C3 Corvette Bumper Repair - Rubber Revamp

To fill minute imperfections, such as sanding scratches or pinholes that inevitably appear once the primer is sprayed, we used regular air-dry acrylic spot putty.

A guidecoat is a contrasting color sprayed in a light fog over the primer coat. We used some surplus orange basecoat we had, which makes an easy-to-see guidecoat over gray primer.

Our second primer application was sanded with No. 320 dry, using a flexible hand block and light pressure. The urethane bumper cover is flexible, so sanding requires a light touch and sharp, fresh abrasives. Note how the contrasting guidecoat shows when the surface has been sanded to a smooth, even finish. Once fully sanded, we sanded again with No. 600 in preparation for paint.

We had the factory white hue mixed to code at a local paint supply, selecting single-stage DuPont Centari acrylic enamel. A universal flex additive can be added to the paint to make it more pliable on the flexible urethane bumper cover.

We shot the cover with a light tack coat first, followed by two medium wet coats. The white paint covered quickly and flowed out nicely, providing an OEM look.

A close look fails to reveal any hint of the damaged right corner's cracks after the repairs were made.

Overall, fixing the bumper cap gave our old C3 a much cleaner look. Though the paint on this car is far from perfect, the cracked and peppered bumper was by far the worst looking area. A few minor repairs can make a big difference.