Plastic parts can be identified by the SAE the code, which is usually found on the rear of the part, and/or by the characteristics of the plastic. Knowing the type of plastic aids in selecting the proper repair materials and in selecting the proper repair procedure.

Look for the SAE code stamped into the part.

1. Match the code to those in the plastic identification chart to determine whether the plastic is thermoplastic or thermoset plastic, and whether the plastic is rigid or flexible. Refer to Plastic Identification and Refinishing Systems .
2. Identify any special handling procedures. Refer to Handling Precautions For Plastic .

Important: Do not use a plastic burn test in order to distinguish the types of plastics. The burn test produces vapors that are harmful to you.

Perform one or both of the following tests to determine if the part is thermoplastic (polyolefin) or thermoset (non-polyolefin).

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) floats.

•	Thermoset (non-polyolefin) sinks.

Thermoplastic and thermoset plastics can be either rigid or flexible. Thermoplastic plastic parts are best repaired with a hot iron plastic material-feed welder, but are usually replaced. Thermoset plastic can be repaired with epoxy or other more rigid two package repair material.