Teflon tape or pipe dope can be used to create a seal on black iron pipe. Tim Carter of AsktheBuilder.com demonstrates how to do the job right and shares some helpful tips. This black iron pipe is used to transport natural gas to your furnace, water heate

Video Transcription

Rack iron pipe, there is a lot of it around the greater cincinnati area and I will tell you why, we use it a lot to supply natural gas to furnaces and water heaters and even maybe even your stove. And of course it has treated fittings and you need to seal those when you put the tube parts together, otherwise, you are going to have natural gas leaks. There are two different ways to do it, one way to seal pipe joints is to go ahead and Teflon tape, it is a simple ribbon of Teflon, I like to tear of a piece about ten inches long and wrap it around the end of male piece of pipe making sure that as you look down at the end of the pipe, you wrap it in a clockwise fashion, that is extremely important. Once the Teflon is on the end of the pipe, you are ready to go ahead and put the pipe into the fitting. The reason you need to use a pipe sealant in the first place is because the treads that machined on to the fitting and on to the actual pipe are not perfect and there is a gap between them even when they are tight that it can allow natural gas or any liquid to escape. And of course, once you get it hand tight, you have to use pipe wrenches to go the rest of the distance. The other method to see a block iron pipe joints is to use pipe dope. Call me old fashion, call me an old pipe dope I do not care but this a really neat product, it is the consistency of possibly mashed potatoes and you just paint this on the male treads of the pipe before you put it in the fitting. Two final pointers, remember, no pipe dope on the inside of the fittings and you do not put Teflon tape in there, it is only on the ends of the pipe. And remember, once you are hand tight, you have got to complete a couple of rotations, maybe just one with pipe wrenches so that the pipes do not leak. I am Tim Carter, ask the builder. If you want to discover more home improvement tips, go to askthebuilder.com