Electrolysis?

Out There
Out There Solar Expert Posts: 96 ✭✭✭✭
in Solar Water Pumping #1
Gentlemen,
I've a new problem: My house was built in 1987 and the plumbing is distributed, after the pressure tank, via rigid, thin-walled copper. In the last two weeks I've had three pinhole leaks develop. I put temporary patches on the first two, then called in a plumber. He replaced the two pieces of tubing. On the pieces he took out there is an obvious but extremely localized erosion visible on the inside of the tubing and relegated to a tiny area around the pinhole. The spot of erosion shows the green patina of oxidized copper but this is not spread anywhere else on the inside of the tubing. Within a couple hours of him having fixed those two leaks, we sprung another.
The plumber has suggested electrolysis as the culprit. He didn't think the system was grounded. Upon my investigation, I DO find a ground wire securely clamped to the fitting where my pressure gauge and switch are located. This ground is connected to the 110 volt distribution panel's ground/neutral bar.
I have read where systems like mine, being subjected to dissolved minerals in slightly acidic water left sitting in copper over long periods of time can create - in effect - many small "batteries", which would seem to support the extremely localized nature of my "erosions".
Any thoughts?
Brian
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Comments

  • H2SO4_guy
    H2SO4_guy Solar Expert Posts: 213 ✭✭✭
    #2
    Re: Electrolysis?

    Try to find out if you have Chinese sheet rock. It was doing that type of thing to copper pipes IIRC in an article in the news. Do a search and find out more.

    Good luck and let us know!

    Skip
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  • waynefromnscanada
    waynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    #3
    Re: Electrolysis?

    Unfortunately, "thin wall" copper pipe tends to do this, particularly if the water is low ph or otherwise corrosive.
    Traditionally, for this reason, only thick wall copper pipe was used in home plumbing. The thin was stuff was only used in residential hot water heating systems that were sealed from the atmosphere and didn't have it's water changed.
    Some years ago however, due to copper's high price, the thin wall stuff became common in regular plumbing, and you are seeing the results.
    Yesteryear's professional plumbers would never recommend thin wall copper.
    Today, copper is more and more rare in new construction as new, very reliable substitutes are available.
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  • Out There
    Out There Solar Expert Posts: 96 ✭✭✭✭
    #4
    Re: Electrolysis?
    H2SO4_guy wrote: »
    Try to find out if you have Chinese sheet rock. It was doing that type of thing to copper pipes IIRC in an article in the news. Do a search and find out more.

    Good luck and let us know!

    Skip
    I took a look at this. From what I can tell, the Chinese sheetrock problem is evident from the outside of the copper tubing. Mine is only on the inside… and is very localized. The corrosion is happening in spots on the inside - completely out of sight until it breaks through and I have a leak. The outside of the tubing still looks new, it's just got a hole in it! I have five area of damaged sheetrock, now, because I've had to hunt down these leaks!
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #5
    Re: Electrolysis?

    Some thoughts:

    http://www.repairmyleak.com/about/failure-copper.htm
    Copper (Pitting) Corrosion
    There are many forms of corrosion, but pitting corrosion is most likely to culminate in pinhole leaks in copper plumbing.

    Pitting corrosion is the non-uniform localized attack of the wall of copper tube, pipe, or fittings initiated on the inside surface of copper water pipes. Usually only small areas of the metal surface are attacked.

    Pitting corrosion can be classified into three types:
    Type I
    cause: Hard Water
    Type I pitting is associated with hard or moderately hard waters with a pH between 7 and 7.8, and it is most likely to occur in cold water. The pitting is deep and narrow, and results in pipe failure.

    Type II
    cause: Soft Water
    Type II pitting occurs only in certain soft waters, with a pH below 7.2 and occurs rarely in temperatures below 140° F. The pitting that occurs is narrower than in Type I, but still results in pipe failure.

    Type III
    cause: Cold, Soft Water High PH
    Type III pitting occurs in cold soft waters having a pH above 8.0. It is a more generalized form of pitting, which tends to be wide and shallow and results in blue water, byproduct releases, or pipe blockage.
    Water Velocity
    When copper tubing is installed that is too small in diameter for the pressure and flow available, the resulting high flow rates can erode the protective coating creating areas of bare, unprotected copper. This effect can result in a high rate of corrosion wherever the protective coating is eroded.

    The greatest effect of velocity occurs where the water is forced to change flow direction, such as at elbows and tees, but excessive water flow rates can be damaging to the entire plumbing system.

    Here is a 2004 Maryland water company(ies?) report on a study of pin-hole leaks in copper plumbing:

    http://www.wsscwater.com/file/EngAndConst/InfrastructSystems/Study%20of%20Pinhole%20leaks%20Report.pdf

    In their report--They do not know is the simple answer. It appears that chlorination+aluminum solids are really hard on copper pipes. Electrolysis, grounding, lightning appeared to have no affect. If aluminum solids are a problem, I wonder of a whole house filter would help (nothing mentioned in report).

    If your leaks are on the hot water side copper, I wonder if it is the Water Heater Anode Rod... Some are magnesium and others are aluminum (or aluminum/zinc).

    http://www.waterheaterrescue.com/pages/WHRpages/English/Longevity/water-heater-anodes.html

    Call your water company and report the problem. Replace bad pipe (or re-pipe whole home). Use alternative materials.

    I have had issues where contractors (and homeowners) have used galvanized pipe in copper plumbing for the last 6" (instead of brass or copper). But the little I have seen that, the galvanized pipe is usually the loser.

