What is the first rule when working with plastics?

The first rule when working with plastics is identifying the material that has been used. This step is crucial because different types of plastics have unique properties, compatibility with certain products, and specific preparation and finishing requirements. Understanding the type of plastic allows for the selection of appropriate cleaning agents, primers, paints, and adhesives, ensuring that the finishing process adheres properly and lasts long. Additionally, some plastics may require specialized techniques to prevent damage during sanding or painting, making identification essential for successful refinishing.

While using abrasive materials, applying primer, and cleaning with solvents are important aspects of working with plastics, they all hinge on first knowing what type of plastic is being dealt with. Each material's response to these processes can vary significantly, which is why proper identification cannot be overlooked.