The Most Effective Fix for Cracked PP-TD20 Interior Car Panels
When dealing with a cracked interior car panel made of PP-TD20 (polypropylene terpolymer), the age-old question arises: should you glue it or weld it? In this article, we will explore the best methods to fix a cracked PP-TD20 panel, emphasizing the advantages of welding and an innovative permanent fix involving a fine-woven metal screen.
Welding as the Preferred Method
Welding is often the most effective way to repair these types of plastics. From my decades of experience in the collision repair industry, I can confidently assert that welding is the superior choice. It is particularly effective when you can access the back side of the panel and have the crack completely closed.
Using a small torch or heating source like a butane lighter, butane candle lighter, or a Bernzomatic torch, carefully heat the crack just enough to close it. With precise heat application, you can then place a small piece of fine-woven metal screen over the crack and melt it into the plastic. This technique is not only strong but also aesthetically pleasing and long-lasting.
Alternative Repair Method with Metal Screen
If you lack the knowledge or tools for welding, or if welding is not feasible, an alternative method can be surprisingly effective. This involves using a fine-woven metal screen, which can be found at a hardware store. These screens are similar to screen door screens but have a more robust and sturdy structure.
Start by cutting a small piece of the metal screen to fit the crack. Hold the piece in place with needle-nose pliers or oversized tweezers. Using a small heating source, reheat the screen to red-hot and immediately place it over the crack. The heat will melt the plastic, and the screen will be embedded, effectively locking the crack closed.
This method is incredibly strong and durable. The screen acts as a form of rebar, reinforcing the plastic and ensuring a permanent fix. This technique is so effective that it often exceeds the strength of the original panel.
Additional Tips for Successful Repairs
If you encounter any issues while attempting to prepare the area for welding or the metal screen method, a very small dose of super glue can provide a temporary bond, allowing you to continue with the repair process.
My experience in the collision repair industry, with over three decades of working with various plastic parts, has shown that even severely damaged panels can be repaired using these techniques. I have personally repaired bumper covers that were completely torn in half and have seen the same panels after five years, still in perfect condition.
Conclusion
In summary, for repairing cracked PP-TD20 interior car panels, welding is the preferred method due to its strength and permanence. However, if welding is not an option, using a fine-woven metal screen offers a strong and durable alternative. With the proper technique and tools, you can achieve a near-perfect repair that no glue or epoxy can match. This is a testament to the durability and reliability of both welding and the metal screen method, making them indispensable tools for any collision repair professional.