by Lee Russell

Created on: February 05, 2010

Teflon Tape History

Polytetrafluoroethylene (or PTFE) was developed by the DuPont research laboratories in 1938. In 1945, DuPont began marketing products containing the substance and mercifully named it "Teflon".

Teflon tape is widely used to seal threaded connections in plumbing and other fittings. It is very slippery and is chemically non-reactive, two properties that are very useful for plumbing. It reduces friction, allowing pipes to tighten smoothly in fittings; and it won’t corrode when exposed to water, making threaded joints easier to take apart.

Teflon tape replaces pipe dope as the tool of choice when joining threaded connections. It is cheap, easy to use, and leaves no mess or residue. Applying the tape is a simple skill to learn, and will come in handy for many plumbing chores. Teflon tape is sold in rolls and can be found at any home improvement center or plumbing supply store.

Using Teflon Tape

Prepare the parts to be joined by cleaning them thoroughly. Clean pipe threads using a brass brush, running it along the direction of the thread grooves. Old Teflon tape will come off in shredded ribbons, while old pipe joint compound or "dope" will probably be caked into the grooves. Keep scrubbing until the bare metal is exposed.

Start the tape at the first threads at the end of the pipe. Hold the end of the tape in line with the threads and wind in a clockwise direction, as you look at the end. This will prevent the layers from unwinding when the pipe is screwed into the fitting. The first wrap or two will hold the starting end of the tape in place.

Keep gentle tension on the tape as you wind, to help it seat into the thread grooves. Try to keep the Teflon flat and even, with no wrinkles or twists.

Overlap each turn by half the width of the tape. Continue wrapping until all of the threaded section is covered with Teflon tape. Pull firmly on the roll until the tape breaks, then smooth the tail around the pipe.

Screw the end of the pipe into the fitting, and tighten by hand as much as possible. Finish tightening using a pipe wrench on plain pipe, or an adjustable wrench on fittings with flats.

Turn the water on and check for leaks. If any are found, tighten the joint another quarter turn or so.

Other Uses

Teflon tape can also be used simply for its friction-reducing properties. Compression fittings used for flexible copper line do not need their threads sealed; the seal is made inside the fitting by a compression ferrule. Many plumbers use a drop of oil to lube the threads to make tightening up the joint easier. Instead of using oil, a wrap or two of Teflon tape also makes the joint easy to tighten up, and will still be there if the connection ever has to be taken apart.

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