Sometimes there’s just nothing left to polish. This is especially true with cars from the 90’s. When the auto industry switched over to water-based clear coat paints, many of the earlier products started to fail before the new-car warranty even expired. The other area which caused problems was in door jams and trunks. The flexible weather stripping holds water and the pinch welds were notoriously poorly painted. Over time the metal begins to rust. Left untreated there just isn’t any metal left.
This E36 M3 was heading down that road, but fortunately we caught it in time. Normally, with this much rust, I’d recommend the panel be cut out and a replacement spliced in. But since this is a dedicated track car, the owner asked what I could do to just stop it from getting worse and make it look better.
I removed the taillights, trunk gasket, and trim. Removed as much of the rust as possible with a wire wheel, and then applied rust converting primer. Once the primer dried, I applied body filler, sanded, primed again, more filler to refine, more primer and then painted. I put a 1K clear coat over the base coat when done. It’s not perfect, but certainly far better than when I started. The rear face of the trunk lid I corrected, polished and ceramic coated. The bumper I repaired and resprayed, but that’s a tale for another time.
