What’s the Difference: Joint Sealing with Teflon Tape and Pipe Dope
The success of any plumbing project hinges largely on making sure that joints don’t leak. Threaded connections between metal or plastic parts can be particularly problematic. Teflon tape and pipe joint compound (often called pipe dope) are two options for filling voids between threads and making the joints leakproof. These products also help preventing metal parts from rusting together. There’s no real benefit, by the way, of using pipe dope in addition to Teflon tape.
Pipe dope is easier to apply
Pipe dope is available in containers as small as 1 fl. oz. and as large as 32 fl. oz. To apply pipe dope to the male end of a threaded pipe or fitting, swab the threads with the supplied brush that’s been loaded with compound. Although using pipe dope can be a bit messier than sealing with Teflon tape, it’s faster. Similar to Teflon tape, pipe dope comes in versions designed for water lines and for gas lines. Read packages carefully because all dope cannot be used on plastics.
Approximate cost: $3 per 8-oz. can
Teflon tape is less messy
Teflon tape, which is available in 1⁄2-in. to 1-in. widths, comes in high- and low-density versions. While Teflon tape isn’t as messy as pipe dope, it can be more difficult to apply properly. If wrapped incorrectly (in a counterclockwise direction), the tape can ball up as components are tightened, ruining the seal. Many pros complain about the quality of low-density tape, which is less expensive. More low-density tape is required to seal a joint properly because it compresses more than high-density tape. Low-density tape also tends to shred easily. A strand of tape that finds its way into a plumbing line can cause problems.
Approximate cost: Starting at $1.50 per roll
More on Plumbing:
How To Connect PVC Pipe – Learn how to prepare plastic pipe fittings, apply primer and cement, and make the connection between the two parts.
How to Make Basic PEX Connections – PEX components are user-friendly, leave water systems immediately ready for inspection, and don’t require glue joints to set up. Learn how PEX connections can make your next plumbing job easier.
The Right Way to Join Plastic Pipe – Both PVC and ABS plastic pipe are so easy to work with that they’re often slapped together without much thought. Are you sure you’re joining them correctly?