A How-To Guide On Welding Plastic For those people who have never before welded plastic, it is a slightly different process than welding metal, however, plastic welding repairs is still something which can be done with enough patience and caution. 1. The first step in welding plastic is to let the welding gun heat up for at least 20 minutes. This will ensure the gun is at a high enough temperature to be able to melt the plastic. 2. While the gun is warming up, remove the plastic piece from the object if need be. No matter if the plastic needs to be removed or not, make sure to clean it thoroughly with a mild detergent and water. A clean rag should be used to wipe away any dirt and grime which may have accumulated on the plastic. 3. At the areas of the plastic which need to be welded, sand them down with sandpaper rated at 80-grit until the plastic is completely smooth. 4. The next step will be to hold the joints of the plastic in place. This is typically done one of two ways. The simplest way is to use foil tape to tape the joints together in the exact position they need to be welded in. After the plastic is welded together, the foil tape is gently removed. Another way is to use a soldering gun to hold them together in a process called “tacking.” The soldering gun needs to be warm enough to just barely melt the plastic, it should not be hot enough where the plastic will begin to smoke when the soldering gun is placed on it. 5. When the welding gun is fully heated, the welding rod should be inserted into the welding gun. The rod acts as a focal point for the hot air coming from the welding gun and aids in directing it to where it needs to go. After these steps are complete, you can now proceed to engage in plastic welding repairs . If this sounds like too much trouble or you do not own the necessary equipment, make sure to call a professional company to do the job for you.