Electronic rust prevention module

[enigma-2]

Just bought a used 2009 Lincoln MKX and while checking out the car on the lot, was amazed that there was no rust on the under-body. No undercoating either. (I actually crawled under the car on the lot to check out the under-body). Anyway, that's pretty much unheard of here in Northern Indiana with all the salt they use on the roads. County highway started using a liquid slurry a few years back that's even worst for cars. Car's history was Michigan, then Ohio and finally they moved to Northern Indiana. So It's been continuously exposed to road salt. The dealer told me they don't undercoat anymore, just put one of these modules on. Six year-old car and not a speck of rust on the under-body.

 

I had never heard of an electronic module that stops a car from rusting, but this one had it one it since new. The previous owner took the module off and took it with him, so I decided to have a new one put on. It has a 10-year warranty through the dealer against rusting. (Dealer's body shop takes care of any rust that pops up).

 

According to the literature they gave me, it only works on cars that have galvanized bodies (doesn't work on bare steel). When a stone hits to under-body, it breaks the galvanized coating, exposing the steel. The galvanizing starts to bleed over the injured area, however before it can completely, there is some sort of reaction (an oxide forms) and slow or prevents the galvanizing from completing the repair, before the rust starts. I guess the way it works is, the module sends out a pulsating RF frequency wave and is supposed to prevent the oxide from forming, allowing time for the galvanizing to cover the wound.

 

My last car was undercoated and had rusted out all over the underbody from the salt. Used to run it through the local car wash during the winter months as well. (Reason I traded it, damage got to be too extensive to repair any longer.

 

Anyone had any experience with one of these modules? I've read that they're snake oil & not effective on cars, but seeing how clean it was underneath shocked me, nearly like new (even through it had gone through six winters in the north).

Edited November 15, 2014 by enigma-2

[akirby]

They're very common on boats.