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jig

join:2001-01-05
Hacienda Heights, CA

copper pipe, green spots

we've ripped off the ceiling to repair after we found a pin hole leak in a joint of a copper water pipe - the hot water line. nearby is the cold water line.

the hot water line has a bunch of green spots on it, and the cold water line does not. it appears that both are class M 1/2" copper (feels light).

now, i think the green spots are something that's melted to the pipe. there was some batting insulation all over the pipe in that area.... but i don't think fiberglass would melt. of course, i'm not sure it was fiberglass, and there are some fibers that have stuck to the green spots.

a contractor has guessed that the spots are the beginnings of pin leaks. i don't think that makes sense, especially since the leak we just fixed was at a crappily done triple elbow and T joint. (boo)

anyway, i'm just wondering if anyone else has seen something like that, and whether they do indicate failing pipe. aside from the heat, our whole system has, in the past, been at very high pressures - like 100-110 psi (regulator was broken). as mentioned above, however, the cold pipe doesn't have any green spots.

thanks for any help,

-jig
--
Catapultam habeo. Nisi pecuniam omnem mihi dabis, ad caput tuum saxum immane mittam.



aurgathor

join:2002-12-01
Lynnwood, WA
kudos:1

Many salts of the copper are green, so those green spots are most likely some copper compounds.

In general, higher temperature speeds up chemical reactions, and that may explain why only the hot line has the green spots. Copper is reasonably inert at room temperature, but it will still react with certain naturally occurring compounds, most notably hydrogen-sulfide.
--
Bachmann 2012!



norton

join:2005-08-03
Howard City, MI
reply to jig

i have an older home and have every type of pipe in here that you can imagine. if you have it open why not run pex tubing and replace it all. if you have 1 problem joint you might have several.



owlyn
Premium,MVM
join:2004-06-05
Newtown, PA
Reviews:
·Comcast
reply to jig

Pin hole leaks are like roaches. You don't have just one. After my 3rd leak, I replaced everything with Pex, except for one bathroom that was going to be remodeled later and was too messy to do at the time. You guessed it- got a leak. Bathroom just got finished being remodeled, and we are now 100% Pex.



Nonamenoage

@verizon.net
reply to jig

If they are green around fittings it could be from the flux when they soldered. If they don't wipe fittings down really good after soldering then over time it will turn green cause a reaction and start to eat through Cooper. Depending how long it's been like that, you best bet would be to replace.



jig

join:2001-01-05
Hacienda Heights, CA

the green spots are along the length of the pipe, and are large - maybe the size of two fingers pressed onto the pipe. they don't seem to be particularly prevalent at joints.

looking at pex, i can see the benefit to using it as a replacement, but i'll probably still replace with copper, if i do replace. i'm a bit of a scaredycat when it comes to plastic piping. i think most water filter systems use pex for their tubing, correct?

because of the repair, we have access to all the water piping in the house except for a single dedicated run to the master shower. we're currently thinking that we'll keep the ceiling off for a while while we contemplate plumbing changes and relocating the gas-powered water heater and the HVAC system.

both the water heater and the HVAC are on the upper level (main living level), situated in an enclosed staircase between the lower level and the upper. the water heater seems to cause a lot of environmental heating in the enclosed staircase (poor insulation?), so there's a question whether it makes sense to put it in the lowest part of the house where it could heat everything, rather than just the stairway (especially if we install a circulation loop for the hot water side - timed for morning only). at the same time, relocating it would cut out a lot of unnecessary piping that loops the water heater into the piping under the floor of the upper. we'll be more likely to replace the piping if we relocate the water heater, as we'd be adding insulation to the pipe and such. of course, if another leak shows up, that's also an incentive to replace.

anyway, that's why we want to figure out if the spots are indicative of weak pipes. if we're going to replace the pipes anyway, perhaps soon, we'll probably tie in a lot of other work that could be done - i want to build in a new manifold for a whole house filter and perhaps a water softener, and may want to reroute the water main, especially if it looks like they used the same type M copper pipe to run that main to the house (M seems pretty thin).
--
Catapultam habeo. Nisi pecuniam omnem mihi dabis, ad caput tuum saxum immane mittam.



SandShark
Long may you run
Premium,MVM
join:2000-05-23
Santa Fe, TX
kudos:3

It has been my experience that copper turns green with age as it is exposed to the atmosphere. It's called a patina or verdigris. That's why the Statue of Liberty looks the way it does.



mackey
Premium
join:2007-08-20
kudos:10
reply to jig

Where was the pinhole leak? If it was in the solid body of the fitting then you're going to have problems elsewhere. If it was just in the solder then it was probably just a bad joint and you should be fine.

