Get a reliable seal for NPT fittings with UKOKE PTFE pipe thread sealant cord. Designed for convenient application across suitable plumbing and pipe-thread connections.
https://ukoke.com/products/ukoke-394-pipe-thread-sealant-cord-for-npt-fittings-1-8-4-ptfe-tape-upgrade-for-us-plumbing-gas-hvac-1