    Water heaters (steel tanks) usually used galvanic isolation couplings (to reduce corrosion in the steel tank). Normally not used on the rest of the copper to copper plumbing system.

    Another cause of localized corrosion is the use of steel pipe hangers and Nailing Protectors (used under drywall over copper and electrical runs to stop drywall fasteners from causing damage in through stud piping/electrical) that rest directly against copper pipe--Need to have a piece of plastic insulation between steel and copper if there is physical contact.

    There was a change from Chlorine treatment use by water companies to Chloramine based water treatment in over the last decade or so. There are lawsuits in recent years claiming that the change to Chloramine has caused pin-hole leaks in copper piping.

    http://www.ocregister.com/articles/water-340682-leaks-copper.html

    That is what I have read about the issue... Almost makes me want to change to PEX plastic piping instead.
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • Dave Angelini
    Dave Angelini Solar Expert Posts: 6,891 ✭✭✭✭✭✭
    #6
    Re: Electrolysis?
    Out There wrote: »
    Gentlemen,
    I've a new problem: My house was built in 1987 and the plumbing is distributed, after the pressure tank, via rigid, thin-walled copper. In the last two weeks I've had three pinhole leaks develop. I put temporary patches on the first two, then called in a plumber. He replaced the two pieces of tubing. On the pieces he took out there is an obvious but extremely localized erosion visible on the inside of the tubing and relegated to a tiny area around the pinhole. The spot of erosion shows the green patina of oxidized copper but this is not spread anywhere else on the inside of the tubing. Within a couple hours of him having fixed those two leaks, we sprung another.
    The plumber has suggested electrolysis as the culprit. He didn't think the system was grounded. Upon my investigation, I DO find a ground wire securely clamped to the fitting where my pressure gauge and switch are located. This ground is connected to the 110 volt distribution panel's ground/neutral bar.
    I have read where systems like mine, being subjected to dissolved minerals in slightly acidic water left sitting in copper over long periods of time can create - in effect - many small "batteries", which would seem to support the extremely localized nature of my "erosions".
    Any thoughts?
    Brian

    Brian,

    I would look at the generator also. It sounds like you are offgrid and the generator could be defective. One neutral bond only correct?

    --Dave
    "we go where power lines don't" Sierra Nevada mountain area
       htps://offgridsolar1.com/
    E-mail offgridsolar@sti.net

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  • Out There
    Out There Solar Expert Posts: 96 ✭✭✭✭
    #7
    Re: Electrolysis?
    Dave Angelini wrote: »
    Brian,

    I would look at the generator also. It sounds like you are offgrid and the generator could be defective. One neutral bond only correct?

    --Dave
    Dave,
    I do believe there is only one neutral. In this state, ground and neutral are tied, so that's how I'm set up. How does the generator create this problem?
    Brian
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  • Out There
    Out There Solar Expert Posts: 96 ✭✭✭✭
    #8
    Re: Electrolysis?

    All three leaks have formed on the cold water side. We have also detected ferrobacteria in the well water, which thrive in an acid environment. The house was also unoccupied for over a year.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #9
    Re: Electrolysis?

    Disinfecting the well? Hot water through cold water pipes? Flushing pipes on a regulator schedule?

    http://www.lenntech.com/iron-bacteria.htm

    Beyond my knowledge.

    Good luck,
    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • Out There
    Out There Solar Expert Posts: 96 ✭✭✭✭
    #10
    Re: Electrolysis?
    BB. wrote: »
    Disinfecting the well? Hot water through cold water pipes? Flushing pipes on a regulator schedule?

    http://www.lenntech.com/iron-bacteria.htm

    Beyond my knowledge.

    Good luck,
    -Bill
    We've only been in this place a couple of months. I have disinfected the well, and that appears to be working, but no other maintenance. We're bathing and cleaning with the water, but are waiting to use it for cooking and other consumption until we have it tested - which is delayed because of the disinfection. Perhaps, when we test it, the pH will give us further clues. I've read that class M tubing has a life span of 20 - 25 years. I know it often lasts a lot longer than that, but this house is now 26 years old (Amazing, huh? Built-in obsolescence.). There is not a huge quantity of pipe. Pressure tank is in basement about 15 feet (horizontally from bathroom plumbing. Water heater connection is currently located about 5 feet horizontally and 6 or 7 feet vertically away. The water is plumbed about 20 feet (horizontally) across the width of the house where it supplies the kitchen and one extension of the cold water line runs another 10 feet to an outside wall penetration for a sillcock. I'm thinking of asking the seller to contribute to re-plumbing the house with PEX or CPVC.
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  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    #11
    Re: Electrolysis?
    Out There wrote: »
    I'm thinking of asking the seller to contribute to re-plumbing the house with PEX or CPVC.

    Did you get a home-buyer insurance policy ? Does it cover pipes? Re-plumb is the only answer, likely all the pipe came from the same batch, and the rest is likely to quickly fail too. Electrolysis would be localized to near any metal interfaces.
    I'd re-do it with PEX
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  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
    #12
    Re: Electrolysis?

    Look on the outside of the pipe for the makers name and other info. The name Wolverine was a brand found in the 80's to have a manufacturing defect that cause your problem.

    hth
     
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  • Out There
    Out There Solar Expert Posts: 96 ✭✭✭✭
    #13
    Re: Electrolysis?
    westbranch wrote: »
    Look on the outside of the pipe for the makers name and other info. The name Wolverine was a brand found in the 80's to have a manufacturing defect that cause your problem.

    hth
    Interesting! I'll look tonight (after work :p)
    Thanks!
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