The green is the copper corroding. It could be that the leak was leaking for a while and the insulation held the water to pipe, in which case it's probably fine. You can try lightly scraping the pipe to see if it's just on the surface - if it is then you're probably fine. If it's actually in the pipe, or if the scraping creates another leak, then you're going to have problems...

Where I used to live a lot of people had wells, and the water in the area was notorious for eating through copper. Pretty much everyone had to replace it with CPVC. The people on city water didn't seem to have this issue though.

/M



jig

join:2001-01-05
Hacienda Heights, CA

that's interesting to know... we have fairly hard water in general, but it's city water. i'll do the scrape test and post some pictures.

also - i know about the general patina of Cu, but these are spots, not something that's over all the exposed surface. but, you bring up a good point, which is that Cu turns green when it's subjected to water (i think). that means that there's water at each spot. so, either there's a teeny tiny leak at each spot, OR it means that water is condensing on the hot water pipes for some reason, and in spots. huh. i suppose that it could also be water dripping onto it from above, and the heat has just accelerated the tarnish on the hot water pipes...

the scrape test will at least rule out the teeny tiny leak hypothesis.
--
Catapultam habeo. Nisi pecuniam omnem mihi dabis, ad caput tuum saxum immane mittam.


shezams
My Other Car Is A Zamboni
Premium
join:2001-08-14
Hyattsville, MD

If you have a pinhole issue it is corrosion from the inside out - and sometimes they will seal themselves - but not forever. Generally you would not expect condensation on a Hot water pipe, since it is hotter than ambient. Consider replacing your piping if it is exposed. Pinholes do seem to come in groups.
--
Simple rules - no offsides, no intent to maim, everything else is all good!



owlyn
Premium,MVM
join:2004-06-05
Newtown, PA
Reviews:
·Comcast
reply to jig

My problem was also due to the use of M copper. You should absolutely replace everything. The problem will get worse. Don't be scared of Pex- it is great stuff. The plumbers and other contractors I've worked with all love it. I didn't do a manifold, as it would have been too costly and wasn't really needed in my case. Instead, we used 1/2" Pex as a main feed, and then split off 1/4" Pex to all the fixtures. We have far more water flow then we ever had before. Not all of that was due to the 1/2" main. Pex itself produces less friction with the water than copper, and there are also fewer 90 degree angles. Another advantage is that it won't break if you lose heat in the wintertime- it expands, and then reduces back to normal size after the ice thaws. Do a little more research on it before you decide on copper. Either way, though, replace what you have now- you will get more pinholes.


Crescent
Premium
join:2003-01-22
canada
Reviews:
·Eastlink Cable
reply to jig

I had green spots, and about 5 pin holes in the house.
I looked further and saw more green spots.
Non of the multiple "main shutoffs worked" (I shut off 6 valves before the hot water tank that had all been added over time. When the tank leaked, I drained the tank, but 12 hours later, not wanting the drain hose going out the window, the tank filled again)

The past owners just kept adding shutoffs, all of them failed.
I think most of the failures of the valves was due to the copper inside the pipe breaking down to a "copper chip dust"? (my word, Best I can describe) and plugging the valves internally.

I decided to replace 1/2 the house at a time with PEX.
I was going to join up to the copper at the BEST looking copper pipe section, rubbed the pipe with a Scotch Brite, and the Scotch Brite turned wet!

I gave up on that idea, and pre-ran the other side of the house in PEX too, and did the change over, copper to pex in most of a morning.


Crescent
Premium
join:2003-01-22
canada
Reviews:
·Eastlink Cable

My new PEX setup, I also did not do the manifold thing.
I did it all in 1/2 inch PEX.

From the main shut off valve it followed the shape of a big letter "C" under the house.

Since PEX was so easy, I installed 3 more outside taps, a Laundry sink in the Garage, and 2 hot water garden hose fittings to supply the 2 places I use the pressure washer.

With the additional outside taps, I carried the main line back to the main shutoff, to a big letter "O" shape under the house.

Making the "O" shape I noticed a slight increase in water flow, but not significant.

The pressure valve was also replaced, increasing the size from 1/2 inch to 3/4. ($54) for the pressure valve was simpler than cleaning the probably 50 year old strainer.