Have had a pinhole leak this year, and also a few years back, so started
looking at my Copper house water plumbing a bit.
Noticed several areas with that bluish-green coating on it.
a. Is this indicative of a pinhole leak developing ?
b. what actually is this bluish-green "stuff" ?
c. Is it a reaction of the Copper with the outside air, and thus
developing on the pipe's outside, or it coming from the inside ?
d. Interesting in that I see it in the middle of a run, here and there,
so it's unlikely that it is caused by any soldering flux residual.
I do also see it at joints, and am wondering if it is caused, here, by a
soldering flux residual ?
Any thoughts on the bluish-green stuff, and pinhole leaks would be most
appreciated.
BTW: how common are pinhole leaks in older (around 35 yr old) homes ?
Thanks,
Bob
Copper pinholes show up most commonly in houses with well water,
sometime exacerbated by electrolysis from copper-iron junctions. In
worst cases it is like a cancer and just continues for years until
failures are intolerable. Assess your situation with this in mind. If
you want to eliminate the problem, eliminate the copper. CPVC, and PEX
are well regarded replacements, code approved nearly everywhere, and
have many advantages with the exception of electrical grounding. A
competent journeyman plumber with knowledge of isolation of
electrolytic sources might be able to correct such problems and save
replacing the major parts of your system.
Joe
The "stuff" is generally a product of corrosion of the copper from
condensation on the pipe. If you have pinhole leaks developing, plan to
replace all of the plumbing soon. I had a house with rather hard well
water which after 40 or 50 years developed pinhole leaks since it was
corroded from the inside out. After a few leak repairs I just picked up
the necessary supplies and on one weekend ripped out all the old
plumbing and replumbed. That was about 20 years ago and it's had no
further issues.
There are three different standards of copper pipe classified by the
thickness of the copper. Type M is the thinnest with type L thicker
and type K the thickest. The type of the pipe is printed on the pipe.
You may still be able to read what type it is if you look closely.
Please try to read what type your pipes are and let us know and when
you replace your pipes make sure that it is type K this time. In some
cities type K is mandatory.
If you have had one pinhole leak recently you are probably destined to
have several more soon...
Can you describe where the pinhole leak occurred? Was it near a
fitting which turned a corner, that sort of leak often occurs because
of the velocity of the water at the corner eating away at the pipe
which is helped by very bad water chemistry or a plumber who used
way too much flux when installing the pipes...
a. It can be, or it can be indicative of a lot of humidity in the
area
where the exposed pipes live...
b. It depends on the chemistry involved, it could be patina, which
naturally occurs on un-coated copper like roofs and gutters, etc...
Or it could be specific chemicals namely: Copper(II) Chloride or
Copper(II) Carbonate depending on your local water chemistry...
c. It could be either or, if your pipes are leaking the process of
corrosion is a mechanical and chemical breakdown and that can
spread out on the exterior surface of the pipe after a pinhole
leak breaks through... Your pipes could have also formed this
color on the outside of them from sweating and having the water
condensation which formed on them chemically react with the
exposed copper...
d. Define "middle of the run" are you saying that it is nowhere
near a soldered fitting or joint? Remember the pipes are empty
when originally soldered, excessive amounts of flux would be
washed away and settle elsewhere in the piping upon filling the
system with water...
Sounds like your water chemistry needs to be analyized...
Not knowing whether you are on city provided water or a well
makes a difference... More chloride chemical compounds in
city water usually, more hard carbonate type compounds in
well water... You could also have an issue with sulfides/sulfates
which are reacting with your pipes...
Without knowing what thickness of copper pipe your house has
or your local water chemistry and the volume of water you are
using its not easy to nail down whether 35 years of use is good
or bad performance...
~~ Evan
The bluish green stuff is predominately copper carbonate and copper
hydroxide. Formed when oxygen , carbon dioxide and copper react.
http://en.wikipedia.org/wiki/Copper_carbonate
http://en.wikipedia.org/wiki/Copper(II)_hydroxide
A lot of the problems arise with copper pipe due to bad manufacturing
techniques. Traces of die metals and lubricants initiate the
corrosion process which is then self sustaining. Also if there is
galvanised iron elsewhere in your system (zinc) you get electrolytic
effects going on.
If the pipe is very thin, holes soon appear.
Some fluxes used in the soldering process have a similar effect.
Thanks for such good info.; really appreciate it.
Some clarifications that were requested:
Yes, it is Type M, apparently. The thin stuff.
Both pinholes developed in a horiz run, nowhere near a joint or elbow.
Thanks again,
Bob
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The house I replumbed developed it's pinhole leaks mid run. When I
replumbed I used only type L.