The plastic pipe protects the metal parts from natural forces like wind, salt, and ultra-violet rays. And, because we don't have to use more expensive materials like aluminum, we can pass the savings on to our customers. In most cases, the plastic pipe is holding a copper radiator along with matching device, etc. To determine whether a particular brand has metallic content, put a small piece of it in a microwave oven, along with a glass of water, for a minute or two. If the PVC feels warm to the touch, it has some metallic content.
Plastic pipe is amazingly flexible, yet it maintains it's shape over the years.
Of course, Mother Nature always has a few tricks up her sleeve, but Q-Stick Antennas are champs when it comes to standing up to wind. In most cases, some glue and an appropriate coupling from the hardware or plumbing store is all that's needed to get things back together. Poorly made connectors can introduce up to 3 dB loss into your antenna system. Use black plastic tape or a sealing compound to keep the center conductor and braid apart. The instruction sheet furnished with each Q-Stick Antenna has information regarding mounting, including the type and size of mounting piece recommended.