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My Garn Corrosion Fiasco Part 1

Post in 'The Boiler Room - Wood Boilers and Furnaces' started by Rick Stanley, Feb 6, 2011.

  1. jebatty

    jebatty Minister of Fire

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    Maybe a question to ask is, given that Garn recommends best use of the Garn at supply temperatures of 140F and below, should a Garn even be considered when the primary application is continuous hot water supply above that? Certainly, firing until a desired higher temp is reached and then mixing down is not inconsistent with this, but trying to maintain continuous high temp is quite likely to result in the over-firing corrosion issues.

    A second question, if coatings are needed, why should this not be part of the implemented design provided by the mfr? Why hasn't the mfr dealt with this issue, rather than placing the 9% risk rate on the consumer? Would a person purchase another very expensive product knowing that she had a 1 out of 11 chance of a failed product unless the person spent considerable additional time and money to make the product safe to use "as intended"?

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  2. Rick Stanley

    Rick Stanley Feeling the Heat

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    That is exactly right, Tom. I have owned-up to my "action boo-boo's" that contributed to the corrosion issue. Didn't test early enough or often enough, took the sample wrong, didn't watch water level, and, of course, the boiling and all the chemistry that caused.
    The cause of the boiling, however, like you're saying, is another long list of "system boo-boo's". I boiled the thing over because I was pushing the temps to get less frequent burns and I overshot. The reason I needed higher temps is because I was/am keeping a large, poorly insulated, oil boiler hot enough to make dhw enough for two families with the coil that is in it. Big boo-boo. Like I've said before, I can heat this place, even in the coldest snaps with 140-150 degree water and dhw isn't an issue then. But the rest of the heating season I could run at maybe110-130 degree water with the radiation that I have if it weren't for the dhw issue. Chris told me that, the first time he was ever in my cellar. He looked at me and the oil boiler and said "you're gonna keep THAT thing hot??"
    Plus, the way I have things piped-up between the oil boiler and the hx is totally backwards. But I did it that way because it was easiest. Chris told me how to do it, but I did it MY way :-/ . And the list goes on. So, if I had it plumbed and controlled the way that was recommended to me from the start, I would burn less wood and never even come close to boiling temps and I think that's what a Garn is designed to do, run long and cool.
  3. DaveBP

    DaveBP Minister of Fire

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    I remember seeing a movie clip (I think it was Disney) demonstrating the concept of nuclear fission. This was back in the "duck and cover" era.

    Room with the floor completely covered with mouse traps, each with a ping-pong ball on its bail.

    Man tosses a ping-pong ball into the room and.... chain reaction mayhem! Balls flying everywhere in every direction.

    And then settled down to peace and quiet.

    Not sure why that memory came to me while reading over this thread.
  4. TCaldwell

    TCaldwell Minister of Fire

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    i think in any system designed today, one goal is make the system as efficient as possible, primarily using the lowest supply temp to satisfy demand , no mater how high a temp you choose heat the water. One you can heat it all at once, garn or any downdrafter with storage or continually heat it without storage. basically the garn could be equal to a slightly less output boiler with the same storage, pick your poison. Any boiler that you want to maintain a high supply temp will have to be fed more often, i don't follow the logic of the garn and 140deg water. As far as the corrosion, i honestly believe more awareness and the severity of consequences will reduce this problem below the 9%, coating or not. kind or reminds me of the econoburn - fan issue, at the end of the day when all the heads think solutions are found.
  5. bpirger

    bpirger Minister of Fire

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    Jim...Hold on a sec. I'm the guy who said the manual says 9% of Garn's have corrosion "issues". I never said, nor did the manual, that these issues led to boiler failure, So I think you might be gunning a little hard here against Dectra. Again, Dectra is resoundingly clear about the concerns of corrosion and becuase of the variability of all sorts of issues (like installation, like initial water, like water treatment regime, etc.) they clearly state there is no warranty against corrosion. Did that bother me? Yep. With such a huge outlay, for me anyways, I thought it was a little weak. But then I look at heaterman's experience and that of other Garn users and I feel like it is a solid product with a very solid history. I know of many standard oil boilers, pressurized, that failed within 20 years. Yet I hear of many Garns, open, that have been fully operational for 20 years plus.....

