# when to use teflon tape?



## noone (May 4, 2011)

Dumb question-

I don't need to use teflon tape on a fitting that has a rubber washer in it correct? I'm hooking up a dishwasher and just wanted to confirm. The braided supply line and the garden hose adapter all have washers on them.

I think the only time you use teflon is when there is not a ferrule or washer when something screws into something without a gasket or seal.....

Thanks again.


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## joecaption (Nov 30, 2011)

All the items you mentioned have straight threads so no sealer is needed.
Only need to tape or dope tapered threads.
All pipe threads are tapered.


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## ben's plumbing (Oct 6, 2011)

noone said:


> Dumb question-
> 
> I don't need to use teflon tape on a fitting that has a rubber washer in it correct? I'm hooking up a dishwasher and just wanted to confirm. The braided supply line and the garden hose adapter all have washers on them.
> 
> ...


 yep your right....no tape needed..ben sr


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## tylernt (Jul 5, 2012)

Agreed, tape is not necessary on quality straight thread fittings. Just snug them up 1/8 or 1/4 turn with pliers after hand tight.

However, for cheap thin metal garden hose connections, I always seem to get a dribble unless I use tape. The tape in that case is not acting to seal the threads, but rather is simply a lubricant so I can get a higher torque so the washer can do it's job.

I also buy spare garden hose washers by the 10 pack... have to change 'em out every year or two. I hate leaky garden hoses.


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## noone (May 4, 2011)

tylernt said:


> Agreed, tape is not necessary on quality straight thread fittings. Just snug them up 1/8 or 1/4 turn with pliers after hand tight.
> 
> However, for cheap thin metal garden hose connections, I always seem to get a dribble unless I use tape. The tape in that case is not acting to seal the threads, but rather is simply a lubricant so I can get a higher torque so the washer can do it's job.
> 
> I also buy spare garden hose washers by the 10 pack... have to change 'em out every year or two. I hate leaky garden hoses.


Say again?????

You have to change out the washer on a garden hose fitting on a dishwasher every two years???

That sounds absurd. Say it isn't so......

I can't be worrying about my dishwasher leaking all over my hardwood floors every two years....


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## tylernt (Jul 5, 2012)

No, I go through a lot of washers on hoses used outside on the lawn and garden. 

The threads on dish and clothes-washers are normally called "hose threads". They work fine, untouched, for decades. But while the same thread form is used on exterior hoses, the exterior hoses never seem to seal as well for me. Maybe because I don't have pliers on me outside...


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## noone (May 4, 2011)

Whew! 

:laughing:


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## ddawg16 (Aug 15, 2011)

FYI....teflon tape is not intended to seal....it's primary purpose is to reduce the friction of threads so you can get more turns on the pipe connection.

Now....with that said....there is a 'small' amount of sealing provided by the tape....but it's pretty small and you can't depend on it.

But....nothing wrong with wraping the male end with tape if your having trouble getting it tight. The tape will reduce friction and let you get a little more twist in the fitting....


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## TheEplumber (Jul 20, 2010)

noone said:


> Whew!
> 
> :laughing:


:laughing::laughing:
OK- now my 2 cents- I simply use a little PTFE dope to relieve the friction. I use it on compression fittings, ground joint unions, trap nuts, etc. A little dab 'ol do ya


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## paintdrying (Jul 13, 2012)

*Gas line unions*

I use dope on many type threads, I use pipe dope on the inside of flared fittings. I use it on gas pipe unions, especially the outside threads. I always thought the tape sealed and the dope lubed. Some places will not allow tape on a gas pipe line. Not sure anything about that stainless steel stuff that came out in the late 80's. Those braided steel water lines I use nothing on. Those pull out faucets and fancy shower heads on a hose I use tape on those cheap plastic threaded connects because it seems to keep things from working loose. Some compression type unions I use locktite on the threads but that would not apply on this from i do not believe. As for the dishwasher elbows I use nothing on. I do ask myself why the elbows do not come with the dishwasher and why it is not possible to by pass the use of an elbow when using a 3/8 copper line.


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## noone (May 4, 2011)

I always thought tape created "more" friction and thus a tighter seal.

When you guys screw in nipples for shower hoses and bath spouts and the like, do you use teflon tape and rector seal or just one or the other?

I'd prefer to just use just rector seal. It's easier to screw in with that stuff on vs both.


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## paintdrying (Jul 13, 2012)

I use tape on bath spouts and shower head arms. Rector seal is good stuff. For me it depends if i am doing exposed trim or something buried in a wall.


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