after a rather more eventful weekend than i was hoping for, i'm hoping
somebody can explain this....

i finished plumbing in everything in my new bathroom a couple of weeks
ago. no real problems and all went quite well. so, i was a bit
surprised to be woken at 1am on saturday to the sound of water running
and a hysterical girlfriend. it appears that one of the compression
joints has spontaneously exploded, allowing mains pressure water to go
everywhere. fortunately no real damage done, just a lot of mopping up
to do downstairs.

the bit i don't understand is why this joint went so suddenly. here's
the facts :

1. the pipe had just slipped straight out leaving the olive in the
service valve that the pipe had escaped from.
2. the joint hasn't leaked at all in the last 2 weeks.
3. the pipe was running from a service valve horizontally about 4"
across then going to a flexi-hose which connects vertically to the
adapters which go up to the mixer tap.
4. the pipe wasn't supported by pipe clips, although it's a short run
and hardly moves at all anyway.
5. i'd put a couple of wraps of PTFE tape over the olive as i'd been
advised that this can help stop small leaks (was this my downfall?)
6. all the other compression joints i've made are absolutely fine and
have been for 2 weeks.

i'd quite like to understand why this joint has failed so spectacularly
before i go trying to fix it.

thanks
dan

Redeye wrote:

5. i'd put a couple of wraps of PTFE tape over the olive as i'd been
advised that this can help stop small leaks (was this my downfall?)


IANAP
Best to remove all tape, provided the fittings are clean, unscratched
and undamaged. Tighten until the olive just grips the pipe. Add an
extra 1/6 turn to compress the olive.
No doubt proper plumbers will disagree.

john2

Redeye wrote:
after a rather more eventful weekend than i was hoping for, i'm hoping
somebody can explain this....

i finished plumbing in everything in my new bathroom a couple of weeks
ago. no real problems and all went quite well. so, i was a bit
surprised to be woken at 1am on saturday to the sound of water running
and a hysterical girlfriend. it appears that one of the compression
joints has spontaneously exploded, allowing mains pressure water to go
everywhere. fortunately no real damage done, just a lot of mopping up
to do downstairs.

the bit i don't understand is why this joint went so suddenly. here's
the facts :

1. the pipe had just slipped straight out leaving the olive in the
service valve that the pipe had escaped from.
snip
i'd quite like to understand why this joint has failed so spectacularly
before i go trying to fix it.

Because you diddn't tighten it up enough.
The olive should form a tight metal-metal seal, with no need for PTFE.
The only case where PTFE is actually needed is if you've got damaged
pipework, or fittings, and can't really replace easily.

You should _NOT_ be able to 'pull' the pipe out as happened in this
case, without actually damaging the fitting, and exerting much, much
more force than it saw.

john2 wrote:
Redeye wrote:

5. i'd put a couple of wraps of PTFE tape over the olive as i'd been
advised that this can help stop small leaks (was this my downfall?)


IANAP
Best to remove all tape, provided the fittings are clean, unscratched
and undamaged. Tighten until the olive just grips the pipe. Add an
extra 1/6 turn to compress the olive.
No doubt proper plumbers will disagree.

john2

Th olive should be tightened enough to permanently deform the pipe. In
practice you can keep on going till you can't go no more, but somewhere
in between 'just leakproof' and 'fully home' is a happy medium.

I am not sure how I do it, but in practice when screwing up they get
tighter and tighter and then they don't get any harder to turn at
all.that mean you are now deforming the copper, not taking up the slack,
and its time to stop..or add that 1/6th turn for good luck.

The message .com
from "Redeye" contains these words:

i finished plumbing in everything in my new bathroom a couple of weeks
ago. no real problems and all went quite well. so, i was a bit
surprised to be woken at 1am on saturday to the sound of water running
and a hysterical girlfriend. it appears that one of the compression
joints has spontaneously exploded, allowing mains pressure water to go
everywhere. fortunately no real damage done, just a lot of mopping up
to do downstairs.

Comiserations. Happened to my parents in law over Christmas. They'd not
even moved into the house fully - just had new carpets and wallpaper
etc, and had never even seen most of it fitted. Pipe went while they
were away for a week - mains feed to loft tank came apart. Previous
owner was a plumber!

