Whether you made a mistake or you're replacing an old fixture, you need to unglue PVC pipe. This is impossible. Nothing will dissolve the solvent between the pieces of PVC [source: This Old House]. Don't worry; there's a solution. Follow these tips to learn what to do when you want to unglue PVC pipe.

Here's what you'll need:

  • Hacksaw
  • Purple primer
  • Clear PVC cement
  • A new fitting and coupling

Here's what to do:

  1. Cut out the problem joint Use a hacksaw to cut the PVC pipe flush along the fitting of the joint that you wish you could unglue [source: This Old House].
  2. Get a new fitting and coupling Find a new fitting that satisfies your new needs. Find a coupling that matches the old fitting you didn't cut out and the new one you're adding [source: This Old House].
  3. Prime the PVC Apply a thin layer of purple primer to the ends of your PVC fittings. Also apply the primer to the inside of the coupling. Let the primer dry for a few minutes [source: Maki].
  4. Glue the new joint together After the primer is dry, coat the primed areas of the pipes and coupling with clear PVC cement. Some multi-purpose cement glues aren't approved for all pipe uses, so make sure you're using a PVC-specific type. Push the pipe into the coupling while turning it a quarter turn. Make sure the fittings don't pop out before the adhesive hardens. If possible, wipe away any excess glue from the outside of the pipe before it dries [source: Maki].