Plastic Bumper Repair

Step 2 Grind a "V"

After the solvent has dried, sand the area by hand with 80-grit paper. Next, you'll need to form a "V" groove in the damaged area on the front and back sides of the fascia. The grooves allow you to align the two edges more easily. They also provide more surface area for the repair material to adhere to. For plastic types that powder when sanded (PUR, TPUR), cut the grooves with a 24-grit disc on a sander. For plastics that smear when sanded (PP, PPO, TPE), make the grooves using a cordless drill and a rotary file.