- 1). Drain the fuel from the plastic tank. Remove the tank from the vehicle.
- 2). Pour a mixture of dishwashing soap and water into the top of the fuel tank. Slosh the mixture around, then dump the soapy solution from the tank. Repeat the procedure two more times to remove fuel residue and fumes from the tank.
- 3). Plug in the plastic welding gun. Set the welder to the temperature designated on the heat requirement chart affixed to the welder box. Turn on the welder.
- 4). Wipe the cracked seam with a clean rag soaked in the soap solution. Rinse the seam with clean water. Allow the seam to dry.
- 5). Run the point of a triangle file along the cracked seam to create a 1/16 inch V-groove.
- 6). File the raised edges left by the file from the area with 400-grit sandpaper.
- 7). Place the tip of the plastic welder on one end of the cracked plastic seam. Push a plastic filler rod into the top socket of the welding tip as you slowly pull the welder along the seam. Pull the plastic welder away from the fuel tank when you reach the opposite end of the cracked seam, leaving the excess filler rod attached to the tank.
- 8). Cut the excess filler rod from the tank with a pair of wire cutters.
- 9). Allow the repaired seam to cool before installing the tank back into the vehicle.