What the... ? Corroding copper pipes - pinholes.

[jlacd]

While dealing with this mess...

//www.diynot.com/forums/viewtopic.php?t=155736

... I have found copper pipes with pinhole leaks. About 4m of 28mm piping (probably late 1960's) with several drips. This is cold feed to upstairs, and only on horizontal run between ceiling and floorboards. No abrasion - these occur in "free" running sections of the pipe. Only on cold side, and all appear to be on lower half of the pipe section.

Some of them are very slow weeps from apparently uncorroded sections of pipe, like this:

pipe1

• jlacd
• 18 Nov 2008
• 1

Others are not dripping, but have corrosion around them, like this:

pipe2

• jlacd
• 18 Nov 2008
• 1

And the union on these runs look pretty scabby to me:

pipe3

• jlacd
• 18 Nov 2008
• 1

What I'd like to know is....

1> Why has this happened?
2> What can I do? Can I realistically repair? I thought I could do this:
> turn off water to relieve pressure, and drain down
> *GENTLY* wire-wool affected spots, and clean with meths
> using rubber-solution glue, glue a bandage of bicycle inner-tube round affected area
> apply a jubliee-clip over the rubber, ensuring it does not cut into rubber, nor touch copper pipe (so no electrolysis set up)

Would this work? Any other solutions... I'd *REALLY* rather not get into replacing it. If I don't - what's the long-term prognosis - is it just going to get worse and worse, so I end up with a soggy ceiling again!?!?

I am SOOOOO sick of this place - everything I look at turns out to be a botched job or just plain sh!t.

Cheer me up, someone!

 

[seco services]

looks more like the pipes been damaged than anything.

 

[Rico99]

Hi there,

Not much option IMHO

these

or

these

With a new section of pipe in between. Rico

 

[jlacd]

looks more like the pipes been damaged than anything.

Hmmm ... pipes really look fine - no dings or creases. Could spots of solder or flux internally be causing corrosion from the inside?

Hi there,

Not much option IMHO

these

or

these

With a new section of pipe in between. Rico

Erk..... with 10 or more in a 4m run, there'd be more join than pipe... would be better off just getting the run redone.

Cheers guys.

 

[seco services]

looking at the pics they look like indents maybe the light.

 

[WDIK]

would your header tank be zinc coated by any chance?

 

[jlacd]

looking at the pics they look like indents maybe the light.

Just the light... pipe is round.

would your header tank be zinc coated by any chance?

No header tank - it's a cold-water feed to upstairs bathroom. There *may* have been a header tank years ago (there's a dead one in the loft), but I didn't think you got them on cold-water side (I wouldn't like to be drinking out of an uncovered header-tank located in a loft full of wasps, slaters and cobwebs!)

 

[namsag]

Pin holes are more than likely caused by the old style of self cleaning flux that used to be about years ago it stays active and eventually rots through the pipe if it was not wiped off properly

 

[WDIK]

it looks like electrolytic corosion to me

 

[jlacd]

Ok cool.... now what about my repair idea?

 

[Mushybees]

The first photo looks like one of those rubbish, self tapping fittings have been used on it

 

[jlacd]

The first photo looks like one of those rubbish, self tapping fittings have been used on it

Not sure what you mean. It's just a picture of a tiny drip coming from a 28mm pipe. No self-tapping fittings anywhere on it's length. The light's kind of funny - when my camera gets that close in Macro mode, part of the image dosen't get as much flash light. Is that what you mean? I can assure you it's just an ordinary length of pipe - no fittings or oddities.

 

[JPC]

cant you just replace the pipe with plastic...easy job and relatively cheap

 

[ddraig]

As has been mentioned, its either electrolytic corrosion, or residue of flux, is the pipe a cold main??? are there one or two pipes side by side??? or does there seem to be any indication that another pipe was running along side??

 

[John506]

> using rubber-solution glue, glue a bandage of bicycle inner-tube round affected area
> apply a jubliee-clip over the rubber, ensuring it does not cut into rubber, nor touch copper pipe (so no electrolysis set up)

Well that's one way of DIYing it... or you could just replace the small section of pipe, with peace of mind it won't leak (if done correctly).