Since most classic Mopars are nearly forty years old, it's no wonder the cars we find to build or restore have incurred some type of damage in their lives. Some have succumbed to accidents, warping and buckling their sheetmetal, and some to wear caused by many miles of use and abuse, but the main destroyer of vintage Mopar iron is rust. Depending on where you live, the cars in your area may be rusted out completely or suffer only minor damage. Cars in regions of the country where it snows regularly are usually the worst with rusted quarters, frames, and floor pans due to being driven through the salt used to melt snow from the roads. Southern cars usually fair a little better, but can have rust issues as well since the hot sun bakes the paint, leaving the sheetmetal exposed to the elements. Cars in coastal regions often don't fair any better than the ones up north as the salty air and driving on salt water laden beaches can also wreak havoc on body panels.
Our latest project, the B3 Bomber, is a Florida car and spent its entire life in the sunshine state. Fortunately, the Florida sunshine was pretty easy on our Barracuda, and the outer sheetmetal and frames are in pretty good shape. Unfortunately, our car's floorboards were almost completely rusted away and needed to be replaced.
There are many reasons a car's floors will rust. salty roads will certainly do it, as will driving on salty beaches without thoroughly cleaning your car afterwards. But there are other reasons that a car's floors will rust out. We've seen cars with no apparent external body rust with floors that are completely gone. Other than driving on salty roads or beaches, there are two basic reasons a car will have rusty floors, and both begin with the car sitting idle for a long period of time. It is common for older cars to be parked with good intentions of repairing them one day, only to find the car sits idle due to the owner's lack of interest or lack of funds. Cars that are in a garage get moved to the yard to make space and are subsequently subjected to the elements. A car parked in the grass will certainly be prone to vegetation growing under and around it, and that vegetation transfers moisture in the form of rain and dew to the bottom of the car's floors. Over time this will begin to rust the floors from underneath, and with enough time, the floorboards will be rusted away. The other problem with leaving a car sitting outside is that most old cars leak water. Weather stripping shrinking and rotting, windows left down or broken, and outer body rust-through allowing water into the car all contribute to water accumulating on the car's floors. Carpet acts like a sponge and traps the water on top of the floors, not allowing it to evaporate. This can be prevented by pulling the rubber plugs from the floors, allowing the water to drain, but most owners don't think about that when they park their vehicles. The result is, again, rusted-out floorboards