Sealing bib tap threads

geraldthehamster · 21 May 2015

Some time back I fitted new bib taps, with upstands, in my kitchen. The taps screw horizontally into the upstands. Anyone know how I can stop the cold tap from weeping at the join?

So far I've tried PTFE in the threads. I've tried clear sanitary silicone in the threads and as a washer on the mating surface (allowed to go off). I've tried Fernox LS-X in the threads and on the mating surfaces. Not at the same time, you understand. None has been watertight.

Locktite 55?

Cheers
Richard

Madrab · 21 May 2015

Is there a flat face where the tap mates to the upstand? If so a 1/2" rubber washer could be used.
If it's flush then it should be a tapered thread and you may want to try Gas PTFE, it's thicker than normal tape and may be more suitable.
Has it always leaked? You may have compromised the threads by using too much tape previously.

geraldthehamster · 21 May 2015

Madrab said:
Is there a flat face where the tap mates to the upstand? If so a 1/2" rubber washer could be used.
If it's flush then it should be a tapered thread and you may want to try Gas PTFE, it's thicker than normal tape and may be more suitable.
Has it always leaked? You may have compromised the threads by using too much tape previously.

Hello and thanks.

Interesting point about the washer. I was able to seal the leaking hot tap by using a washer on the flat face, because without it the tap isn't upright when screwed fully home into the upstand. However, the cold tap lands upright without a washer, but lands askew with one. So I can't use a washer. I'll try gas PTFE though.

It's always leaked - I put the taps in a month or so ago and have had them apart three times - twice to try silicone and once the Fernox.

The first time I did use about a dozen turns of PTFE, and I did apply it in the right direction

Cheers
Richard

Nige F · 21 May 2015

Hemp and boss white

stuff the alleged breeding of bacteria

. The tap will stay where you put it and there are millions of connections like it in use.

geraldthehamster · 21 May 2015

Given that I'm unlikely to want to remove the tap from the upstand, would it be the height of stupidity to fix it with Araldite or a two-part resin?

Can you tell I'm not a plumber?

Cheers
Richard

Madrab · 21 May 2015

Lol...let me tell you, seen worse.

Trouble is if it doesn't seal first time, entirely likely with epoxy on metal, then you can have a mare of a time cleaning it to try again. An epoxy putty can sometimes be used but again a nightmare if it doesn't seal 1st time.

geraldthehamster · 21 May 2015

Madrab said:
Lol...let me tell you, seen worse.

Trouble is if it doesn't seal first time, entirely likely with epoxy on metal, then you can have a mare of a time cleaning it to try again. An epoxy putty can sometimes be used but again a nightmare if it doesn't seal 1st time.

I won't do that.

In theory the gas PTFE ought to work. The past failure with PTFE is probably operator error.

What about Locktite 55, which I saw mentioned when I searched the forum?

Cheers
Richard

flameport · 21 May 2015

Get the gas PTFE.
Wind it on the the thread in a taper - i.e. overlap it more as you get to the body of the tap, so that as you screw the tap in, there is more tape there to seal.

Do not use epoxy or similar - you will regret it.

geraldthehamster · 21 May 2015

flameport said:
Get the gas PTFE.
Wind it on the the thread in a taper - i.e. overlap it more as you get to the body of the tap, so that as you screw the tap in, there is more tape there to seal.

Do not use epoxy or similar - you will regret it.

Thanks. I've noticed the Everbuild gas PTFE is "One Wrap" - should I ignore that and wind lots on anyway?

Cheers
Richard

Madrab · 21 May 2015

No, don't wrap on lots, you can have the scenario were you actually break the female fitting trying to tighten it too much. You should be using just enough whereby you aren't actually needing to tighten the fitting right up to the end of the thread to make it watertight. Too tight and it wont seal as it strips all the PTFE off the thread.
It's hard to describe how tight it should feel, it's an experience thing if you know what I mean, how loose it feels without tape etc.
Start off with 3 or four turns and see how you go, would be my advice.

geraldthehamster · 21 May 2015

Madrab said:
No, don't wrap on lots, you can have the scenario were you actually break the female fitting trying to tighten it too much. You should be using just enough whereby you aren't actually needing to tighten the fitting right up to the end of the thread to make it watertight. Too tight and it wont seal as it strips all the PTFE off the thread.
It's hard to describe how tight it should feel, it's an experience thing if you know what I mean, how loose it feels without tape etc.
Start off with 3 or four turns and see how you go, would be my advice.

OK, thanks. The only slight issue with that is that unless I tighten it to the end of the thread, the tap isn't upright.

these are the taps:

http://www.bristandepot.co.uk/plumbing/RSBIBC.jpg

Cheers
Richard

Madrab · 21 May 2015

Sorry didn't mean to confuse, what I meant by that is that it shouldn't need to be tightened fully to become watertight, not that you then couldn't tighten fully to line up.

oilboffin · 21 May 2015

I'm with nige boss white and hemp

geraldthehamster · 23 May 2015

I've just re-done the tap with gas PTFE, and so far it's not leaking. Gas PTFE may be my new favourite thing

Cheers
Richard

oilboffin · 23 May 2015

If not ptfe and heldite

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Sealing bib tap threads

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