To use pipe thread sealant (often called pipe dope or joint compound) on PVC threads, you apply the sealant to the male threads, screw the connection together, and clean up any excess.
Using pipe thread sealant on PVC connections helps create a watertight seal by filling the gaps between the threads. While solvent cement creates a permanent bond for slip fittings, threaded PVC connections require a sealant to prevent leaks.
Here’s a simple breakdown of the process based on standard practice:
- Choose the Right Sealant: Ensure the pipe thread sealant you are using is compatible with PVC plastic. Some sealants are specifically designed for this purpose.
- Prepare the Threads: Make sure the external (male) and internal (female) threads are clean and free from dirt or debris.
- Apply Joint Compound: As referenced here, use a brush to spread pipe dope over the connection's external threads. Apply a liberal but not excessive amount, ensuring the threads are well covered.
- Make the Connection: Carefully screw the external threads into the internal threads. Hand-tighten first, then use appropriate tools (like strap wrenches for PVC to avoid damage) to tighten the connection snuggly. Do not overtighten, as this can crack PVC fittings.
- Wipe off Excess: Use a cloth to wipe off any excess pipe dope that is squeezed out during tightening. This keeps the joint clean and professional-looking.
Key Considerations for PVC:
- Compatibility: Always check the product label to confirm the sealant is suitable for use with PVC pipes and fittings.
- Tape vs. Dope: While PTFE thread tape is also used, pipe dope is often preferred for PVC as it lubricates the threads, making tightening easier and reducing the risk of cracking fittings compared to thread tape alone, which can sometimes create excessive stress. Some plumbers even use both for extra security.
- Cure Time: Some sealants may have a recommended cure time before pressure testing the system. Check the product instructions.
By following these steps, you can create a reliable seal on threaded PVC pipe joints.
