wakeech

i've read some concerns about rusting over the winter, concerns about the paint and whatnot, and just this morning "it" hit me: "catalytic" (that's what i remember it as, although i know it's wrong) oxidation protection. it was in my grade 11 chem class that my teacher (who's a car nut and karter) put oxidation into practical terms talking about his Pathfinder.
to protect it, he uses the same methods as out-board motor builders do and bolts a chunk of zinc to the motor, which protects even the barest mild steel from corrosion in salt water.

"how is this possible?" you ask: it's pretty simple, the zinc has electrons in lower-energy orbits than the steel does, and thus the zinc will give off (oxidize) ALL of its electrons before the Fe/Ni/Al/whatever does. the salt water ions (Na+) as they pull these electrons away (reduction) create ions of Zinc, dissolving it in the water, and it slowly "breaks down", meaning you have to change it (every few years).

it occured to me that some would be interested maybe in talking to their dealer about having a system (well "system": it's unbelievably simple) installed at their local dealer (to avoid voiding the warranty).
you just need to have bare-metal contact between the chassis (as a unibody, it doens't matter where: it could be somewhere in the boot) and the big chunk of zinc you bolt onto it. after that, even the worst road salt and sand will not rust out the chassis of your car, or anything that has a bare-metal-to-metal contact point with it.

thoughts?

babylou

You meant "cathodic" protection.

wakeech

RIIIIIIIIIGHT

thanks.

Doctorr

Yes cathodic protection, it would be great if automakers would use more galvanised metal, but it's not likely.
You would have to bolt the chunk'o'zinc onto the body so it becomes part of the reaction, that is it would have to be in the 'electrolyte' involved.
For instance, if you are trying to protect your door sills & rocker panels from salty water corrosion, you would have to place the sacrificial anode in the salty water also (the outboard motor protection is on the 'leg' below the water line).
.....Likewise the muffler, it is necessary to attach the zinc onto the steel, with a really good low resistance contact - and if it corrodes (which IS the point) you have to ensure the contact is not lost between the metals.
.....Just bolting it to the wheel-arch inside the trunk doesn't count (but nice try!)
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Doc

wakeech

really?? my chem teacher actually does this, and he says it works really well for him...

eccles

Either he's experiencing the placebo effect, or he has major water leaks inside his trunk.

VWjet

I was perusing and found this site.

http://www.corrosionvci.com/Auto_Rust_Protection/

$300 sounds pretty hefty. I've followed my father's lead and used Ziebart for my vehicle and its worked great so far. Just a yearly check-up for the balance of the car's life and you're all set!