Just the electricity to dry the house out came to nearly a grand. Thank
heavens for insurance.

Anyway - never ever put PTFE tape on compression joints. They rely
solely on metal to metal contact. If the olive has slipped off the pipe
then it wasn't done up properly.

--
Skipweasel
Pay no attention to that man behind the curtain.

okay, thanks for the feedback.

i've come to the conclusion that i've followed bad advice which is
probably the cause of the problem. i'd also been warned not to
overtighten compression joints, but advice here seems to suggest that
isn't possible.

anyway, i think i'll replace some of my compression joints with push
fittings in the hope of avoiding a repeat disaster (although i've got a
push fit joint leaking slightly at the moment as well !!).

In an earlier contribution to this discussion,
Redeye wrote:


i'd quite like to understand why this joint has failed so
spectacularly before i go trying to fix it.

As others have said, it wasn't done up properly - and don't use PTFE tape!

If you're not sure when it's tight enough - and you get used to the 'feel'
when you've done a few - do it up and then take it apart again and check
that the olive is firmly crimped onto the pipe. If you want a belt and
braces job, smear a bit of Boss White (not PTFE tape) round the olive before
you re-assemble it - but that shouldn't be necessary on a new fitting with
new pipe.
--
Cheers,
Roger
______
Email address maintained for newsgroup use only, and not regularly
monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!

The message .com
from "Redeye" contains these words:

i've come to the conclusion that i've followed bad advice which is
probably the cause of the problem. i'd also been warned not to
overtighten compression joints, but advice here seems to suggest that
isn't possible.

Well, it is if you're a gorilla...

--
Skipweasel
Pay no attention to that man behind the curtain.

Redeye wrote:


anyway, i think i'll replace some of my compression joints with push
fittings in the hope of avoiding a repeat disaster (although i've got a
push fit joint leaking slightly at the moment as well !!).

My caution with mains pressured water extends to the belief that
properly-installed soldered fittings are the way to go unless the
consequences of a failure won't be too damaging.
Of course, this then thwarts any changes because they aren't as readily
undo-able as compression fittings.

I haven't used the new Monsoon 3 bar shower pump yet but its my first
exposure to push fittings and I must admit to being quite impressed
(with
no experience of them this isn't saying much!).
That plus the perceived speed in installation as well as easier
installation in
restricted locations makes push fittings sound interesting...

Mungo

"Redeye" wrote in
oups.com:

5. i'd put a couple of wraps of PTFE tape over the olive as i'd been
advised that this can help stop small leaks (was this my downfall?)

I think it's this that did you, making you think you had a seal when you
hadn't.

You should NEVER put jollop on a compression joint (unless, unless...) but
in case of a bodge like that - old pipe, short pipe, unremoveable olive etc
you will need to muller it well down and make damn sure it won't budge

mike

Guy King wrote:
The message .com
from "Redeye" contains these words:

i've come to the conclusion that i've followed bad advice which is
probably the cause of the problem. i'd also been warned not to
overtighten compression joints, but advice here seems to suggest that
isn't possible.

Well, it is if you're a gorilla...

Or it's 8mm pipe.
With 22mm compression fittings, you'll have a job breaking the fitting
so that it won't seal by overtightening.
It's probably possible, but you'll need a long spanner, and the pipe to
be restrained quite securely.

Redeye wrote:
after a rather more eventful weekend than i was hoping for, i'm hoping
somebody can explain this....

i finished plumbing in everything in my new bathroom a couple of weeks
ago. no real problems and all went quite well. so, i was a bit
surprised to be woken at 1am on saturday to the sound of water running
and a hysterical girlfriend. it appears that one of the compression
joints has spontaneously exploded, allowing mains pressure water to go
everywhere. fortunately no real damage done, just a lot of mopping up
to do downstairs.

the bit i don't understand is why this joint went so suddenly. here's
the facts :

1. the pipe had just slipped straight out leaving the olive in the
service valve that the pipe had escaped from.
2. the joint hasn't leaked at all in the last 2 weeks.
3. the pipe was running from a service valve horizontally about 4"
across then going to a flexi-hose which connects vertically to the
adapters which go up to the mixer tap.
4. the pipe wasn't supported by pipe clips, although it's a short run
and hardly moves at all anyway.
5. i'd put a couple of wraps of PTFE tape over the olive as i'd been
advised that this can help stop small leaks (was this my downfall?)
6. all the other compression joints i've made are absolutely fine and
have been for 2 weeks.

i'd quite like to understand why this joint has failed so spectacularly
before i go trying to fix it.

thanks
dan

I'd guess the pipe was not fully home when you tightened it.
The PTFE tape wouldn't have caused it.

