How to Use a Plastic Hot Air Welder

Fabricating and repairing plastic often requires fusing two or more pieces of plastic together. Thermosetting and thermoplastic are the two types of plastics, but only thermoplastics are weldable. Fortunately, the majority of plastics used in both the construction and automotive industries are thermoplastics, which weld readily with a plastic hot air welder. Identifying the type of thermoplastic you intend to weld is important, as each type of thermoplastic has a different weld and melting temperature.

Instructions

1

Examine the plastic you need to weld. Look for an three-digit identification number molded into the surface of the plastic part. If you are using plastic sheets, the identification will be printed in the surface of the plastic.

2

Locate the three-digit identification code in the plastic identification book and find the welding temperature for that specific type of plastic.

3

Plug in the plastic hot air welder and turn the temperature dial to the temperature specified in the plastic identification book for the type of plastic you are welding. Set the plastic hot air welder down and allow the welder to warm up to the set temperature.

4

Turn on the die-grinder and run the spinning carbide tip along the edges of the plastic that will be welded together. If you are repairing a piece of plastic, you need to make a 1/16 to 1/8-inch deep groove along the entire length of the repair.

5

Slide the pieces of plastic together so that the beveled ends of the plastic sheets fit tightly together, or align both sides of the plastic repair so both sides of the repair are even.

6

Clean the weld area with the 80-grit sandpaper. Keep the area free of grease, grime and paint. When welding new pieces of plastic, you can skip this step, as the manufacturing film left on the plastic will have been removed in the previous step.

7

Heat the end of the plastic filler rod with the plastic hot air welder, while you heat both surfaces of the plastic that need to be welded.

8

Place the end of the heated filler rod onto the heated section of the plastic weld joint and apply downward pressure on the plastic filler rod to bond the filler rod with the plastic weld joint.

9

Continue applying downward pressure on the filler rod as you heat the area where the filler rod meets the surface of the plastic weld joint. Move slowly so that the plastic filler rod and the plastic weld joint will have time to bond properly. To ensure a proper bond, watch the area where the plastic filler rod meets the plastic weld joint. You will notice a small bead of melted plastic riding in front of the plastic filler rod.

10

Clip the end of the plastic filler rod with the side-cutting pliers when you have reached the end of the plastic weld joint to complete the weld joint.

11

Allow the weld joint to cool before you handle the welded pieces of plastic, as the weld joint will be extremely hot after it has been welded.