Before you get excited, we're not talking about taking washed-up, constantly boozing musicians whose dependence on distilled spirits and narcotics will serve as our entertainment. We'll leave that to Fox. What we're talking about are rocker panels. On an old car, where water collects, rust happens. By the mid-to-late '60s, GM had made the fantastic decision to start using galvanized steel for rocker panels and other parts of their cars. Galvanizing is the process where a piece of steel is dipped in a molten bath of zinc (somewhere around 860 degrees) then exposed to air. The pure zinc (Zn) reacts with oxygen (O2) to form zinc oxide (ZnO), which further reacts with carbon dioxide (CO2) to form zinc carbonate (ZnCO3). Zinc carbonate is usually a dull gray, fairly strong material that stops further corrosion in many circumstances, protecting the steel below from the elements. Galvanized steel can be identified by the crystallization pattern on the surface (often called "spangle"). Unfortunately for us, our '55 hardtop predates this wonderful decision by GM, which means anywhere that saw moisture constantly is rusted. Our beloved '55s have some common areas where they like to rust because water collects in various nooks and crannies of the body. Among these are the "eyebrows" of the front fenders, inside at the base of the kick panel vents, the front corner of the quarter panel just behind the doors (two-door models), and in the tail pan area. Because this hardtop spent a major part of its life in the tropical climate of South Florida, it's got the usual rust issues. In our last installment, we installed a new tail pan piece and its related body mount/brace. Moving forward, we wanted to get the rocker area repaired before starting on the quarter-panel patch process. As you'll see, this made replacing the inner rocker much easier. Once again Jim and Tommy Barber at Classic Automotive Restoration Specialists (CARS) were the wrenches on our project, and have been just as amused as we were to find some of the hidden things about our '55. So far we've found parts of two different '55s used in different repairs on the car and have clearly identified that the hardtop's been painted at least five different colors in its life. Ok, I'm done babbling; let's get to the story! 1 Here you can see the other common area for rust on two-door Tri-Fives, the front corner of the quarter-panel just before the door. Also visible is the seam between he outer rocker and quarter, where rust ate away at the seam. The lead filler used at the factory for seams is notorious for trapping moisture and creating a breeding ground for corrosion. 1 Here you can see the other common area for rust on two-door Tri-Fives, the front corner 2 While the outer rocker ends with the door, the inner rocker panel goes all the way back behind the quarter panel. The bubbly surface tells us there's trouble lurking behind here too, which we'll expose when we cut away the quarter so the inner rocker can be replaced. We'll cover the quarter-panel repair in a later. 2 While the outer rocker ends with the door, the inner rocker panel goes all the way back 3 Up top, the sill area looked OK minus a couple of pinhole rust spots. In places like this, you can still sea a lot of the car's original coral paint. The sill cover plate wasn't so lucky, but Danchuk shipped us new ones to install once all the bodywork is finished. If you've got a Tri-Five and are wondering about its original color, the sill area is a good place to look for remnants of it. 3 Up top, the sill area looked OK minus a couple of pinhole rust spots. In places like th 1 | 2 | » | View Full Article By Patrick Hill Enjoyed this Post? Subscribe to our RSS Feed, or use your favorite social media to recommend us to friends and colleagues!