    So would it be nice to have a conformal coating to completely prevent corrosion? Sure. I think I'd rather have that on my truck and car, and everyone I will ever own, so that they don't rust. Good luck....it doesn't happen. Does that mean Toyota should be held accountable becuase my old '97 with 225,000 miles has a bit of rust on the frame? No. And in fact, the frame on that machine looks nearly new! Impressive indeed!

    So we can walk around an not pick on everyone about everything. I work with a software guy who does that...he has all the answers....everyone else's design suck....unit you ask him a hard question. Then all I hear is "I'm the software guy". So we all have to accept reality and the risks that go along.

    Now, from this thread, we can learn. Would it be nice to have Garn send out a clarification that says it is most ideal not to fire over 190 becuase that tends to break down water quality treatment sooner and may lead to increased biological concerns? Sure. I wish that was written and highlighted in the manual. Heaterman posted that here 1 year ago.....in the Easy Big Fellla thread from Rick.

    So as in many things, we learn, and we move forward. The beauty of this forum is the sharing of these experiences and knowledge. Truly amazing to have folks being so open here...and professional folks so willing to lend a hand as well. In many other facets in life, people might pursue litigation. Where has that gotten us as a whole? One place is it caused Garn to shut down their forum....I'm sure they were afraid of comments made there and liability due to them.

    Perhaps everyone here should always post a diclaimer, indicating they are not responsible for trying to help another out....
  6. Como

    Como Minister of Fire

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    I am not aware of any boiler manufacturer, or radiator manufacturer, or pump manufacturer who would warranty this sort of item.

    It would be similar to a Car Manufacturer warrantying the consequences of bad gas or oil, not within their control.

    The more common issue in hot water systems is scaling due to hard water, that is not covered either.
  7. jebatty

    jebatty Minister of Fire

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    You make your point well. Thank you for doing that. On the one hand I try to think of remedies to prevent the issue, and on the other the pictures that Rick posted raise an OMG response. Comes from a long background, not relevant here. I'll bow out of this thread.
  8. TCaldwell

    TCaldwell Minister of Fire

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  9. Holley

    Holley Member

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    I am grateful Rick took the time to document and post his corrosion issue and how he corrected it.

    When I first saw Rick's photos he was well into the process of cleaning under Mike's (Precision Chem) guidance. I was upset at learning that Mike had concluded that boiling the unit had been a contributing factor to the above water line corrosion. A year earlier I had told Rick that a boil resulting from an overfire was mostly a nuisance to be avoided... that if it happened once he was unlikely to do it again as he would learn the characteristics of his system. I think I suggested not reloading at over 180 as a starting guideline.

    I was particularly discouraged when Rick told me that he had a bio test done just before discovering the bacterial corrosion and that it had come back clean! We recommend twice a year visual inspection and water testing and we send reminders out with the belief that that schedule will head off any serious corrosion issue. I spent quite a bit of time on the phone with both Rick and Mike trying to understand what had gone wrong here. Like Rick I couldn't get my head around the negative bio test. I now believe I understand it, but I'll get back to that.

    Corrosion is about the only way a GARN can be damaged. The owner's manual talks at length about different types of corrosion issues and the need for water testing and visual examination of the tank. The type of bacterial corrosion above the water line that Rick experienced after boiling is not common. Dectra is very forthright in the manual about the potential for and causes of corrosion issues. If over-firing and boiling had been understood to be a common cause of the type and degree of corrosion Rick experienced, the manuals would have addressed it. Common or not, the newest manuals now do address it.

    The new digital GARN controls have been shipping for about month or so now. The new control has the following language on the front cover:

    Notice: DO NOT OVERFIRE! If the tank temperature exceeds 200 degrees F or steam is visibly discharging from the overflow pipe or the manhole cover – you are OVERFIRING. There is no danger of explosion. However, higher temperatures significantly increase water loss from the unit and may initiate moisture damage within your building or shed. Steam as a result of over-firing may significantly increase corrosion.

    Every new GARN is now shipped without water treatment chemicals, but with a water test kit. The owner is instructed to submit a water sample before filling their tank. Chemicals will not be shipped until that sample has been received and processed. This allows Precision Chem to make individual adjustments for unusual water issues, to get the owner into the testing routine and into Precision Chem's data base.

