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Why is the gas cap latch the only rusted part on my van?

Corrosion hydrocarbons? I was wondering if you can add insight as to why the latches on my gas cap cover (1994 Chevrolet Astro) are the only corroded part on my vehicle.

Would it have anything to do with the presence of a corrosive environment (petroleum or hydrocarbons) in the vicinity?

Zsolt Katzirz
automotive - Brantford, Ontario, Canada
2003

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No, the hydrocarbons aren't corrosive. Water moisture is the problem. Whether this is due to the tendency of this particular area of your van to accumulate water and hold moisture and/or road salt due to capillary action or similar cause, or due to this particular piece not being as adequately primed during manufacture, or to this being an inferior replacement piece as a result of an accident is hard to say. Good luck with it.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2003

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2003

I truly appreciate your informative response to my question, I just had one more question about your response (I hope you don't mind).

Would the hydrocarbons possibly cause the chipping away of the protective cover (paint) on the latches or maybe embrittle the paint in colder weather-----leading to the unprotected galvannealed steel---which would then turn anodic and begin the cycle of fatigue corrosion in stress areas?

Could the paint or primer be the culprit due to being too porous in cold weather allowing the hydrogen or moisture to infiltrate?

Zsolt Katzirz
automotive - Brantford, Ontario, Canada

If the paint is chipping, the most common cause is poor treatment application prior to painting.

Ronald Zeeman
Coil Coating - Brampton, ON, Canada
2003