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Old 15th September 2015, 14:12   #1
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Electronic device for rust prevention?

Quite an unique product!

I stumbled upon this while browsing an Australian outback magazine. "Electronic Rust Prevention System". A bit of googling showed up a number of such products. Ebay Link.

Seems pretty popular in Australia and Canada, from what I have read, the concept is cool.

This is how they explain it

Quote:
To understand how the ERPS system works you first need to understand two underlying concepts:

1. What is rust? Rust is the normal electrochemical process of metals slowly returning to their natural, unrefined state. It occurs when iron and oxygen combine. Moisture and salt increase the rate of the chemical reaction.
2. Why does rust happen? Very simply stated, iron and oxygen have opposite charges so they seek each other out to combine. When they combine, the iron loses electrons to oxygen atoms. This is called oxidation and when it happens it produces a chemical reaction that causes rust.

So What Does ERPS Do?
Basically, the ERPS system interferes with the electrical charge between iron and oxygen so it becomes hard for them to combine to form rust. ERPS uses a proprietary electronic “capacitive coupler” system to continuously replace lost electrons from the iron in vehicles and metal structures to prevent or reduce the rusting process.

The process goes like this:
1. An Electron Generator – the ERPS Power Unit – transfers an output voltage to the ERPS electro-couplers.

2. The ERPS electro-couplers become charged and act as the positive plate of a capacitor. An electron rich, negative charge is created on the vehicle’s metal surface making it act as the negative plate. The paint acts as a dielectric, holding the charge static.

3. Rust is caused by the loss of electrons from iron when iron and oxygen combine, but because the capacitor works to constantly replace lost electrons on the vehicle’s body, rust is prevented.
For further reading, a different vendor >> CAT System

Chemistry wasn't one of my strong points in school or in college. But from what ever little I remember, this should work.

So, I went on to read user reviews. Found a bunch here. Its a 50:50 case, some claim wonders, others have had drained battery, rusting with in a year. etc etc.

Now, considering the age of the firm manufacturing it (ERPS), the product's 5 year warranty and vehicle corrosion warranty (AUS only), I have a feeling this system does work, at least delays rusting.

I liked this chaps comment... I have seen lot of bolero pickups rusted beyond help, being used by fishermen at the coast, especially in Kerala.

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If we move beyond automobiles, these systems should be able to prevent rust on outdoor units at sea side.
For that matter, a whole blooming big ship... or will this electronic attract the wrong ions from the sea water and turn the ship into something else?? About that, chemistry experts can comment... am out.
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Old 15th September 2015, 15:09   #2
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Re: Electronic device for rust prevention?

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Originally Posted by Spinnerr View Post
I liked this chaps comment... I have seen lot of bolero pickups rusted beyond help, being used by fishermen at the coast, especially in Kerala.

If we move beyond automobiles, these systems should be able to prevent rust on outdoor units at sea side.
It's a load of bull. I've used three such devices, the most recent car to wear one was my Jeep. Didn't work, and the body rusted nevertheless.

1. Nearly all modern cars are rust proof anyway. The way they are treated on the production line / paint shop is much evolved over yesteryears. As long as you take basic precautions, your modern car will never rust. My 10 year old C220, 8 year old City Vtec, 8 year old Civic & 4 year old Sunny had / have no major rust formation.

2. For older rust-prone cars, these devices don't work. If you own an old car, better to use coatings like Wurth. Worked wonders in my Jeep and I do live by the seaside.

This thread has some stellar advice on rust-proofing older cars.
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Old 15th September 2015, 16:51   #3
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The concept is nothing new though the way the website promotes it appears to be: So I am inclined to believe that it might be hokum.
But the concept is fine.

In the industry, we actually use cathodic protection to prevent rusting of civil structures, oil/gas pipelines etc. https://en.wikipedia.org/wiki/Cathodic_protection
In which case another metal (which is more reactive and has lesser electrode potential) is sacrificed (by becoming anode) to save iron from rusting.

I am sure everyone would've seen Galvanized Iron where we coat Zinc over Iron.
Zinc has lower electrode potential than Iron (http://www.physchem.co.za/data/electrode_potentials.htm) and therefore gets oxidized preferentially compared to iron.

Please note you don't need to coat the entire surface of iron. So as an example - you wish to protect the chassis - attach one piece of zinc to some place on the chassis. Since the body is not connected to the chassis, you will need to attach one more piece to the body.
Similarly the doors are isolated, so you would need another piece attached to the doors.

Oh by the way as an add-on and perhaps a correction to my post above - the problem with cathodic protection on cars is that since rusting is a localized phenomena (only where moisture collects) on iron and not simply because of presence of oxygen, the zinc pieces needs to be in contact with this moisture - thus making it unpractical for a car. {where all will you install the zinc pieces?}

Last edited by GTO : 16th September 2015 at 15:43. Reason: Merging back to back posts
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Old 16th September 2015, 10:30   #4
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Re: Electronic device for rust prevention?

You guys are right.

Further reading with "electronic rust proofing sham", "Does it work" search parameters did provide a lot of reasons why it would not work.

It explains why most "new" car easily survives the first five years without rust, how the product is banned in some US states for making tall claims and why what works on ships and boats wont work on car (incomplete circuit).

Australian LR forum
A science teachers take
Corrosion doctor

Do note, there are equal number of websites and people who claim the device has worked like magic. Don't get misguided.
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Old 16th September 2015, 13:45   #5
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Re: Electronic device for rust prevention?

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Originally Posted by alpha1 View Post
Oh by the way as an add-on and perhaps a correction to my post above - the problem with cathodic protection on cars is that since rusting is a localized phenomena (only where moisture collects) on iron and not simply because of presence of oxygen, the zinc pieces needs to be in contact with this moisture - thus making it unpractical for a car. {where all will you install the zinc pieces?}
That right. It works very well on ships hulls as they are emerged in water!
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Old 16th September 2015, 16:32   #6
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Re: Electronic device for rust prevention?

Vital on boats of all sizes. Hull fitting honeycombs and goes to powder. Water gushes in. Boat sinks.
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Old 16th September 2015, 19:07   #7
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Re: Electronic device for rust prevention?

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Vital on boats of all sizes. Hull fitting honeycombs and goes to powder. Water gushes in. Boat sinks.
Sometimes people think cathodic protection is to protect the (expensive) propellor, but its purely the hull. Or more specifically (as Alpha1) pointed out is the 'lesser' material that gets sacrificed. For instance if the hull fittings are made out of brass, you will have no problems with them, but if they are metal, they are susceptible to eroding, hence cathodic protection by welding anode (usually zinc or similar) onto the hull will work fine. (Oh, and don't paint over the anode!)

http://www.marineinsight.com/marine/...odes-on-ships/

I do rustproof all my classic cars with Dinitrol, but modern cars are much better protected to start with. Better materials, better surface treatment, better paint and better design (less water traps)

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Old 17th September 2015, 01:17   #8
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Re: Electronic device for rust prevention?

The kind of boats of which I have any experience are an order of magnitude smaller!

So, it was GRP, or occasionally, wood and most people had heard stories of through-hull fittings, eg the toilet outlet, that just crumbled away.

But, If I remember correctly, electricity was an important factor in that case. No electrics, no problem?
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Old 17th September 2015, 09:24   #9
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Re: Electronic device for rust prevention?

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Originally Posted by Thad E Ginathom View Post
. No electrics, no problem?
Not a hundred percent sure what you mean. There is a clear difference between corrosion caused by poor electricals (stray currents etc) and galvanic corrossion.

They have different causes and need to be adressed seperately. Both are an electical phenomena if that's what you mean.

http://www.mgduff.co.uk/leisure-craf...rotection.html

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Old 17th September 2015, 14:50   #10
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Re: Electronic device for rust prevention?

OK, yes... I had some confusion there.

Thanks.
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Old 21st September 2015, 20:25   #11
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Re: Electronic device for rust prevention?

My dad had one of these on our old Fiat Safari, a brand called "Rust Arrestor". suffice to say it did not work at all. He hoped to prevent rust as we live by the seaside but only regular repainting helped
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