We’ve been working on A pillar patches this week, and it’s pretty interesting, particularly since this is a common area of concern on all Sprites and many other classic British cars, as well. All too often, these cars are beautiful, but you’ll find some blisters in the A pillar area, which can ruin an otherwise show-quality car.  

Water enters the A pillar cavity (that’s the rectangular pillar directly in front of the door hinges) through the windshield post mounting holes. You can see in our photos below that the front windshield mounting threaded hole is a direct link to the cavity where we often see rust blisters on Sprites. Once the water runs down that hole it gets trapped with no drainage and can sometimes rust the top of the rocker panel as well. 

In general, this is nothing more than a nuisance and not a particularly structurally consequential issue, because the rust is usually contained to the small A pillar lower portion. The first patch that you see below is a simple repair of a very small rectangular area where we cut out the rusted area, treated the metal to prevent further rust, and then welded in a small patch. It’s one of the easiest rust repairs you can ever take-on… it’s very satisfying  and manageable, and blisters such as these are not usually indicative of larger rust problems throughout the car– it’s usually a localized problem.