Woodnet Forums

I recently replaced shutoff valves in the guest bathroom using teflon tape.  No matter how tight I made the valves they leaked at the junction.

I removed them and used a wire brush on a drill to make sure that the threads were perfectly clean.  Then I used the teflon tape and brand new valves and they leaked again.

I recently had my furnace serviced (under a service contract) and I asked the service man about replacing some of the bleeder screws.  I bought new bleeder screw bodies and I needed to know how to relieve the pressure from the system while I was working.  I also asked if I should use teflon tape and he said, "Use plumbers' grease; it's messy but you are less likely to have any leaks."

So I went to Home Depot, where they only sell a high-tech version of plumbers' grease ("With the strength of Kevlar").  You can see and feel the chopped fibers. 

I rubbed the grease into the male threads so that they were all completely filled with grease.  I screwed on the valves (which went on much more easily and screwed in further).  I turned on the water and not a drop has leaked since.

So if you ever have problems with a screw-fit pipe joint I recommend you try plumbers' grease before over-tightening the joint.

Same here.  My success with Teflon tape is poor on metal piping; never a problem with pipe dope. 

Note, you can't use regular pipe dope on threads in plastic parts because the petroleum in it will soften the plastic over time, or so I am told.  However, they make a Teflon pipe dope that contains no petroleum which is compatible.  For whatever reason, I've never had a problem withe Teflon tape on plastic threads, however, so that's what I normally use, and the only application where I use it. 

John

that's interesting.  Not a big fan of teflon tape.

I have done lots of hydraulic plumbing, which is an order of magnitude more pressure than water (3000psi).  For that reason, pipe threads are not used a lot, but inevitably there is something that has pipe threads on it.  I use a loctite product that is safe for the expensive bits, unlike teflon tape, which can get stuck.  I thought about getting that for home, but it's a bit much $

Rectorseal #5  pipe dope is good on plastic as well as the metal connections.   Is good with gas also.    Available at big boxes.     To me plumbers grease is made for faucets and parts like that. While by lubricating threads you can tighten them tighter for a better seal, why not use a product made for sealing which also lubricates. Roly

+1 Teflon tape is nigh on worthless.

I've spent my entire career in and around hydraulics systems.  You don't want teflon tape anywhere near a hydraulic system.  All it takes is one little piece of the stuff to clog up an oriface or something.  Yes, we always used the Loctite thread locker.

For home plumbing, you want this stuff or something similar:



good luck,

I used the Oatey stuff:  http://www.homedepot.com/catalog/product...0_1000.jpg

They say is is OK for air pressure to 3,000 pounds.  I used it for both the hot water and cold water outlets.  I'm sold.  I went through three sets of valves (the previous ones are almost certainly still good, but I wanted to make this my best shot so I used new ones), and this is the only stuff that got the job done.

"Plumbers Grease," implies a different product than pipe thread sealant. Sometimes combining teflon tape with a top coat of plumbers pipe sealant provides the best results on IP threads.

(11-21-2016, 02:30 PM)doobes Wrote: [ -> ]+1 Teflon tape is nigh on worthless.

I've spent my entire career in and around hydraulics systems.  You don't want teflon tape anywhere near a hydraulic system.  All it takes is one little piece of the stuff to clog up an oriface or something.  Yes, we always used the Loctite thread locker.

For home plumbing, you want this stuff or something similar:



good luck,

 This type is all I ever use now.

I never noticed that stuff, going to get some. HD thanks ya'll

I sometimes work on a machine tool that has hydraulic oil ways. There are some pressure regulating orifices that are forever getting clogged with teflon tape. So much fun.

my FIL, retired longtime contractor, worked with a long time plumber that always used tape and pipe dope.  Plumber said it takes him a moment more to use both but he's never been called back because of a leaking threaded joint.