Just a quick(!) question, why would a weeping soldered fitting continue
to weep at the same rate when the supply is turned off and the pressure
removed (by opening a tap) ?

Is this just a "They all do that" thing?


....

Background if interested, this is a soldered "T" in an inaccessible
place (aren't they always?) and it's currently weeping at about 1 drop
an hour. I'm worried that could worsen, possibly without further warning.

The weep is coming from a "carbuncle" on the fitting itself, I'm
guessing it's a flux residue problem.

Getting to it is not going to be easy, barely got enough access to see
it, the current preferred plan is to just run another pipe and nix the
bath tap that the other end of this one is connected to. Never use that
tap anyway (because shower) and there is a refit in the budget at some
point

In article ,
Lee wrote:
Just a quick(!) question, why would a weeping soldered fitting continue
to weep at the same rate when the supply is turned off and the pressure
removed (by opening a tap) ?

Is this just a "They all do that" thing?

It can't leak water if there's none in the pipes. ;-)

But running a tap isn't guaranteed to empty the pipes completely. As
you'll find if attempting to solder ones which have been in use.

I tend to blow them through with a compressed air supply before attempting
a repair.

...

Background if interested, this is a soldered "T" in an inaccessible
place (aren't they always?) and it's currently weeping at about 1 drop
an hour. I'm worried that could worsen, possibly without further warning.

You need quite a bit of space to dismantle a soldered joint and re-make
properly. But then you do with a compression fitting too.

The weep is coming from a "carbuncle" on the fitting itself, I'm
guessing it's a flux residue problem.

I've seen brand new fittings with a pin hole in them. Before just how well
soldered it was comes into it.

Getting to it is not going to be easy, barely got enough access to see
it, the current preferred plan is to just run another pipe and nix the
bath tap that the other end of this one is connected to. Never use that
tap anyway (because shower) and there is a refit in the budget at some
point

Could you cut the pipes in a more accessible place and perhaps
pre-fabricate the T including pipe ends? Then used end feed couplers?

--
*Everyone has a photographic memory. Some just don't have film*

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

On 01/03/2018 13:32, Dave Plowman (News) wrote:
In article ,
Lee wrote:
Just a quick(!) question, why would a weeping soldered fitting continue
to weep at the same rate when the supply is turned off and the pressure
removed (by opening a tap) ?

Is this just a "They all do that" thing?

You said it was dripping at 1 drop per hour. So capillary action is
possibly more important than pressure.




It can't leak water if there's none in the pipes. ;-)

But running a tap isn't guaranteed to empty the pipes completely. As
you'll find if attempting to solder ones which have been in use.

I tend to blow them through with a compressed air supply before attempting
a repair.


I used a wet and dry vacuum cleaner recently. It worked a treat.



Could you cut the pipes in a more accessible place and perhaps
pre-fabricate the T including pipe ends? Then used end feed couplers?


Push fit might be a lot easier in a confined space.

On Thu, 1 Mar 2018 12:33:01 +0000, Lee wrote:

Just a quick(!) question, why would a weeping soldered fitting continue
to weep at the same rate when the supply is turned off and the pressure
removed (by opening a tap) ?

If there is any water left above the weep the weep is still under
presure from the weight of that water.

The weep is coming from a "carbuncle" on the fitting itself, I'm
guessing it's a flux residue problem.

Or faulty fitting? A "temporary" fix for something that slow would
be to bind it with self amalgamting tape.

--
Cheers
Dave.

On 01/03/2018 13:49, Dave Liquorice wrote:
On Thu, 1 Mar 2018 12:33:01 +0000, Lee wrote:

Just a quick(!) question, why would a weeping soldered fitting continue
to weep at the same rate when the supply is turned off and the pressure
removed (by opening a tap) ?

If there is any water left above the weep the weep is still under
presure from the weight of that water.

The weep is coming from a "carbuncle" on the fitting itself, I'm
guessing it's a flux residue problem.

Or faulty fitting? A "temporary" fix for something that slow would
be to bind it with self amalgamting tape.


I have some of that, but to be fair if I had the access to do that it
wouldn't be too much harder to remake the fitting

On 01/03/2018 13:32, Dave Plowman (News) wrote:
In article ,
Lee wrote:
Just a quick(!) question, why would a weeping soldered fitting continue

Snip

It can't leak water if there's none in the pipes. ;-)

Indeed I was just surprised a change of pressure didn't change the
amount. But probably it is capillary action then, as GB notes.

Snip

Could you cut the pipes in a more accessible place and perhaps
pre-fabricate the T including pipe ends? Then used end feed couplers?


Not unless I either change size considerably or pull the bath out, which
would necessitate a fair degree of destruction due to the way it's been
installed. Fortunately access to the shower pipes is a little more
straightforward so an alternate pipe route looks favourable.

On 01/03/2018 13:48, GB wrote:

Big Snip


Push fit might be a lot easier in a confined space.


That's the current plan...

