Loctite 55 pipe sealing tape.

[PhilipL]

I bought some of this after it being mentioned here but I am having problems.The tape is being pushed back when I tighten the fitting. It leaks on me.

Do I just use one wrap into and along the thread or what?

 

[Spectric]

What are you trying to seal?

 

[sammy.se]

Wrap it into the grooves of the thread, such that as you screw on the female part, it tightens it, rather than push it back.
Try wrapping it in each direction and you will discover which direction works.

 

[hunter27]

With normal ptfe not the one wrap wrap it on as would tighten a nut and keep it as tight as possible to get right into the threads, if you hold the roll with your finger through the hole and the tape coming off the bottom you can easily control this tension with your thumb. I usually use about 7 or 8 wraps but if the thread is slack a few more. never really used 1 wrap.

 

[PhilipL]

What are you trying to seal?

1/2 bsp fittings. Bits of a boat watermaker - just the low pressure system.

I had multiple fittings with small drips but got a ss manifold from China to simplify the system.

 

[Spectric]

You could try the PTFE tape that is used for gas fittings, it is thicker and comes on a yellow reel.

https://www.bes.co.uk/gas-thread-sealing-ptfe-tape-6963/

 

[PhilipL]

You could try the PTFE tape that is used for gas fittings, it is thicker and comes on a yellow reel.

https://www.bes.co.uk/gas-thread-sealing-ptfe-tape-6963/

Yes, an option. I'd like to find out how to use the 55 tape, though.

 

[Pedronicus]

Before using the Loctite 55 thread (best stuff since sliced bread!) you need to rough up the tops of the threads for the thread to grab on to. I used to do this with a pair of water pump pliers just squeezed enough to indent the tops of the threads. Then wrap the tape around the thread. You don't have to run it in the groove of the threads but just across the indented tops. Pull it tight as you are winding it on. Loctite is far better that PTFE tape as it can be backed off a little to get the fittings to line up if necessary. See this YT vid -

 

[Spectric]

The only Loctite product I have used on threaded pipe joints is the 557 which works well, normal tape is wide and covers the threads well but that cord looks like a bit of stringy stuff that will only sit in the bottom of the threads.

Out of curiosity I looked at what this 55 is, having never used it and found this



But it has not convinced me, old school.

 

[PhilipL]

YouTube! Random across threads it seems. And thanks for that other link, too.

 

[Pedronicus]

YouTube! Random across threads it seems. And thanks for that other link, too.

Exactly that. I have used many miles of it during my working life as it is suitable for potable water AND gas (which was my main use). Not cheap compared with PTFE tape but worth every penny!

 

[clogs]

55 tape or thread is just brill stuff ...only found it a short time ago.....
Phillip are u winding it the correct way...?
the tail of the tape needs to be wound on in the direction of the thread...
ie, u wind it on in the same direction as u wind on the fitting.....
the old flat tape,
I explain to trainee's that when u think u have enough wound on put on another 50% as it just disappears/grinds in...
I never use the flat tape flat, I make into something like the 55 stuff and wind into the thread grooves ..
normaly a double wrap starting at the back of the thread moving to the front and then back again.....
and just before u snap it off i put 2 or 3 wraps of the tape flat to tidy up the job and catch any loose ends.....
after I while u can do it in ur sleep....even for the larger fittings say one inch it only take a few seconds to get a leak free joint....
there are other products in the locktite range for high pressure stuff....I used to work with /upto 5000psi hydr oil.....
another thing, the standard of threading is now quite poor in plumbing fittings...pretty much too loose a fit with often only the last thread ortwo doing the work....
it's the cheaper fittings, even brass that are troublesome.....
Once I wrap a fitting in the first two threads I know if I need more tape due to loose threads.....
It seems to me it's only the stainless steel fitting are reliably good.....
of couse u could go back to hair n paint.....heven forbide.....hahaha...
also I quite reg have to rethread fittings...I always have in the van a full set of taps n dies.....
plus fairly often the flat flange for the sealing washeris missing or not machined properly.....
I always inspect the threads before fitting.....
it never used to be like this years ago....

 

[PhilipL]

Thanks all.

Philip

 

[johnnyb]

I use liquid ptfe esp on rads as the thread is rough and and difficult to seal. even 55 sometimes doesn't work.

 

[Bingy man]

As you wrap the tape onto the thread -anything upto 13 wraps the end of the tape should terminate in the same direction as the fitting you are threading onto the taped thread .so in short hold the roll of tape in your right hand with the tape hanging from the rear of the spool , with the fitting or pipe end in your left hand place the tape on the pipe and keeping slight tension on the tape start wrapping clockwise. After a few turns it will hold itself and you can continue wrapping. Depending on the length of the pipe overlap it slightly and wrap continually until several wraps have been completed. 6 or 7 maybe enough but I usually go to 13 and see how it feels when the fitting is tightened up . Don’t bother with the gas ptfe as it’s to thick for water pipes . The hole in the ptfe spool is for your finger . Practice a few turns and it becomes easier. I’ll get my son to video me and I’ll attempt a demo and send you a pm . Hope it helps.

 

[Dave Moore]

I bought some of this after it being mentioned here but I am having problems.The tape is being pushed back when I tighten the fitting. It leaks on me.

Do I just use one wrap into and along the thread or what?

You wrap it into the thread. If you look on the instructions it tells you how many wraps for the size of pipe. Finish the wrapping at the end of the pipe, not the back so that the end is taken into the thread at the start. Once the bond sets its difficult to remove as it bonds but it should seal immediately.

 

[Dave Moore]

The only Loctite product I have used on threaded pipe joints is the 557 which works well, normal tape is wide and covers the threads well but that cord looks like a bit of stringy stuff that will only sit in the bottom of the threads.

Out of curiosity I looked at what this 55 is, having never used it and found this



But it has not convinced me, old school.

The problem with the modern ptfe tapes are that they are so thin now that the threads sometimes cut through them allowing leaks. Stainless steel threads are renowned for this in my experience during the last 50 yrs. I remember as an apprentice that Ptfe tape used to be like the gas seal tape thickness and has gradually got thinner. I find it pretty useless on compressed air apart from instrument fittings where it might want removing again. The guy on the video puts the Loctite 55 on randomly but we have found it’s better putting it into the thread and if my memory serves me well is how it’s meant to be used.

 

[Davyc]

@Dave Moore
Hi there. What do you recommend for airline fittings? I have a few chineseum airline fittings in my shed that are not very...airtight....I am afraid to put too many wraps of tape on some of them in case they split the fittings...
Cheers.

 

[Tony51]

First wrap tape around a nail. Then apply to the thread.. It's a lot easier that way to control the tape.
Tony

 

[Pedronicus]

@Dave Moore
Hi there. What do you recommend for airline fittings? I have a few chineseum airline fittings in my shed that are not very...airtight....I am afraid to put too many wraps of tape on some of them in case they split the fittings...
Cheers.

This would be my choice assuming you are using steel pipe with taper threads.