Before getting started on a repair, knowing what type of material you’re dealing with is critical for a successful job, not to mention a satisfied customer. (See Service Document ID #2083204.)

Whether it’s a bumper fascia, spoiler or any non-metallic body part, identifying the type of plastic that makes up the item is important when selecting the proper materials and repair procedures that are needed. Note: It is recommended that you replace, rather than repair, any bumper fascia on vehicles equipped with the Advanced Driver Assist System (ADAS). The exception is for primer and topcoat finishing, as long as the total paint thickness doesn’t exceed 13 mils.


Plastic parts can be identified by an SAE code that is typically stamped on the rear of the part. Match the code(s) with the one found in the Plastic Identification and Refinishing Systems section of Service Information (SI). This will help you determine whether the part is a thermoplastic or a thermoset material, and whether it is rigid or flexible.

If no SAE code is found, perform one or both of the following tests to determine whether the part is a thermoplastic polyolefin or a thermoset non-polyolefin. 

Float test

  1. Cut a shaving of plastic from the back of the part. The shaving should be free of mold release agents and paint.
  2. Place the shaving in a container of water. Thermoplastic polyolefin will float; thermoset non-polyolefin will sink.

Abrasion test

Using a Grade 36 Roloc™ Disc, sand a spot near the damaged area. Thermoplastic polyolefin material will melt or fray while thermoset non-polyolefin material will sand cleanly.

Also, thermoplastic and thermoset parts can be either rigid or flexible. Thermoplastic parts are best repaired with a hot iron, plastic material-feed welder, but are often simply replaced. Thermosets, on the other hand, can be repaired with epoxy or a more rigid 2-package repair material.

Click here for the Plastic Identification and Refinishing Systems chart.