When Teflon tape is wrapped around plastic male threads it adds to the strain and tensile stress. Teflon paste and pipe dope, just like Teflon tape, make threaded joints slippery. Their use on PVC fittings can be an invitation to over-torque. When working with threaded plastic fittings do use a proper sealant.Click to see full answer. In this way, what is the best thread sealant for PVC?When assembling threaded PVC fittings, a sealing compound that is non-hardening is the best. Recommended good practice is to use a thread sealant (not a thread lubricant) to assemble the joint to finger tight plus one and one-half (1½) turns, two turns at the most.Secondly, should I use Teflon tape on plastic pipe threads? Plastic fittings do not need this lubrication. When Teflon tape is wrapped around plastic male threads it adds to the strain and tensile stress. Teflon paste and pipe dope, just like Teflon tape, make threaded joints slippery. Their use on PVC fittings can be an invitation to over-torque. Also to know, how do you thread a pipe tape? Correct Use Clean the male threads at the end of the pipe with a clean rag. Place the end of the plumber’s tape on the second thread from the end of the pipe and hold it in place with a finger or thumb. Begin wrapping the tape around the pipe in the opposite direction to the direction the pipe will be turned. Is pipe thread sealant better than Teflon tape?It works with all types of pipe and fitting materials, and it produces a strong seal. Pipe dope is generally stronger seal than Teflon tape, which is why plumbers and other professionals use it rather than tape for seals that are permanent.