Replacing or coating galvanized pipes?

Discussion in 'Plumbing Forum, Professional & DIY Advice, Tips & ' started by smcgowan65, Apr 8, 2006.

  1. smcgowan65

    smcgowan65 New Member

    Messages:
    4
    My sister lives in a house built in the 70's, and their pipes have finally gotten to the point where there's really low flow all over the house (it's a one story). We have been debating the efficiency of replacing all the pipes with copper, or just doing the epoxy sealer (not sure of the name, but the local radio fix-it guy here is all over it like white on rice). Our primary concern is the fixing part--if the pipes are replaced, we'll have to do all the cosmetic repair (green board, hardibacker, sheetrock, tile, paint, texture, and so on). The work sounds daunting. Has anyone out there replaced their galvanized piped with copper? How did it go? Was it horrible? Was the mess manageable? Has anyone else done the inside the pipe coating? What's that like? I have heard rumors of funky tasting water afterward. We are looking for a good solution to which we can contribute sweat equity, but not to the point of unreasonableness since we both have full time jobs.
  2. Well, here is the scoop; someday you will replace those water lines, it is inevitable. That system you are talking of would probably clog them up for good. That epoxy is mainly used for copper piping and most times they won't discuss what happens when there is a total blowout of the copper tubing in the wall or ceiling (they have to go in and replace a section like you would any other type of piping) and this is what you are trying to avoid to begin with.

    As with any water line system in a home there will be removal/patching of walls/ceilings/floor depending on the areas affected. In galvanized systems usually the last 3 fittings leading to the fixture usually clog up, cleaning/removing them would probably restore flow that is sufficient to operate the fixtures. Most galvanized vertical lines remain clear. Funky tasting water is probably flux; that can be avoided by proper installation without excess flux. Majority of people have full time jobs so your time spent would be around work. Do a section at a time, always connect to dielectric unions when reconnecting to galvanized until it is all removed.

    Do not flux up a run of pipe/fittings and not solder the connections right away. This can cause quality issues with the solder joints. I cannot figure out why people do this to begin with. :confused:

    If cost is a issue, I advise inspecting the last 3 fittings leading to the faucet/fixture; you'll see that they will be clogged most times.
  3. smcgowan65

    smcgowan65 New Member

    Messages:
    4
    Love the cowbell.

    So, just to clarify, we can replace the last three fittings and that should be good enough to restore water flow? I think my dad said that hot water was more reactive than cold (or vice versa--they're not my pipes; I only get involved in the "crisis" discussions at family dinners; and Easter is coming...).I guess what we're trying to decide is: do you do the "quick" fix, or do you just go and replace all the hot (or cold) water pipes? I am trying to get a feel for how much of a mess is involved in breaking through a tiled shower to replace all that galvanized pipe.

    The funky taste people complain about if AFTER they coat the insides of their galvanized pipes with the epoxy. The pipes are "blown out" (whatever that is) prior to the coating. I have heard that the blowing out can actually remove sludge which has blocked pinhole leaks in glavanized pipes, too; yet another thing to worry about. The whole epoxy system is running about $2300.....
  4. That is news to me that you can epoxy a galvanized line. How it can remove 85% blockages is amazing. When I have my first heart bypass I am going to tell my doctor about this technique.

    I would shut the water off, remove the supply line from the fixture to the isolation valve under the sink/toilet. Then, CAREFULLY remove the valve. If you are dealing with deteriorated galvanized feed lines the threaded part of the pipe is the weakest part; they can snap off easily if you are not careful. If the pipe leading out of wall is completely clogged, take it back to the next turn of direction. If that next fitting leads to a vertical pipe, that vertical pipe is probably in decent shape and worthy of reconnecting. This though is a "trial by error" procedure and you are trying to avoid the error part as much as possible. Whether you have the hands of trained plumber or the hands of a monkey, this piping can have weak spots in the threaded parts or a pipe can break that will lead you to the next in-line threaded connection. That can turn a small job into a large one real quick. Just think of the snowball effect.

    What is weird is I have seen either hot or cold lines clog up completely. I would think for sure the hot would be first to go but sometimes the cold and not the hot will be affected. I've done a great deal of galvanized to copper changeouts in my years as a plumber. Very rarely does any galvanized pipe stay in a home. It always eventually goes bad/restricts flow.

