Growing up in Australia, my elder brother was very adept at fixing rust.He could make up any shape to replace the oxidized metal he had removed.After this,he would use liberal coats of "fish oil" to prevent any more "cancer", as he put it,returning.Often he would also remark about how Porsches were galvanized and so didn't rust-but how true is this? Is the whole body dipped or sprayed with something? Is it an electro-chemical process? What has been your experience with rust? What is the latest Porsche you have seen it in? Is there any point using fish oil on a Porsche?

 

the entire body is galvanized and coated in cathodic dip before painting.

i read somewhere the engines are galvanized too.

evidently they are pretty confident in it, as there is a 10 year anti rust warranty.

 

Well This is a good post for me to chime in, I am in the steel industry, I supply different types of metals to most of the Auto manufacturers.The main reason Galv is better then standard carbon(non coated products) is simple. Galv will corrode more then rust, the only way galv rusts is from the inside out, where as non coated rusts from both ways.Galv is not widely used in the auto market, unless it is a " an exposed part" It is very expensive in comparison to non coated products. There are many types of products the auto makers use such as: Aluminized, galvalum, galanealed . Galv will rot over time, but studys have shown that a coated product will last 4 times longer then just the industry standard of painted steel. So to anwser your question, galv is 4 times better then the industry standards..Fish oil what the hell is that?

 

The zinc in galvanzing is sacrificial so it will give itself up to save the steel beneath. the other neat thing is the zinc can migrate to cover a small void, but only up to a point. Once the zinc is 'used up' the steel can rust, but if there is no exposure to corrosives or elecrolytic action this can be a very long time. The tricky bit is painting zinc coated surfaces but somehow Porsche has solved that one nicely. I would forget the oil unless its a matter of: why not?
Do seagulls follow your car around? that might be a worse corrosive situation

 

I've always used Naval Jelly on rusted things and then painted them. It's a rust converter that turns the rust black. It somehow bonds with the rust to prevent it from rusting any further.

 

The yellow zinc chromate rusty steel primer I used years ago had 7% fish oil in it.

 

don't forget though, the rest of the cars components will still take a beating unless properly washed on a consistent basis for the winter. They only galvanize the body panels; the warranty is clear on this aspect.