The message
from Ian Stirling contains these words:

With 22mm compression fittings, you'll have a job breaking the fitting
so that it won't seal by overtightening.
It's probably possible, but you'll need a long spanner, and the pipe to
be restrained quite securely.

Doesn't everyone use two spanners? Perhaps that's where all the people
who've been having compression joint fittings are going wrong, they're
just using one spanner!

--
Skipweasel
Pay no attention to that man behind the curtain.

Guy King wrote:
The message
from Ian Stirling contains these words:

With 22mm compression fittings, you'll have a job breaking the fitting
so that it won't seal by overtightening.
It's probably possible, but you'll need a long spanner, and the pipe to
be restrained quite securely.

Doesn't everyone use two spanners? Perhaps that's where all the people
who've been having compression joint fittings are going wrong, they're
just using one spanner!

Two spanners helps - but you've still got an unbalanced torque left.

In article .com,
Redeye wrote:
i've come to the conclusion that i've followed bad advice which is
probably the cause of the problem. i'd also been warned not to
overtighten compression joints, but advice here seems to suggest that
isn't possible.

Use proper open ended spanners and tighten them till they groan. You won't
overtighten them unless using something silly like large Stilsons.

--
*There are two sides to every divorce: Yours and **** head's*

Dave Plowman London SW
To e-mail, change noise into sound.

On 8 May 2006 05:59:05 -0700, "Redeye"
wrote:

5. i'd put a couple of wraps of PTFE tape over the olive as i'd been
advised that this can help stop small leaks (was this my downfall?)

This is the reason.

Compression joints are not PTFE territory.

Guy King wrote:
[tightening compression fittings]
Doesn't everyone use two spanners? Perhaps that's where all the people
who've been having compression joint fittings are going wrong, they're
just using one spanner!

Don't you *have* to use two spanners (or a spanner and a "grip", or
two pairs of Stillsons)?

Chris Bacon wrote:
Guy King wrote:
[tightening compression fittings]
Doesn't everyone use two spanners? Perhaps that's where all the people
who've been having compression joint fittings are going wrong, they're
just using one spanner!

Don't you *have* to use two spanners (or a spanner and a "grip", or
two pairs of Stillsons)?

Depends.
If it's a valve, or something else assymetric you can hold it with one hand,
and sort-of do it up with the other.

The message
from Ian Stirling contains these words:

Doesn't everyone use two spanners? Perhaps that's where all the people
who've been having compression joint fittings are going wrong, they're
just using one spanner!

Two spanners helps - but you've still got an unbalanced torque left.

Mitigated with offset spanners. Anyway, it was the self limiting by the
user of the applied torque to do up the fitting I was wondering about.
With only one spanner even quite inept people will limit the tightness
because the other half of the fitting is starting to turn.

--
Skipweasel
Pay no attention to that man behind the curtain.

The message
from Chris Bacon contains these words:

[tightening compression fittings]
Doesn't everyone use two spanners? Perhaps that's where all the people
who've been having compression joint fittings are going wrong, they're
just using one spanner!

Don't you *have* to use two spanners (or a spanner and a "grip", or
two pairs of Stillsons)?

I'd have trouble doing otherwise, but I was wondering whether failing to
do so might be the root of the trouble people are having with
compression fittings.

--
Skipweasel
Pay no attention to that man behind the curtain.

The Natural Philosopher wrote:
john2 wrote:
Redeye wrote:

5. i'd put a couple of wraps of PTFE tape over the olive as i'd been
advised that this can help stop small leaks (was this my downfall?)


IANAP
Best to remove all tape, provided the fittings are clean, unscratched
and undamaged. Tighten until the olive just grips the pipe. Add an
extra 1/6 turn to compress the olive.
No doubt proper plumbers will disagree.

john2

Th olive should be tightened enough to permanently deform the pipe.

eh ?