  5. If you can, read the small fine print in the contract about the guarantee and exclusions that this service provides. You will probably realize through very well written logic (lawyer speak of course) that you can't make a silk purse out of a sow's ear, and they know that their product can only do so much.
  6. Bob NH

    Bob NH In the Trades

    Messages:
    3,317
    Location:
    New Hampshire
    Let's Apply Some Logic

    You have low flow all over the house which you attribute to galvanized pipe.

    Galvanized pipe fails when the internal galvanizing (zinc) is eaten away by corrosion, and iron oxide and other precipitates build up in the pipe. That buildup is called "tuberculation". It can virtually fill the pipe because the rust takes up much more space than the iron it replaces.

    At the bottom of the page at the link below there is a picture of an iron pipe nearly closed by tuberculation. And that is a large pipe.
    http://plasticpipe.org/mi/water/index.php

    The only way you will restore the flow capacity in the pipe is to:
    1. Remove all of the tuberculation, or
    2. Replace the pipe.

    If you were to manage to remove the tuberculation, you would still have a rusty pipe. That is what the epoxy is for.

    HOWEVER; all of the REPUTABLE epoxy coating suppliers require that the steel be sandblasted to white metal before the epoxy coating is applied. That is not possible inside a water pipe in your house.

    The best they will do is run some acid through your pipe to remove enough of the rust to increase your flow, do something that they will call "coating" on the rust that remains in the pipe, and quickly cash your check before you notice that they didn't really solve the problem. They will do nothing about the joints that will fail more quickly because of the acid in the joints.

    Do yourself a big favor and replace the pipes with copper.
  7. Gary Swart

    Gary Swart In the Trades

    Messages:
    7,347
    Location:
    Yakima WA
    There's always a "new and revolutiontionary produce" that will (a) restore compression to a worn out engine, (b) melt hundreds of pounds of fat without effort, (d) rejuvinate rusted out pipes. Who needs a mechanic, a diet, or a plumber! We Americans are brainwashed to think everything should be quick and easy and can be found in a package or can. Please don't be suckered into this scam. Replacing some fittings might marginally improve the situtation briefly, but face the facts. You will have to repipe the entire house sooner or later, and more likely sooner that later.

    Galvanized pipes at one time were the only thing available. True, in time they would corrode and cut water flow, but it's all we had. Today, no one would even consider galvanized pipes for at least a couple of reasons. First, it would be far more expensive to pay the labor for all of the cutting and threading. Everytime I use black iron pipe for natural gas, I am reminded of this. Second, it would be just plain stupid to install pipes that will corrode shut in time.
  8. jimbo

    jimbo Plumber

    Messages:
    8,997
    Location:
    San Diego
    The system you may refer to is the Ace Duraflow. They sandblast the insides of the pipe, then flow in the epoxy.

    Was your house bulit in 1870? In these parts, they stopped using galv. in 1950. All copper after that.
  9. shacko

    shacko Master Plumber-Gas Fitter

    Messages:
    561
    Location:
    Rosedale, Md
    Galve. pipe

    Sounds bogus to me, you are going to spend $2300 to repair pipe that you will be tearing out in a short time? [You will be tearing it out!]. Bite the bullet now and replace. Use the $2300 for new pipe. Luck.
  10. Mikey

    Mikey Aspiring Old Fart, EE, computer & networking geek

    Messages:
    2,714
    Location:
    Central Florida
    Urban myth dept.


    Actually, you can make a silk purse out of a sow's ear: http://libraries.mit.edu/archives/exhibits/purse/index.html
  11. sjsmithjr

    sjsmithjr Geologist

    Messages:
    295
    Location:
    Knoxville, Tennessee
    Galvanized Pipes after 1950?

    A little off toppic, but sometime during the mid 60s (1966?) there was a shortage of copper pipe in the U.S. A lot of homes got built with galvanized instead of copper, and around the same time the plastic DWV industry was born.

    Also, some "old timers", much as it is today, probably never made the switch to copper and stuck with what they knew.

    -Sam
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