Using a Sacrificial anode on a car to suppress or at least help prevent rusting

I have had a thought occur to me and i could use confirmation that I
am or i'm not nuts.
First off i live up in snow country and salt country, Ottawa Ontario
Canada
we put enough salt on our roads up here to make the ocean seem fit to
drink. And well Ottawa has one of the most aggressive snow removal and
salt plans going in in the first place.
So heres my question. has anyone or is there any reason not to
deliberately set up a galvanic cell by bolting an amount of magnesium
or zinc to the car body in a place where the elements can hit it? IF
i'm not "nucking futs" then the anode (Magnesium or zinc) getting wet
touching bare steel will set up a galvanic cell with the Mg being
sacrificed and "rusting/oxidizing" away to protect the steel of the
cars bodywork.
Am i nuts? is this doable? does anyone do this? Just curious?
If it matters drive a unibody car with an aluminum block (diesel jetta)
Reply to
Brent
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It works. If you make a boat out of your car. :-)
Nick
Reply to
Nick Mueller
I may be wrong, but I'm of the opinion that unless you can achieve an electrical circuit between the sacrificial anode and body and frame work of the car and the water it holds, it won't work. The mere presence of a sacrificial element isn't enough. The navy uses a similar technique whereby a ship is one pole, the ocean the other. Same with rebar and structural steel in highway overpasses.
Harold
Reply to
Harold and Susan Vordos
If I'm not mistaken, I remember seeing such devices advertized years ago in some mags. I think even one of my acquaintences even had one, No idea if it worked. ...lew...
Reply to
Lew Hartswick
On Tue, 27 Feb 2007 13:46:45 GMT, with neither quill nor qualm, Lew Hartswick quickly quoth:
Lots of people swear by them and there are lots on the market.
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f'rinstance.
-- Like they say, 99% of lawyers give the rest a bad name. ------------------------------------------------------
Reply to
Larry Jaques
Hello Brent:
You need more than 'the elements' striking the sacrificial anode. A sacrificial anode is effective on a ship or an underground tank where the *metal* *being* *protected* is in direct contact with the *solution* (ocean water or underground moisture) in which the anode is immersed.
Yeah, it kinda means that you have to drive the car under water for the anode to be effective...
An alternative is to coat the metal entirely with the anode material, as in galvanized steel.
Regards -- Terry
Reply to
prfesser
IIRC glvanizing steel is done for just that reason. (At least the name makes it sound that way.)
I read somewhere that even if the galvanizing is scratched through in one location the presence of the zinc adjacent to the scratch means that when the area gets wet the adjacent zinc takes the galvanic corrosion hit and "saves" the exposed steel.
Jeff
Reply to
Jeff Wisnia
What about those electric kits that are mounted on cars and are supposed to prevent corrosion. I am not sure how they could possibly work, in the absense of the electrolyte envelopig the car (like on boats), but maybe I am missing something.
i
Reply to
Ignoramus19052
In order to work, the sacrifical anode must be in contact with the same liquid that is doing the corroding. That's easy in water heaters and boats, not so easy in an auto which can have isolated pockets of trapped corrosive liquid.
About the best defense is frequent washing (including "bottom blast") during salt season. My Ford Contours are 12 years old, have operated all of that time in the salty Minneapolis metro area, are completely rust free thus far. They get a trip thru the carwash after every snow, once the roads are again reasonably clear and dry.
Reply to
Don Foreman
VWs have been double galvanized since at least the late 80's, IIRC, as are most current cars. The problems with your concept is that you don't have total immersion in salt water, just splashes here and there. So you need a whole lot of zinc blocks, not just one or two, which is effectively what you have with the galvanizing. It won't prevent corrosion entirely, but will slow it down. Best thing is a hot freshwater rinse after exposure.
Stan
Reply to
stans4
That's not a sacrificial anode - it's an electronic device to counter the electrolitic action. It's useless under most conditions. Daughter's Neon has one and it's rusting like all Neons.
Reply to
clare at snyder.on.ca
Move to California
Bud
Reply to
starbolins
Exactly.
My 1989 Toyota gets washed at least once a year, and there's plenty of salt used around St. Louis. I had "the Protector" put on it for a couple hundred $ when I bought it, although the dealer made a big fuss that I was throwing MY money away, as that kind of stuff is no longer needed. There are a few rusty undercarriage pieces, but the body is totally free of any rust. The car is roughly 18 years old, driven 250+ days a year, and has 163,000 miles on it. I'm sure hot-dip galvanizing is helpful, and the new paints adhere better than the traditional finishes from the 1950's, but it seems to me that the internal coating is still the best thing you can do for long life.
Jon
Reply to
Jon Elson
Jon, could you elaborate on that Protector, what is it, how it is applied, how it works etc.
i
Reply to
Ignoramus19052
[snip]
During the warmer (non snowy) months, whenever I change oil in my car, I re-paint any part of the undercarriage that shows a rock chip.
One of the issues I see with many car chassis is that the various holes trap dirt and moisture on the other side of the metal where you can't easily inspect it.
Wes
Reply to
clutch
Rather than give myself carpal tunnel syndrome again heres a link to a post addressing this issue that I made a while back on anudder group-
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This was in response to a query about Crappy Tire selling Crap. if the link doesn't work for you long story short-
Rust & galvanic corrosion are two seperate things, what works for one won't necessarily work for the other. :(
H.
Brent wrote:
Reply to
Howard Eisenhauer
Nick Mueller wrote in news: snipped-for-privacy@yadro.de:
How about an Amphicar???
Reply to
Eregon
Nice idea - Won't always work if you are close to the beach.
And there are mountainous areas in the state where they use a bit of salt - though AFAIK they try to use sand as much as possible.
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Reply to
Bruce L. Bergman
Its a good idea for other reasons. like the availability of machine tools. compared to this corner of the world I'd have likely already picked up Gunners Clausing 8540 for example at least.
Reply to
Brent
Thats a great reply explaining it. So essentially deal with paint chips and rust spots fast and its not an issue but tossing in zinc or mg just wont cut it as an effective means of preventing corrosion thanks.
Thanks to all for the posts i'm glad it generated some discussion and I came away understanding better
Reply to
Brent

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