How to repair rust- Fixing a rusty windshield cowl

So you decided to give your car a refreshing new look and it’s time to strip it down to prepare the car for paint. You can count on finding some sort of surprise when tearing the vehicle down. Whether it’s hidden accident damage, previous repairs, or the mummy of a dead animal; it’s always an adventure when stripping a car or truck down for paint or bodywork.

I recently started tearing into my “clean” (for the east coast at least!) 1977 VW Scirocco I’ve owned for a few years. It had some wear and tear and some bubbling paint I wanted to address before it got a fresh lick of paint. When I began removing the fenders I was pretty surprised to find some rot in the inner fender and windshield cowl. I decided to take some photos as I repaired this area and share some tips for making a repair that will look original when done.

Here is the offending area when I removed the fender. The worst rot was in an area that sandwiched between the fender and cowl and was covered with weather stripping. So from first glance it just looked like some bubbled paint, but that was the tip of the iceberg.

I first cut out the area that was rotted until I got to solid metal and a nice seam where I could weld and blend the panel into the original metal.

I started making my patch panel by bending up a piece of construction paper to the rough size I needed, then I transferred the rough shape over and cut it out of 20 gauge aluminized steel. Next I measured the other side and marked out the bend line I needed to make.

In order to make a clean bend in the new metal I needed a metal brake. I decided to use the Versa Bend Sheet Metal Brake and put a crisp 90 degree bend in the panel on my line.

With the patch panel now formed into the rough size I needed, I took it to the car and trimmed it to fit the opening. It’s here that you want to make sure the patch panel fits tightly so that you don’t need any excessive welding to fill voids.

I then setup the MIG 135 with .023 Solid Core MIG Wire so I could lay small, flat spot welds on the patch panel. Setting the machine up on a similar piece of scrap metal helped me get my spot welds laying flat and penetrating correctly. After finessing the panel with Eastwood Hammers and Dollies and blending the welds with a flap disc on an angle grinder I was satisfied with the repair. I’m happy to say the patch panel looks close to original and the repair should be invisible once it has primer and a top coat on it. Now onto the next surprise!