Holy Bondo, Batman! It’s hard to tell here, but the filler where the quarter meets the trunk is well over a quarter-inch thick. Looks like whoever installed the panel attached it a bit low and just made up the difference with mud. No wonder the magnet wouldn’t stick.
We also found that the new quarter was attached to the ’68 in a strange location on the C-pillar. After getting the door open and doing a bit more detective work, we determined that a long time ago someone had replaced the entire quarter of the car, not just the panel, with a section salvaged from a donor car. Because of the techniques used we figured it had to have been done decades ago by someone in a big hurry. It was bad. Looks like we need to make another call to NPD.
We had better news while stripping the fenders. The only past problems turned out to be rusty corners that someone had patched long ago, most likely when they tried to fix the quarter. Luckily, they did a better job here.
Primer isn’t paint, and it’s not designed to protect the underlying metal over the long haul. Our ’68 had obviously been wearing its tan primer for a long time, and over the years water had gotten under it and started pitting the steel. This was pretty consistent over the entire car, with horizontal surfaces faring worse. Luckily, it’s fairly easy to address. We’re sure that folks in the “rust belt” area of the country would welcome this as their biggest problem.
Surface Rust Solution
Surface rust is one of those good news/bad news deals. The bad news is, if left untreated, it can come back to ruin whatever paintjob you lay down. The good news is, through the magic of modern technology, it’s fairly easy to take care of. The two keys to making rust a non-issue are surface preparation and sealing the metal from water and oxygen.
Here’s what we used to attack our surface rust. These products are from KBS Coatings, and their claim is that when used in concert, their products will neutralize the rust and properly seal the metal. Best of all, it’s touted as easy to use.
The first step is to sand off all the paint and old filler off the panel. We used 3M’s new Hook-It II discs in 40 and then 80 grit to quickly strip the old fenders. It’s important to make sure that all the filler and primer is gone, since any buried rust will come back to haunt you later on.
Our first step was to thoroughly clean the surface with their AuqaKleen solution and let the panel dry. Next, we attacked the panel with their RustBlast solution. We liberally applied the RustBlast and used a red 3M Scotch-Bright pad to scrub down the panel. According to KBS it’s very important to keep the panel saturated, making sure not to let the panel dry for between 10 and 40 minutes, depending on the amount of rust. Once we were satisfied with how the panel looked, we rinsed it down with water and let the surface completely dry. The RustBlast left a powdery residue of zinc phosphate behind. This coating can protect the panel from surface rust for up to 30 days.