Now, today we won’t be talking about a specific make and model of car. Instead, I’ll be sharing some thoughts on something every classic car enthusiast knows well and wholeheartedly despises: rust. A chemist will tell you that it’s a simple oxidation reaction that occurs when exposed steel comes into contact with oxygen, whether just from the atmosphere or from something like water. On the other hand, a car guy will tell you that it is the automotive equivalent of cancer. It spreads rampantly, often hidden under failed paint, or undercoating waiting to kill your beloved automobile. While one might make the argument that it’s nature’s way of breaking down steel so man’s iron creations don’t pollute the environment until the end of time, we want to enjoy our classic cars for as long as possible. There are few words that come to mind which I feel can truly express the dread associated with discovering covert rust creeping along in some out of view corner of your vehicle eating away at it. I’m not exaggerating when I say that when I discovered some rust in the battery tray of my 1986 BMW 325e I felt like a doctor told me that a family member has cancer. 

Take a stroll down the paint aisle of your local auto parts store and you’ll see shelves full of products purporting to convert pesky rust to a safe, paintable finish. These chemicals convert “red” rust (the dangerous kind) to “black” rust which is safe to paint over and will not spread. Unfortunately, this is not the cure-all it appears to be. While it will convert the top level of rust to non-damaging black oxidation, it cannot penetrate through all of the corrosion, so it will slow the spread, but will not completely rid your body panels of this chemical cancer. The only way to fix it is to completely strip the rust from the panel in question and repaint with a quality primer and topcoat. If the rust has gotten so bad that it has eaten holes, the panel should be cut and patched with fresh metal. 

Remember, the best offense is a solid defense. This is as true for corrosion as for anything else. Use a quality oil-wax coating on the undercarriage of your vehicle to protect it from road salt and make sure to address leaks that can cause water to pool in panels and rust to form. Avoid rubberized undercoatings which separate from the metal and trap water leading to incessant corrosion and always be vigilant of paint damage before it leads to corrosion and costly repairs.