WELCOME TO RIVER DAVES PLACE

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

waterhorse

Well-Known Member
Joined
Oct 2, 2008
Messages
2,268
Reaction score
858
I see this constantly in residential plumbing, automotive, etc.
 

hallett21

Well-Known Member
Joined
Nov 9, 2010
Messages
7,882
Reaction score
4,191
In plumbing it’s so the fitting doesn’t leak....


Sent from my iPhone using Tapatalk
 

hallett21

Well-Known Member
Joined
Nov 9, 2010
Messages
7,882
Reaction score
4,191
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?


Sent from my iPhone using Tapatalk
 

waterhorse

Well-Known Member
Joined
Oct 2, 2008
Messages
2,268
Reaction score
858
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.
 
Last edited:

QC22

Landing Loser
Joined
May 14, 2018
Messages
547
Reaction score
636
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

Steers With Throttle
Joined
Sep 4, 2015
Messages
20,797
Reaction score
25,083
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

Well-Known Member
Joined
Oct 2, 2008
Messages
2,268
Reaction score
858
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

Steers With Throttle
Joined
Sep 4, 2015
Messages
20,797
Reaction score
25,083
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

Well-Known Member
Joined
Sep 26, 2007
Messages
9,051
Reaction score
3,417
What about a copper union?
 

waterhorse

Well-Known Member
Joined
Oct 2, 2008
Messages
2,268
Reaction score
858
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.
 
Last edited:

waterhorse

Well-Known Member
Joined
Oct 2, 2008
Messages
2,268
Reaction score
858
Same reason why I keep finding wire nuts wrapped in 3 yards of electrical tape on houses I renovate...


Sent from my iPhone using Tapatalk Pro
Yep, same thinking. If 6 inches is good 3 yards is better.
 

96scarab

Well-Known Member
Joined
Jan 11, 2014
Messages
183
Reaction score
251
I always thought Teflon tape was used as a lubricant. Not for sealing purposes..
 

spectras only

Well-Known Member
Joined
Sep 20, 2007
Messages
10,189
Reaction score
6,022
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

Well-Known Member
Joined
Jan 21, 2008
Messages
360
Reaction score
403
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

Well-Known Member
Joined
Jul 1, 2011
Messages
6,879
Reaction score
10,769
One of my guys uses the paste all the time on pipe fittings and gets that shit everywhere...drives my fukin nuts...
 

Rajobigguy

Well-Known Member
Joined
Aug 21, 2015
Messages
2,252
Reaction score
3,427
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

Landing Loser
Joined
May 14, 2018
Messages
547
Reaction score
636
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.
 
Last edited:

DLC

Well-Known Member
Joined
Jan 18, 2013
Messages
2,870
Reaction score
2,558
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

living in a cage of fear
Joined
Apr 28, 2008
Messages
32,814
Reaction score
38,338
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

living in a cage of fear
Joined
Apr 28, 2008
Messages
32,814
Reaction score
38,338
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

Fixes Broken Stuff
Joined
Jul 25, 2012
Messages
7,724
Reaction score
10,148
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....
 
Last edited:

LargeOrangeFont

Steers With Throttle
Joined
Sep 4, 2015
Messages
20,797
Reaction score
25,083
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

Fixes Broken Stuff
Joined
Jul 25, 2012
Messages
7,724
Reaction score
10,148
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

Well-Known Member
Joined
Oct 16, 2007
Messages
20,024
Reaction score
23,159
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:
 
Top