The Subaru Impreza is 15 years old and has needed some TLC for awhile now. A few years back when I set up the new studio I ground out a few rust blooms and repainted them. I shied away from the wheel well by the gas tank, thinking sparks and gas fumes and “boom!”. My local mechanic is amazed at the car’s mechanical fortitude, and predicting that it will last another 100k miles thought a little body work at our friendly local auto body shop a worthwhile investment. I swung it by for an estimate and they recommended replacing the whole panel- parts and labor were about 1/4 what we paid for the car. So we ignored that whole scenario and since then I’ve noticed auto body guys welding all around under cars and got over my jitters. This spot was left to fester for three years, and I had to cut away about 7 inches x 3 inches of corroded steel. My guess is that a drain between the body panels was plugged with dirt, as both walls needed cutting.
With this big of an area to float, I used a formable mesh wire. I cut straws and put them between the body panels and behind the wire to allow water to pour through. Then it was bondo time. I skinned the wire with bondo and let that set up, then did another layer of bondo from behind and filled in more on the front. I ground that down and added another layer to the front. Then it was tooling with the pneumatic disk grinder to shape it to match the panels. It could have used another thin layer of bondo and fussy finish sanding, but I had lost the sun and the bondo was kicking slowly enough that I brought out the heat gun to help it along. I decided that “good enough” was going to be good enough and wiped the area down with acetone and taped off the boundary. Then it was primer coat, then topcoat just as the light faded and the temperatures sank below spray-paint level.
We’ll see if the repair survives a Utah winter.