Plastic Radiator Repair: How to Repair a Plastic Radiator Tank

What You'll Need
Plastic welder
V Groove tool
Heat gun

Plastic radiator repair is something that you will have to do carefully. When it comes to a plastic radiator, a lot of the same methods you would use for a regular radiator do not apply. A plastic radiator tank is a lot more difficult to work with if you do not know the proper way to handle the repair part of it.

Step 1 – Understand Plastic Radiators

Adhesives are no good for plastic radiator tanks as the pressure as well as the temperature will prevent the adhesive from doing its job. Plastic radiators can handle high pressures and temperatures. It is used with nylon which has a very high melting point. In addition to the nylon glass fibers are added to give the tank strength to withstand the added pressure. Understanding how plastic radiators work will help you to work on them.

Step 2 – Penetration

It is important that you are able to get good penetration whenever you are welding on nylon radiator tanks. The best way to do this is with a "V" grooving tool. You will use this tool in the cracks. If you unable to get one of these tools, then you will be able to use the tip of your welder for this task. While you do this it is normal to hear crackling sounds. It is the glass fibers and is something that is supposed to happen.

Step 3 – Preheat

Because nylon has such a high melting point, you may want to consider preheating it with a heat gun. This will help to make your heating process go much faster. You will simply need to get the heat gun pointed in the area you wish to work on first. When the plastic starts to look glossy step back a couple of minutes so that the heat will be able to go through. Whenever you feel like the heat has been completely soaked through the plastic then you are ready to begin.

Step 4 – Weld

With preheating done, you are ready to get your nylon welding rod out and get about an inch of melted rod laid down. You will need to get the welder and the rod separated and work your melted rod into the nylon. Do this until you have a good mixture; you will know when this is done because the radiator and the rod will become the same color. You will need to continue to do this until the base material is mixed well. While it can be frustrating, it is a good idea to weld about an inch at a time. This will keep the nylon from cooling before you are able to start work on it.

Step 5 – Finishing Up

Once you have the area mixed well you are ready to finish up. You will simply need to get the tip of the welder and smooth out the area as best you can. Do this until the entire base is smooth and looks like new again.