Flooding the Industry with Failures, an Investigation into Thread Sealants

Thread sealants come in two major varieties: pipe “dope” and thread tape generally comprised of PTFE (Teflon). Both of these products serve a similar function, but are recommended for differing applications, lifespans, and materials of threaded connections.

Instructions for thread sealant products can be vague, specifically when describing potential interactions between multiple sealing products and the quantities to use. In some cases, the instructions identify a single thread sealant and clarify the quantity needed. In other cases, the instructions specify multiple thread sealants while neglecting to specify the recommended amount of either. As a result, plumbers, handy homeowners, and other users have their own opinions about the best recipe for success when sealing threaded connections. Some pervasive wisdom implies that using both Teflon tape and pipe dope on a single junction yields the best results. When, if ever, is the use of multiple sealing products permissible?

In this work, we assembled threaded junctions with zero, one, and two sealing products applied. Then the performance of the junction was assessed. Is doubling up a guarantee for success, or is it flooding the industry with failures?