting up a primary cell using a different metal which is lower in the electrochemical series (see for example http://www.corrosion-doctors.org/Aircraft/...eri-compat.htm) and ensuring that it is both electrically connected to the metal you want to protect and is in the same body of electrolyte. (If the voltage or the metal types is reversed, the corrosion is accelerated)

For the under water parts of ships and other marine structures this method (either way) is very effective, but it is of little if any use for the above water part of these or for any other structure not immersed in water (as the owner of a steel boat I know all about it!) The problem is that as soon as the electrolyte is not in a contiuous body, the protection becomes ineffective, as the local body of electrolyte - which may for example be a single spot of damp mud, simply assumes the same overall potential as the metal it is resting on, and the galvanic protection is totally irrelevant. The one exception to this is where a lower metal is spread over the metal you want to be protected with the gaps smaller than the smallest isolated drop of electrolyte. This is called galvanising, and is very effective. But use of anodes or impressed current in motor vehicles is just about pure snake oil - it probably has some slight benefit while you are actually driving through the surf, but for most users this is not when almost all the corrosion happens.

If these methods are unable to protect the above water part of ships and boats, why should you expect them to protect motor vehicles? It has nothing to do with the alloy body panels.
(I think Igot the polarities right, but the story is the same even if I did get it backwards)

Further reference :-
http://www.corrosion-doctors.org/Car/car-e...-protection.htm

The previous owner of my Defender fitted EPRS, I not sure that its as good as they advertise, I have a little bit of rust in the front foot wells, there has already been a repair job in the same area.

When EPRS is fitted the owner is supposed to present the car to an agent every 12 or 24 months for it to be check or warranty is voided.

I'm undicided if I will leave it on the vehical as I don't think I'm getting any benifit from it.

ERPS uses Capacitive Coupling.

Impressed Current / Cathodic Systems / Galvanic Anode are the ones ineffective in free air.

Don’t think that all electronic systems are the same or that “one size fits all”.

you can tell within weeks if erps isnt working as your paint continues to oxidize. when it is working correctly your paint gets no oxide on it ...

the local pro fisherman swear by erps and lanolin.

even landrover recommend the electronic version these days...

http://www.erps.com.au/

Originally posted by weeds
The previous owner of my Defender fitted EPRS, I not sure that its as good as they advertise, I have a little bit of rust in the front foot wells, there has already been a repair job in the same area.
.

how many red couplers are on it?

there is a blue box, and then there should be at least 3 or preferably 4 red couplers in different places on the truck on a defender.