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Speaking of threads, why do "experts" put Teflon tape on every F'n fitting that has threads ??

waterhorse

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I see this constantly in residential plumbing, automotive, etc.
 

hallett21

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In plumbing it’s so the fitting doesn’t leak....


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hallett21

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Only use teflon tape on tapered pipe fittings, never on ferrule or JIC types.

Not a plumber but what is the downside to having Teflon tape on those fittings?


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waterhorse

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Teflon tape intereferes and prevents the JIC, AN or Ferrule type from fully mating for a leak free seal. And in an automotive, marine application teflon tape on an oil or fuel line can come loose and contaminate passages.
 
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hallett21

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Teflon tape intereferes and prevents the JIC or Ferrule type from fully mating for a leak free seal.

I just grab a bigger wrench [emoji23] [emoji6]

Learned something new.


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QC22

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I rigged a boat years ago for myself. I read somewhere that you weren't supposed to use Teflon tape with gasoline fittings because you could contaminate the system. Leaked like a sieve. Spoke to some engineers where I worked and they just laughed. An absolute must.
 

LargeOrangeFont

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The "rule" is just use teflon tape on threads only. And there is no need to use it on threads that aren't made to seal.

JIC for instance uses the taper to seal. Putting teflon tape even on the threads of that fitting does nothing.
 

waterhorse

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I rigged a boat years ago for myself. I read somewhere that you weren't supposed to use Teflon tape with gasoline fittings because you could contaminate the system. Leaked like a sieve. Spoke to some engineers where I worked and they just laughed. An absolute must.
If you do use Teflon tape correctly on tapered pipe threads the first thread on the end should be left un taped so no Teflon will contaminate.
 

LargeOrangeFont

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I rigged a boat years ago for myself. I read somewhere that you weren't supposed to use Teflon tape with gasoline fittings because you could contaminate the system. Leaked like a sieve. Spoke to some engineers where I worked and they just laughed. An absolute must.

I think the real problem is what Waterhorse mentioned above. If you put the tape too far up the threads, it could cause problems. I've used it on fuel and oil systems. But I am very careful on how I apply the tape so I don't have any sticking out into the path of the fluid.
 

C-2

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What about a copper union?
 

waterhorse

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What about a copper union?
[/QUOTE
If it's clean it's good'
Edit...You could apply a small amount of Never Sieze paste to the threads for lubrication but keep the angled sealing surfaces clean.
 
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waterhorse

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Same reason why I keep finding wire nuts wrapped in 3 yards of electrical tape on houses I renovate...


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Yep, same thinking. If 6 inches is good 3 yards is better.
 

96scarab

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I always thought Teflon tape was used as a lubricant. Not for sealing purposes..
 

spectras only

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If your AN compression fitting leaks, it's garbage, probably made in China;). Lot of fancy chrome plated fuel lines for carburator setups were pure junk too, always a hit or miss to find one that didn't leak. :p
 

Wolskis

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If you need Teflon tape to keep an AN, ferrule, or other type of seated fitting from leaking then there is something wrong with your fitting.

One way you can tell a competent instrument tech from the others.
 

SoCalDave

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One of my guys uses the paste all the time on pipe fittings and gets that shit everywhere...drives my fukin nuts...
 

Rajobigguy

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Loctite PST. It's a teflon paste with a catalyzed threadlock so everything screws together nice and tight then the compound hardens for a great seal and yes it is not for sealing taper seal, flare, or gasketed fitting, if those leak they need to be replaced.
 

QC22

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If you do use Teflon tape correctly on tapered pipe threads the first thread on the end should be left un taped so no Teflon will contaminate.
100% agree. I made up an LPG line two days ago and did exactly this.
 
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Outdrive1

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Or galled threads.


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Outdrive1

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Sure.


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DLC

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I was told to use a minimum of 3 wraps with T tape, is 5 wraps to much?

Serious question—— what is to little and what is to much? If the answer is just enough so it doesn’t leak, how many wraps is that?
 

was thatguy

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Cross thread is better than loc-tite 🙄

Lol
What I mean is that an AN fitting should be easily snugged up by hand first, with the line nice and straight, unless maybe it’s a real short run.
Wrenching on an AN fitting to get it seated doesn’t necessarily mean it’s cross threaded, it can mean it isn’t seated properly.
 

was thatguy

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I was told to use a minimum of 3 wraps with T tape, is 5 wraps to much?

Serious question—— what is to little and what is to much? If the answer is just enough so it doesn’t leak, how many wraps is that?

What size pipe fitting?
Aluminum or steel?
 

SBMech

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The actual torque for fittings is FAR FAR lower than almost everyone thinks.

Over-torquing causes galling and splits banjo fittings, mushrooms and cracks flare types and generally fucks things up.

Everyone over tightens fuel, oil and brake fittings.....it's an insecurity thing because they don't actually know the spec.

I like the liquid sealant myself, it cleans up better and does a better job sealing NPT.

Like anything, almost EVERYTHING has a spec, lubed, dry, type of lube etc....RTFM or keep on guessing....
 
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LargeOrangeFont

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I was told to use a minimum of 3 wraps with T tape, is 5 wraps to much?

Serious question—— what is to little and what is to much? If the answer is just enough so it doesn’t leak, how many wraps is that?

Depends on the thickness of the tape. The $.99 stuff from Home depot is the thinnest stuff imaginable. It truly depends on the material. I usually do 5-6 wraps of the thin stuff.
 

SBMech

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20 years of talking shit to people and I am totally dyslexic when it comes to the term : Read The Fucking Manual....

I always type it as RFTM....engage brain before gear lol.....
 

500bbc

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This reminds me of Rectorseal pipe dope. Not only is it drippy and the excess gets on everything, it smells like shit and that stays on you.
Only if your applying that Rectumseal dope improperly or cross thread the install.:oops:
 
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