Is there good and bad PTFE tape?

[Ian H]

I had a right pain in the arse sealing a 3/4 make thread into a shower. It leaked 3 times. Each time it had a tiny leak that would pass out a single drop of water over 5 days that wasn't heavy enough to fall off the fitting.

I cured it by wrapping the fitting about 25 times which I thought was excessive. It will be behind a plastered wall but I'm a bit paranoid about hiding it even though it isn't leaking now.

Is 25wraps normal, is my PTFE crap or is it just me? Does the PTFE make its seal on the thread or just outside it?

This is it when I took off the last leak

This is the PTFE

That's how much I wrapped in on my final attempt.

That's it in place and not leaking

 

[durhamplumber]

yes 25 turns is excessive.I would use less ptfe plus boss white.Is the fitting bottoming out in the female part?..are the parts designed to fit?..not expert on parallel /tapered threads etc but that could be an issue.is the fitting designed to have a fibre washer at the bottom?..1 drip a week is bizarre!!!!

 

[Madrab]

Use gas tape, I find it's much better that normal PTFE as it's thicker.

 

[Ian H]

No, it doesn't bottom out. They are both 3/4 thread but the shower is from one place and the fittings from another.

I don't think it's designed for a fibre washer because there is a retaining wire on the showers non return valve which would touch a washer.

Second time I did it I could see tiny balls of water forming on the PTFE (as if it was squeezing through) as soon as I turned the water back on.

 

[durhamplumber]

maybe one part is parallel and the other is tapered..no good using thicker gas tape...if 25 turns don't work it aint ever going to work....boss/Hawk white...best bet..possibly hair line crack if it has been over tightened... or put washer in bottom to make sure not bottoming out ..and just might help

 

[durhamplumber]

from your photo...is the elbow one fitting or two??...thin line of ptfe looks like it is an elbow going into a reducer??...might be seeing things

 

[Ian H]

It sealed after 25 wraps and hasn't dropped or formed any moisture since.

I've got some radiator tails to do and I don't want the same trouble with those, I'm wondering if the shower is cheap ****e because it came from Better Bathrooms.

 

[durhamplumber]

cheap rubbish fittings are a nightmare..Rad tails i go for 14 turns of ptfe and rarely have problems..

 

[Ian H]

from your photo...is the elbow one fitting or two??...thin line of ptfe looks like it is an elbow going into a reducer??...might be seeing things

Yes, it's a 15x1/2 bend with a 1/2 to 3/4 bush. I used a 15x3/4 (all 1 fitting) straight on the other side and that was the same.

Fittings were from my local plumbers merchants. This is the shower:

https://www.betterbathrooms.com/sho...ealed-dual-control-shower-valve-with-diverter

 

[just pumps]

No offence meant however is the tape being applied in the correct rotation.
Looking at the last photo of the assembled joint makes me wonder this.

 

[Ian H]

Yes, I wrapped it so the last flap was being pulled into the thread rather than being pushed into it if you know what I mean.

 

[Hot&Cold]

I'm wondering if the shower is cheap ****e

Ian,its cheap compared to a known brand like bristan (which comes with 15mm compression fittings attached as standard).

Fittings into your valve can be bothersome,have only fitted a few that customers had supplied. Only ever used straight couplers with decent flanges.

ptfe at least 20 turns adjacent to the flange,leaving the first 4 or 5 male threads ptfe less so the thread pulls the coupler flange tight against the shower mating surface.Had to file rough bits off of one shower valve mating surfaces once,the china man forgot to do it at the factory .

I avoid elbows into them shower valves,use elbows after.

Ps a lot of people have leaking shower fittings inside their cavity wall.Some installers have been known to leave a very small drip (leak).Some installers dont check to much pure diy.

 

[Ian H]

I would have put a straight on but there is a shelf built into the wall just to the side of it.

Don't tell anyone but I forgot that last night and pulled the plasterboard off the back of the tiles

 

[Ian H]

ptfe at least 20 turns adjacent to the flange,leaving the first 4 or 5 male threads ptfe less so the thread pulls the coupler flange tight against the shower mating surface.

I bet that's where I went wrong!! I was putting an equal amount on all the threads thinking it made it seal between the male and female threads rather than on the face.

 

[cross thread]

buy some locktite 55