Redeye wrote:
okay, thanks for the feedback.

i've come to the conclusion that i've followed bad advice which is
probably the cause of the problem. i'd also been warned not to
overtighten compression joints, but advice here seems to suggest that
isn't possible.

it is.

Ian Stirling wrote:
Guy King wrote:
The message
from Ian Stirling contains these words:

With 22mm compression fittings, you'll have a job breaking the
fitting so that it won't seal by overtightening.
It's probably possible, but you'll need a long spanner, and the
pipe to be restrained quite securely.

Doesn't everyone use two spanners? Perhaps that's where all the
people who've been having compression joint fittings are going
wrong, they're just using one spanner!

Two spanners helps - but you've still got an unbalanced torque left.

IMEE it's 2 pairs of grips. no spanners.

mike wrote:
"Redeye" wrote in
oups.com:

5. i'd put a couple of wraps of PTFE tape over the olive as i'd been
advised that this can help stop small leaks (was this my downfall?)

I think it's this that did you, making you think you had a seal when
you hadn't.

You should NEVER put jollop on a compression joint (unless,
unless...)

oh, really :-)

The message
from "." contains these words:

Th olive should be tightened enough to permanently deform the pipe.

eh ?

Seems clear enough to me. The clamping by the nut should tighten the
olive onto the pipe sufficiently to indent the pipe all the way round -
that's how they work.

--
Skipweasel
Pay no attention to that man behind the curtain.

Redeye wrote:
okay, thanks for the feedback.

i've come to the conclusion that i've followed bad advice which is
probably the cause of the problem. i'd also been warned not to
overtighten compression joints, but advice here seems to suggest that
isn't possible.

I think it is. If you tighten it up as far as it will go, if you need to
take the joint apart at any future date you'll have a hard time getting it
watertight again as there's nothing left to compress.

Tim

Guy King wrote:
The message
from "." contains these words:

Th olive should be tightened enough to permanently deform the pipe.

eh ?

Seems clear enough to me. The clamping by the nut should tighten the
olive onto the pipe sufficiently to indent the pipe all the way round
- that's how they work.

/deform/ the pipe (sic) ?

overtightening the joint deforms the /tube/, that's what causes leaks.

a /light/ touch of jollop, good control on the static part of the joint and
knowing when the joint is nipped up all takes experience and it's for
that reason that them who are not dealing with compression joints
day in, day out should take the time to learn how to solder a joint.

YMMWV, of course.

.. wrote:
Guy King wrote:
The message from "." contains these words:
Th olive should be tightened enough to permanently deform the pipe.
eh ?

Seems clear enough to me. The clamping by the nut should tighten the
olive onto the pipe sufficiently to indent the pipe all the way round
- that's how they work.


/deform/ the pipe (sic) ?

overtightening the joint deforms the /tube/, that's what causes leaks.

a /light/ touch of jollop, good control on the static part of the joint and
knowing when the joint is nipped up all takes experience and it's for
that reason that them who are not dealing with compression joints
day in, day out should take the time to learn how to solder a joint.

YMMWV, of course.

If the olive does not indent, how has the joint any mechanical
strength at all? ISTR that a compression joint in 15mm is safe
to 45 bar, but ICBW. They shouldn't be over-tightened, else
wrinkles are a problem, that's why they leak AFAIK.

On Mon, 08 May 2006 05:59:05 -0700, Redeye wrote:

after a rather more eventful weekend than i was hoping for, i'm hoping
somebody can explain this....

i finished plumbing in everything in my new bathroom a couple of weeks
ago. no real problems and all went quite well. so, i was a bit
surprised to be woken at 1am on saturday to the sound of water running
and a hysterical girlfriend. it appears that one of the compression
joints has spontaneously exploded, allowing mains pressure water to go
everywhere. fortunately no real damage done, just a lot of mopping up
to do downstairs.

the bit i don't understand is why this joint went so suddenly. here's
the facts :

1. the pipe had just slipped straight out leaving the olive in the
service valve that the pipe had escaped from.
2. the joint hasn't leaked at all in the last 2 weeks.
3. the pipe was running from a service valve horizontally about 4"
across then going to a flexi-hose which connects vertically to the
adapters which go up to the mixer tap.
4. the pipe wasn't supported by pipe clips, although it's a short run
and hardly moves at all anyway.
5. i'd put a couple of wraps of PTFE tape over the olive as i'd been
advised that this can help stop small leaks (was this my downfall?)
6. all the other compression joints i've made are absolutely fine and
have been for 2 weeks.

i'd quite like to understand why this joint has failed so spectacularly
before i go trying to fix it.


Either the pipe was not inserted past the olive (it may have been but then
pulled out before tightening), in this case the tightening tends to roll
the olive over the end of the pipe and tends to expel the pipe.

The fitting was in noway adequately tightened.
If the pipe/fitting are in good alignment and everything is clean then the
back nut will "finger spin" up to the "bite point". After that I would say
you are looking at adding 2-4 'flats' (1/3 to 2/3 of a turn to tighten
most fittings).

HTH


--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html

Redeye wrote:
okay, thanks for the feedback.

i've come to the conclusion that i've followed bad advice which is
probably the cause of the problem.

Probably. You came to the right place for conflicting advice ;-)

i'd also been warned not to overtighten compression joints, but advice here seems to
suggest that isn't possible.

Definitely possible. You can overtighten it enough to damage the pipe
(and hence the joint) if you go at it like some gorilla. There's a
distinct difference between loose, tight (watertight) and overtight.

I think experience has shown you what 'loose' feels like.

anyway, i think i'll replace some of my compression joints with push
fittings in the hope of avoiding a repeat disaster (although i've got a
push fit joint leaking slightly at the moment as well !!).

I wouldn't choose pushfit over compression, especially in hot water
situations, no matter what 25 year guarantee the pushfit manufacturers
give .....

All plumbing with whatever fitting of choice takes practice. It's easy
to undertighten a compression if you've not had much experience of
them, as much as it's easy to make a bad solder joint.

Practice. Then take it apart (compression) or heat up a practice solder
joint and separate to check how well the joint has 'wetted'. Then
you'll know how much solder is enough ..

Cheers

Paul.

wrote:
Redeye wrote:
okay, thanks for the feedback.

i've come to the conclusion that i've followed bad advice which is
probably the cause of the problem.

Probably. You came to the right place for conflicting advice ;-)

i'd also been warned not to overtighten compression joints, but
advice here seems to suggest that isn't possible.

Definitely possible. You can overtighten it enough to damage the pipe
(and hence the joint) if you go at it like some gorilla. There's a
distinct difference between loose, tight (watertight) and overtight.

I think experience has shown you what 'loose' feels like.

anyway, i think i'll replace some of my compression joints with push
fittings in the hope of avoiding a repeat disaster (although i've
got a
push fit joint leaking slightly at the moment as well !!).

I wouldn't choose pushfit over compression, especially in hot water
situations, no matter what 25 year guarantee the pushfit manufacturers
give .....

I would if I couldn't trust my comression skills :-)

In article .uk,
Ed Sirett writes
i'd quite like to understand why this joint has failed so spectacularly
before i go trying to fix it.


Either the pipe was not inserted past the olive (it may have been but then
pulled out before tightening), in this case the tightening tends to roll
the olive over the end of the pipe and tends to expel the pipe.

The fitting was in noway adequately tightened.
If the pipe/fitting are in good alignment and everything is clean then the
back nut will "finger spin" up to the "bite point". After that I would say
you are looking at adding 2-4 'flats' (1/3 to 2/3 of a turn to tighten
most fittings).

The voice of reason from one who does this for a living, respect.
--
fred
Plusnet - I hope you like vanilla

The message
from "." contains these words:

Seems clear enough to me. The clamping by the nut should tighten the
olive onto the pipe sufficiently to indent the pipe all the way round
- that's how they work.

/deform/ the pipe (sic) ?

That's right - deform the pipe. The olive will be pressed into the pipe,
deforming it in a ring all the way round.

What's wrong with that?

--
Skipweasel
Pay no attention to that man behind the curtain.

Guy King wrote:
The message
from "." contains these words:

Seems clear enough to me. The clamping by the nut should tighten the
olive onto the pipe sufficiently to indent the pipe all the way
round - that's how they work.

/deform/ the pipe (sic) ?

