Electrolyse-like technology to protect cars from rust.

[ElectroNewby]

Have you heard of it ? Anyone experienced it so far ?
Here, the winters are harse... and if a bit of paint is lifted, rust may appear fast (I had typed fat).

Just like electrolyse is used to remove rust from metal, they made a process to protect cars with a battery (I beleive that exists for boats, although I'm not sure if it's a chemical). anyway... it's like 400$

* as I was looking for a website to show you what I'm talking about, I just found an old thread heh https://www.electro-tech-online.com/threads/electronic-rust-protection-for-cars.13859/

Now I'm not asking for how it's made and how to build one, those systems are already there ready to be bought. Just want your opinion/experience. Is it worth it the very first year (we just got a brand new car).

Should that even protect small parts like screws and stuff ?

 

[Ross Craney]

That is why they changed from +ve earth to -ve earth on cars

 

[rfs100]

RustStop Electronic rust protection and rust prevention.
Electronic Rust Inhibitor - dslreports.com

There are a million postings splattered all across the web, half of which say this works, the other half says otherwise. I doubt that the responses on this forum will be any different. One point that was made is that modern cars have such extensive rust protection, that such devices are not necessary. The concensious seems to be that these units are expensive add-ons , like undercoating, that are almost pure profit to dealers.
Almost all sea going vessels use a cathode system to keep the hulls rust free, but unlike ships hulls that are all continuous sheets of metal, with no gaps, supposidly the same type of unit will not work because cars have too many gaps in there body, even though the entire body is a continuous ground. One posting suggested that such units would only work if a car was completely submerged in salt water.

I doubt that this posting will dredge up any new info, other than what was sated in the original old thread, or is stated in the numerous threads spread across the internet.


A really good quote:

>Hi, I'm looking for a schematic to construct a anti rust device, to be
>fitted to a 12v car. Can anyone help?

I think they only work well with boats where the metal parts are
always in contact with the water. The idea is simple and only takes
an op amp and perhaps driver transistor. You measure the voltage
being produced by the galvanic action of dissimilar metals and apply
enough current to another electrode to cancel the galvanic voltage.

Unless all the parts are bonded - connected together electrically - it
won't work. Unless the electrode and parts being protected aren't wet
at the same time by the same electrolyte, it won't work.

If it were that easy - you could just bolt a sacrificial anode (zinc)
to the car and be done with it - that technique has worked well for
many years in boats.

Things to search for are "active cathodic protection"

I knew a guy with a boat who was paying the dockmaster to look after
it. He complained that the zincs, he added, where being eaten away in
no time - and plating out on the bronze parts below the water line.
So I went out to look at it - it had an active rust prevention scheme
already in place. That suggests, to me, that had he had galvanized
fittings below the water line they might be eaten away leaving the
iron exposed - but I don't know for a fact. I just told him to use
one system or the other, but not both.

 

[Boncuk]

Audi uses electrolytic zinc coating of the entire car body, doors, hood and trunk cover.

I saw a car body at the Ingolstadt plant having been placed outdoors for 10 years with no sign of rust.

Audi also guarantees for five years of rust free cars.

Boncuk

 

[audioguru]

Audi also guarantees for five years of rust free cars.

I think Audi and Volkswagen are the same company.
My '75 VW Rabbit rusted away in 3 years. I bought a "genuine" German Blaupunk AM/FM/recording cassette radio for it and ordered its service manual. The manual had the Chinese manufacturer's name blacked out with a felt-tipped pen. I souped-up the cassette recording circuit so it was truly hi-fi.

 

[BrownOut]

So was it just a pile of rust with a still functioning "genuine" Blaupunk unit sticking in it?

 

[audioguru]

My '75VW Rabbit was not used for a couple of years because I got a company car.
When I advertised it for sale, three German guys came and caused an auction with the price rising. I sold it to the highest bidder then went away on a holiday.

When I returned from my holiday there was a notice in my mail that the VW Rabbit was found abandoned on a street and got a parking fine. If I kept the ownership that I gave to the German guy then I could have sold it again and maybe again and again.