On Thursday, March 1, 2018 at 1:49:37 PM UTC, Dave Liquorice wrote:
On Thu, 1 Mar 2018 12:33:01 +0000, Lee wrote:

Just a quick(!) question, why would a weeping soldered fitting continue
to weep at the same rate when the supply is turned off and the pressure
removed (by opening a tap) ?

If there is any water left above the weep the weep is still under
presure from the weight of that water.



.... and so turning off the tap might actually result in the leak stopping.

Robert

On Thursday, 1 March 2018 14:21:36 UTC, wrote:
On Thursday, March 1, 2018 at 1:49:37 PM UTC, Dave Liquorice wrote:
On Thu, 1 Mar 2018 12:33:01 +0000, Lee wrote:

Just a quick(!) question, why would a weeping soldered fitting continue
to weep at the same rate when the supply is turned off and the pressure
removed (by opening a tap) ?

If there is any water left above the weep the weep is still under
presure from the weight of that water.



... and so turning off the tap might actually result in the leak stopping..

Robert

How easy is it to get a blow torch to it? During some building work I was having done, the builder knocked a pipe which was below any drain off possibilities. A soldered joint started leaking so I ended up getting 2 blow torches to it and eventually was able to get it hot enough to melt the solder (having added flux first) and fix the joint. From memory (it was a good few years ago!) I *think* I ended up draining what I could first so assume the blow torches effectively evaporated the water enough to get hot enough for the solder to flow in.

On 01/03/18 15:54, wrote:
On Thursday, 1 March 2018 14:21:36 UTC, wrote:
On Thursday, March 1, 2018 at 1:49:37 PM UTC, Dave Liquorice wrote:
On Thu, 1 Mar 2018 12:33:01 +0000, Lee wrote:

Just a quick(!) question, why would a weeping soldered fitting continue
to weep at the same rate when the supply is turned off and the pressure
removed (by opening a tap) ?

If there is any water left above the weep the weep is still under
presure from the weight of that water.



... and so turning off the tap might actually result in the leak stopping.

Robert

How easy is it to get a blow torch to it? During some building work I was having done, the builder knocked a pipe which was below any drain off possibilities. A soldered joint started leaking so I ended up getting 2 blow torches to it and eventually was able to get it hot enough to melt the solder (having added flux first) and fix the joint. From memory (it was a good few years ago!) I *think* I ended up draining what I could first so assume the blow torches effectively evaporated the water enough to get hot enough for the solder to flow in.

BTDTGTTS but it can take an awful lot of propane


--
Microsoft : the best reason to go to Linux that ever existed.

On 01/03/2018 15:58, The Natural Philosopher wrote:
On 01/03/18 15:54, wrote:
On Thursday, 1 March 2018 14:21:36 UTC, Â* wrote:
On Thursday, March 1, 2018 at 1:49:37 PM UTC, Dave Liquorice wrote:
On Thu, 1 Mar 2018 12:33:01 +0000, Lee wrote:

Just a quick(!) question, why would a weeping soldered fitting
continue
to weep at the same rate when the supply is turned off and the
pressure
removed (by opening a tap) ?

If there is any water left above the weep the weep is still under
presure from the weight of that water.



... and so turning off the tap might actually result in the leak
stopping.

Robert

How easy is it to get a blow torch to it? During some building work I
was having done, the builder knocked a pipe which was below any drain
off possibilities.Â* A soldered joint started leaking so I ended up
getting 2 blow torches to it and eventually was able to get it hot
enough to melt the solder (having added flux first) and fix the
joint.Â* From memory (it was a good few years ago!) I *think* I ended
up draining what I could first so assume the blow torches effectively
evaporated the water enough to get hot enough for the solder to flow in.

BTDTGTTS but it can take an awful lot of propane


A better option than this or tape would be the special epoxy putty made
for plumbers. I had a somewhat larger drip from a hot water cylinder
once and used this for a "temporary" repair which in fact lasted years
before I changed the cylinder for other reasons. You can apply this on
to wet surfaces. I didn't even drain the cylinder, so it had a pressure
of about 6 foot head (i.e. 0.2 bar or 3 psi, much less than mains water
pressure, but if you have the mains off and the tap open for the hour or
so it takes to set, you should be OK.

In article ,
wrote:
How easy is it to get a blow torch to it? During some building work I
was having done, the builder knocked a pipe which was below any drain
off possibilities. A soldered joint started leaking so I ended up
getting 2 blow torches to it and eventually was able to get it hot
enough to melt the solder (having added flux first) and fix the joint.
From memory (it was a good few years ago!) I *think* I ended up draining
what I could first so assume the blow torches effectively evaporated the
water enough to get hot enough for the solder to flow in.

Thing with soldering a pipe which has water in it is even if you do get it
hot enough, there's a chance the steam generated will stop the solder
joint being made properly.

--
*You're never too old to learn something stupid.

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

On Thu, 1 Mar 2018 12:33:01 +0000
Lee wrote:

Just a quick(!) question, why would a weeping soldered fitting
continue to weep at the same rate when the supply is turned off and
the pressure removed (by opening a tap) ?

Are you sure it's a leak and not condensation?