That's right - deform the pipe. The olive will be pressed into the
pipe, deforming it in a ring all the way round.

What's wrong with that?

1/ it's copper /tube/

2/ if the olive deforms the tube the joint is over tightened and will weep

In article ,
EricP wrote:
5. i'd put a couple of wraps of PTFE tape over the olive as i'd been
advised that this can help stop small leaks (was this my downfall?)

This is the reason.

No it's not.

Compression joints are not PTFE territory.

I'm one of those who does use PTFE round the olive. And non of mine leak -
and certainly don't pull apart. The only way a compression fitting can
pull apart is when it's not properly tightened.

--
*Depression is merely anger without enthusiasm *

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
Tim Downie wrote:
I think it is. If you tighten it up as far as it will go, if you need
to take the joint apart at any future date you'll have a hard time
getting it watertight again as there's nothing left to compress.

Not so - once the olive is compressed on the pipe it remains compressed.
The tapers on the olive and body are then the seal - and if in good
condition will seal again ok even if moved round. However, an old fitting
may well have some corrosion on the seats due to electrolytic action and
if so will be difficult to seal.

--
*Constipated People Don't Give A Crap*

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
. wrote:
/deform/ the pipe (sic) ?

overtightening the joint deforms the /tube/, that's what causes leaks.

If it doesn't 'deform' the pipe slightly it isn't correctly made. It's
impossible to pull off an olive from a properly made joint, and this
wouldn't be so if it was merely friction.

--
*(over a sketch of the titanic) "The boat sank - get over it

Dave Plowman London SW
To e-mail, change noise into sound.

Dave Plowman (News) wrote:
In article ,
Tim Downie wrote:
I think it is. If you tighten it up as far as it will go, if you need
to take the joint apart at any future date you'll have a hard time
getting it watertight again as there's nothing left to compress.

Not so - once the olive is compressed on the pipe it remains compressed.
The tapers on the olive and body are then the seal - and if in good
condition will seal again ok even if moved round. However, an old fitting
may well have some corrosion on the seats due to electrolytic action and
if so will be difficult to seal.


.... and that's the one time I put some PTFE tape on the olive. To form
a new seat.

R.

Dan,

Temp change, pressure change??? one of those things.

Why are you using PTFE tape, Ive never found a need to use it, i allways
use new pipes and fittings, there cheap enough esp if you go to a plumbers
merchant.

Kev




"Redeye" wrote in message
oups.com...
after a rather more eventful weekend than i was hoping for, i'm hoping
somebody can explain this....

i finished plumbing in everything in my new bathroom a couple of weeks
ago. no real problems and all went quite well. so, i was a bit
surprised to be woken at 1am on saturday to the sound of water running
and a hysterical girlfriend. it appears that one of the compression
joints has spontaneously exploded, allowing mains pressure water to go
everywhere. fortunately no real damage done, just a lot of mopping up
to do downstairs.

the bit i don't understand is why this joint went so suddenly. here's
the facts :

1. the pipe had just slipped straight out leaving the olive in the
service valve that the pipe had escaped from.
2. the joint hasn't leaked at all in the last 2 weeks.
3. the pipe was running from a service valve horizontally about 4"
across then going to a flexi-hose which connects vertically to the
adapters which go up to the mixer tap.
4. the pipe wasn't supported by pipe clips, although it's a short run
and hardly moves at all anyway.
5. i'd put a couple of wraps of PTFE tape over the olive as i'd been
advised that this can help stop small leaks (was this my downfall?)
6. all the other compression joints i've made are absolutely fine and
have been for 2 weeks.

i'd quite like to understand why this joint has failed so spectacularly
before i go trying to fix it.

thanks
dan

In article ,
Dave Plowman (News) wrote:
In article .com,
Redeye wrote:
i've come to the conclusion that i've followed bad advice which is
probably the cause of the problem. i'd also been warned not to
overtighten compression joints, but advice here seems to suggest that
isn't possible.

Use proper open ended spanners and tighten them till they groan. You won't
overtighten them unless using something silly like large Stilsons.

Yup, all the joints that I'd convinced myself were leaking
cos I'd over-tightened them turned out to be not tight
enough. Just an extra 1/8 turn was all that was needed for
most of them.

G.