The mechanism of the Chinese "Blaupunkt" cassette recorder/player in the radio was also worn out. If it was made in Germany then it would still be working perfectly today.

Grundig was another excellent radio manufacturer. When they were nearly bankrupt they were bought by a bunch of Turkish odd people.

 

[rfs100]

Audi uses electrolytic zinc coating of the entire car body, doors, hood and trunk cover.

I saw a car body at the Ingolstadt plant having been placed outdoors for 10 years with no sign of rust.

Audi also guarantees for five years of rust free cars.

Boncuk

Too bad their warrantee doesnt live up to reality. The Audi forumns are filled with people complaining about premaure rusting. Here is a good example:

Here's their loophole: (from the warranty manual) 'Surface Corrosion without
perforation' is not covered. So if the panel doesn't rust through they don't have
to cover it. But wait, there's more: 'does not cover perforation resulting from
the failure to promptly repair.... surface corrosion'. Big loophole. If there's
a little rust, it's your problem, if that becomes big rust, it's your fault.

 

[Boncuk]

I think Audi and Volkswagen are the same company.
My '75 VW Rabbit rusted away in 3 years. I bought a "genuine" German Blaupunk AM/FM/recording cassette radio for it and ordered its service manual. The manual had the Chinese manufacturer's name blacked out with a felt-tipped pen. I souped-up the cassette recording circuit so it was truly hi-fi.

Hi audioguru,

It's correct. Audi and VW are the same company. Mr. Piech was director of Audi Ingolstadt until he took over VW management at Wolfsburg. Before he took over VW did not use electrolytic zinc on their car bodies.

Regards

Hans

 

[Nigel Goodwin]

Grundig was another excellent radio manufacturer. When they were nearly bankrupt they were bought by a bunch of Turkish odd people.

Not quite correct - Grundig went entirely bankrupt, Beko (Turkish) and Alba (British? - but only really a name) bought the rights to the name afterwards. Alba sold their share of the Grundig name to Beko last year, but maintianed the right to use the name in the UK for a specific period (only a year or two). So the Grundig name is now 100% owned by Beko, and is just used on the usual cheap rubbish.

We used to be a major Grundig dealer - it's sadly missed

 

[tytower]

Just back to the Original posters question
Ive said before I have a 1948 Landrover Series 1 still in use by me on my farm. It is positive earth. It had little rust until about 2001 when I decided to put an alternator on it and to do so I had to change the polarity to Negative earth.

In the next two years rust started eating the underbody and steel parts dramatically. I changed back , cleaned up what rust I could and hope I´ve got it stabilised. Time will tell

Any dissimilar metals will produce a battery effect and one will be the anode and one the cathode . One will get slowly eaten away . The only way I know to stop it is to disconnect them .

Now a system to equalise the voltages sounds like it might work if it can be kept accurate all the time for long periods of time - like years. If something goes wrong you could increase the degradation 10 fold pretty easily I would imagine.

On my boat I have a Ferralight hull which is similar to Ferro cement without the cement. It has a polyester putty filler through the hull and fibreglass coating both sides. The steel in the hull is high tensile rods of 5 and 7 mm going both ways each 2 inches max. So that has 7 layers of heavy square mesh tied over it ,3 inside and 4 out.

So there is a lot of steel in the hull.

This is joined at various places to a thick copper strap running the length of the boat and that is connected to 4 sacrificial anodes outside the hull. The anodes eat out in about 10 years and wherever I check there is no rust on the hull steel which is mostly encased. I can only check the steel where I remove some to install things like extra depth sounders. except for the prop and rudder shaft which is stainless.

Now I do not connect anything else to this system . The motor , steering & prop shafts up to a rubber insulators/shock absorber and all other items are separately earthed back to the negative battery terminal.

This works but I would not dare inject any currents as you suggest above unless I was absolutely sure it was reliable. The corrosion is caused by stray currents . Whenever you turn on your radio the current goes somewhere. Usually to earth on the battery and when you turn it off the capacitors continue to discharge electrons through to earth.

If this earth is the car or boat body then corrosion can take place !