Weeping compression fittings

[stratplus]

How is it that when something is worked on in the area that compression fittings are fitted, the compression start to weep even though they haven't been touched and when you try to nip them up they are solid?

 

[bigads28]

I was at one last job yesterday under a floor that managed to work itself slack fully a turn. It hadn't been touched since the day it went in.

 

[stratplus]

I was at one last job yesterday under a floor that managed to work itself slack fully a turn. It hadn't been touched since the day it went in.

Went to one yesterday, bg had changed some kitchen taps and an existing comp elbow had started to weep. Tried to nip it up and was solid couldn't turn it at all. Had to re-make with sone jointing compound.

Thing is you see loads of compression fittings behind kitchen cupboards which are inaccessible. If they leak due to you working on another joint it becomes a problem. End feed everytime for me.

 

[lame plumber]

only reason a comp joint will leak is because youve disturbed it.

 

[Ermintrude]

Just sodder them compression on. It works [emoji12]

 

[dom brennan]

i always tighten the olive on the pipe then undo it and wrap some PTFE around then tighten it back up. it takes a bit longer but it saves it leaking in a few years time

 

[Ermintrude]

Use a carrier bag it's cheaper and looks less DIY

 

[lame plumber]

i always tighten the olive on the pipe then undo it and wrap some PTFE around then tighten it back up. it takes a bit longer but it saves it leaking in a few years time

the fact you under it then wrap ptfe round it is more likely to damage the joint and cause it to leak. If u must, wipe a bit of jonting compound on tighten it up and then squeeze another 1/2 turn max.

if high pressure fuel lines rely on an olive joint with no ptfe or gunk why are plumbers bothering to faff around and and not make joints as they are designed to be made.

 

[dom brennan]

its how I've been taught and never had one leak yet.

 

[stratplus]

the fact you under it then wrap ptfe round it is more likely to damage the joint and cause it to leak. If u must, wipe a bit of jonting compound on tighten it up and then squeeze another 1/2 turn max.

if high pressure fuel lines rely on an olive joint with no ptfe or gunk why are plumbers bothering to faff around and and not make joints as they are designed to be made.

So what do you do when there is a weep and the joint is already solid and won't tighten anymore? You've got no choice but to undo it and add some jointing compound or ptfe.
Out of interest:
Ptfe or jointing compound?

 

[CXR100]

jointing compound!! I put it on every compression joint, never have any problems with them . don't bother with ptfe , only on threads!

 

[Best]

Compression joints will tend to weep very slightly - particularily cheap fittings or poorly made or designed olives & copper olives on hot pipes. The weeps are invisible normally & are only evident if you see a bit of a stain pipe & seized nuts are proof the fitting has been weeping. Soldered fittings for me everywhere I can & any compression fitting I use Jet Lube paste which guarantees a sealed joint.

 

[tamz]

Just sodder them compression on. It works [emoji12]

Aye but is it an "appropriate fitting"
Might be for me if i loose the nut :lol:

 

[Ermintrude]

Never done it. Not on a 3/4 rad valve with a bit of tube

 

[TerryH]

I always wipe a smear of jointing compound between the olive and the fitting on the bevel edged margin. To my way of thinking it will compress better and seal any inconsistencies on the joint. PTFE is a second best, the water's already past the olive by then :disappointed:.... and it looks neater too, no white stripe!
Regards, TerryH

 

[AWheating]

original fitting prob over tightend when fitted. Too many cheap compression fittings around now, conex or yorkshire if your not paying

 

[stratplus]

original fitting prob over tightend when fitted. Too many cheap compression fittings around now, conex or yorkshire if your not paying

The one I went to has prob been in 30 years.

 

[Sparkgap]

Twenty+ years ago did some pipework replacement in an OPH which had been piped in hard copper and brazed because that was all they had during the copper shortage in the 70s. Soon as you did one joint the next joint would start leaking. Sort that and the next one on would leak. Turned a two day job into three weeks :banghead: