To expand the diameter of PVC pipe, a common and effective method involves heating the pipe to make it pliable, then inserting another pipe or form into the heated opening.
According to one method, a heat gun is the tool of choice for this task. PVC is very pliable when you heat it up. The process involves heating up the inside of the end of the PVC pipe you wish to expand and then simply shoving the other pipe through it. This allows the heated, softened PVC to stretch and conform to the shape of the inserted pipe, effectively increasing its inner diameter at that point.
Why Expand PVC Pipe?
Expanding the end of a PVC pipe allows for a snug, solvent-welded connection without the need for a separate coupling fitting. This can be useful in custom plumbing or fabrication projects where standard fittings aren't ideal or available.
The Heat Gun Method: Step-by-Step
Expanding PVC pipe using a heat gun is a relatively simple process, but requires careful handling of heated material.
Here are the basic steps based on the referenced technique:
- Gather Your Tools: You will need a heat gun, the PVC pipe you want to expand, and the pipe or fitting you intend to insert into it (this will act as your form).
- Prepare the Pipe: Ensure the end of the PVC pipe to be expanded is clean and cut squarely.
- Apply Heat: Using the heat gun, direct hot air at the inside of the end of the PVC pipe. Rotate the pipe evenly to ensure uniform heating. The goal is to make the material pliable, not melt it. You'll see a slight change in the pipe's rigidity as it softens.
- Insert the Form: Once the PVC is sufficiently heated and pliable, quickly but carefully shove the other pipe or fitting into the heated end. Push it in until you achieve the desired depth of expansion.
- Cool Down: Hold the pipes in place as the heated PVC cools and hardens around the inserted form. This will typically take a few minutes. You can sometimes speed up the cooling process by gently running cool water over the exterior of the joint, though allowing it to cool naturally is also effective.
- Remove the Form: Once completely cool and rigid, the inserted pipe or form can be removed, leaving the end of the original pipe expanded to the new diameter.
- Note: The reference specifically mentions heating the "inside" of the pipe, which is key to making the material ready for the internal pressure of the inserted pipe.
Safety First When Working with Heated PVC
Working with heated PVC requires caution to avoid burns and inhaling fumes.
| Safety Precaution | Description |
|---|---|
| Ventilation | Work in a well-ventilated area. PVC can release fumes when heated. |
| Gloves | Wear heat-resistant gloves to protect your hands. |
| Eye Protection | Always wear safety glasses to protect against accidental contact or debris. |
| Avoid Overheating | Do not hold the heat gun in one spot too long; aim for pliability, not melting or burning. |
| Secure Workpiece | Ensure the pipe is stable while heating and inserting the form. |
Using a heat gun makes the PVC very pliable and allows for successful expansion when another pipe is inserted, as highlighted by the referenced method.
