Buzz
This is the white plastic commonly used in plumbing and drainage systems. PVC stands for polyvinyl chloride. Comstock / Getty ImagesWhether you're fixing an error or upgrading an old fixture, there are times when you'll need to separate Polyvinyl Chloride (PVC) pipe. While dissolving the solvent between PVC pieces is impossible [source: This Old House], there is a method to remove PVC pipe glue.
With the right tools and techniques, you can successfully detach PVC pipe. The trick is knowing which methods to use and which to avoid!
Understanding PVC Glue
Before learning how to unglue PVC pipe, it’s essential to grasp the properties of PVC adhesives. PVC glue, or PVC cement, is a solvent-based adhesive that works by softening the surface of the PVC pipe and fitting. Once the solvent evaporates, the two parts bond together, often creating a joint stronger than the pipe itself.
Essential Tools for Gluing PVC Pipe
Here’s what you’ll need:
Hacksaw
A hacksaw is essential when you can't physically separate a glued PVC joint by heating and twisting. In these situations, a hacksaw allows you to carefully cut through the PVC pipe near the joint, enabling you to remove the glued section of the pipe. It’s a reliable tool for making precise cuts in PVC pipes.
Purple Primer
Purple primer is used to prepare the surface of the PVC pipe before applying cement for reattachment. It cleans the pipe by removing dirt, oil, and any leftover adhesive, ensuring a clean surface for the new glue.
The primer also softens the outer layer of the PVC, promoting a stronger bond when the new cement is applied. Its purple color makes it easy to see where it’s been applied, ensuring full coverage of the pipe.
Clear PVC Cement
After applying the primer, clear PVC cement is used to create a fresh bond between PVC pipes or fittings. This solvent-based cement chemically melts the surfaces of the PVC pieces, effectively bonding them into a strong, durable seal.
Clear PVC cement is ideal for situations where the visual appearance matters, as it leaves no visible color marks on the pipe. Keep in mind that not all solvent cements are the same!
A New Fitting and Coupling
When a PVC pipe is cut to remove a glued joint, a new fitting or coupling might be needed to reconnect the pieces. The new fitting can be attached to the existing pipe using PVC primer and cement. Couplings are particularly helpful when joining two cut ends of pipe together, ensuring a solid and leak-resistant connection.
How to "Unglue" and Re-glue PVC Pipes
Here's how to proceed:
- Remove the damaged joint Use a hacksaw to carefully cut the PVC pipe flush against the fitting of the joint you want to separate [source: This Old House].
- Obtain a new fitting and coupling Choose a new fitting that suits your needs. Ensure the coupling matches both the old fitting you didn’t cut and the new one you’re adding.
- Apply primer to the PVC Coat the ends of your PVC fittings with a thin layer of purple primer. Apply primer to the inside of the coupling as well. Allow it to dry for a few minutes.
- Assemble the new joint Once the primer has dried, apply clear PVC cement to the primed areas of both the pipes and the coupling. Make sure to use a PVC-specific cement, as some multi-purpose glues aren’t suitable for all pipe types. Push the pipe into the coupling, twisting it a quarter turn. Ensure the fittings stay in place before the adhesive sets. If necessary, wipe away any excess glue before it hardens.
Avoid the Heat Method
Using a heat gun or propane torch on PVC pipes can be hazardous due to the high temperatures involved and the nature of PVC. When exposed to excessive heat, PVC can release toxic fumes, such as chlorine gas and dioxins, which are harmful to your health and can cause respiratory issues, eye irritation, and other problems. This risk increases in poorly ventilated spaces where these fumes can accumulate.
Furthermore, applying excessive heat to PVC can cause the pipe to melt or warp, compromising its strength and potentially resulting in leaks or breaks in the system. There is also a significant fire hazard, as the high heat can ignite the PVC or nearby flammable materials. Always wear safety goggles, avoid direct skin contact, and work in a well-ventilated area.
Take on PVC Projects with Confidence
Ungluing a PVC pipe may seem tough, but it’s entirely possible. Once you’ve got that down, gluing the PVC pipes in the way you want becomes a breeze!
By following these instructions and taking the right safety measures, you can confidently separate and replace PVC joints in your plumbing tasks. If you’re uncertain about the process, it’s always wise to consult a professional plumber for advice.
