HDPE, or high-density polythene, is a thermal plastic made, like any other plastic, from petroleum. It is often used as the material to make plastic pipes and tubes. The difference between HDPE and other plastics is that the exterior surface of the plastic is very smooth, making it somewhat difficult to bond with itself or other materials. With the use of an HDPE-specific glue, you can glue HDPE together or to another surface quickly and easily.
Sand the HDPE with 120-grit sandpaper where you want to apply the glue. If you want to glue a section of HDPE over another section, sand the top of the bottom piece and the bottom of the top piece. Wear a dust mask to prevent dust from getting in your lungs. Wipe away the dust with a damp cloth.
Mix the two parts of the HDPE glue. It is important to mix the two parts evenly and consistently to provide effective bonding. Mix the two parts together until the colour is uniform and the glue is smooth.
Scoop the glue into a caulk gun or some other dispensing container that has a small opening. Spread a 1/4-inch-wide line of glue around the edge of one of the HDPE pieces that you want to glue together.
Press the second piece of HDPE into place around the original piece where the glue is. Make sure to work quickly; the glue will only stay sticky for three minutes after application.
Allow the glue to dry for 24 hours before using the item.
Use the instructions that come with the glue if they differ from these instructions in any way.