    Additionally, in our territory emails or postcards are sent twice a year reminding GARN owners of the need to maintain testing. The GARN owner's manual devotes several pages to the potential for corrosion and the critical need to maintain testing and good water chemistry. However, for some reason only about 1/3 of GARN owners avail themselves of the testing program, 2/3 do not! I'd guess that compliance among Hearth readers is much higher

    I had a phone call the other night from a GARN owner in New Brunswick who suggested that if a GARN is not going to be fired for several months fill the GARN unit to the manway ring thus fully wetting the top surface inside the tank. Heaterman then made the same suggestion. The information that Heaterman posted in #89 clarifying the over-firing issues was really good and I'd suggest that every GARN owner print it as a reminder.

    As to that reference in the manual relating that 9% of GARNS have experienced a corrosion issue, I'm told that that number is high and out of date. Apparently in the 80's environmental concerns eliminated many earlier water treatment options and until safer treatment methods were developed there were industry wide boiler corrosion issues. That 9% reflects those years. As bpirger pointed out that statement also does not mean that those 9 out of 100 GARN units were destroyed.......it means they experienced a correctable corrosion issue.

    I mentioned earlier that I was really troubled that Rick's bio test, done just before his visual assessment, had failed to detect contamination. After re-reading Rick's post I realized that he had drawn the water sample from a point in his basement 170 feet from his GARN and that the circulator had not been run since the previous heating season. The water that Rick drew was pretty much isolated from the soup that was brewing in his GARN so now the clean test doesn't surprise me. It also reinforces the need to collect the sample through the manway and do a visual check at the same time.

    Finally, I never cease to be amazed at the volume of collective and supportive knowledge that exists in this forum. Hopefully, we have all learned much more about water chemistry, biological contamination and corrosion as a result of Ricks experience and this discussion. Thanks to all of you.
  10. brad068

    brad068 Feeling the Heat

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    Just thinking out loud here.

    Bio contamination possibilities. What happens when we let our garns shut down for the season? First, the water keeps cooling down slowly. What happens to water when it cools- it shrinks. So what is going to replace that volume once occupied by water? Air. And where is that air drawn from? Up the overflow tube.

    Depending on what/where you boiler room is, that air could be laden with all kinds of bacteria.

    This cycling process is constant during the heating season but the high water temps neutralize any organics I'm thinking.

    So do you guys think that we may need some sore of filtering device on the overflow? Or just make sure when boiler is shut down AND cooled down, fill it up till it over flows?
  11. Singed Eyebrows

    Singed Eyebrows New Member

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    Chris, Why can't the Garn be coated on the inside to protect against damage? Owners have quite a few hoops to jump through & if there are mistakes of any kind there is no warrantee. This boiler was engineered out mechanically/function wise. With a decent coating maybe some of the draining/testing, testing/draining could be eliminated, Randy
  12. TCaldwell

    TCaldwell Minister of Fire

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    also check out www.scalefreeintl.com In either case, proper cleaning, sandblasting is required to insure product adhesion, as asked in earlier thread at the very least if garn coats the bottom of the tank, so scale and bacterial corrosion don't adhere why is the top third of the tank not also coated above the waterline to combat rust at the same time? maybe steve or chris might know? Maybe there is a good reason for not, just seems a reasonable thing to do at the same time. the scale free is very interesting also requiring no water treatment .
  13. Rick Stanley

    Rick Stanley Feeling the Heat

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    I wish we could get Mike from PrecisionChem into this discussion because Chris and Steve and Dectra and all of us rely on his say-so. But I remember talking with him about this coating issue and there was some difference between "above/at" the waterline versus "below" the waterline that made it a not-good idea to coat the top portion of the tank.
    But maybe we were not talking about Dectra changing their manufacturing process but rather, considering trying to clean-up my tank and coat it with something. I can't remember. But there was some snafu related to coating above and below with the same stuff.
  14. heaterman

    heaterman Minister of Fire

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    Regarding tank coatings............

    These are my thoughts and my thoughts only.

    I would guess that there is also a flip side to coating the tank and that is the increased risk of another type of corrosion, which is called "under deposit corrosion". This occurs when an area of the coating becomes compromised and allows water to contact the surface metal. What happens in simple terms is that the corrosive action becomes concentrated on that one spot rather than being spread throughout the entire metal surface. The effect is not much different than if you took a 1/4" bit and started drilling on the steel in that spot. The vast majority of the tank will remain intact but a hole is a hole no matter what. That being the case, coating the tank is not a 100% cure all and end all solution.

    Another factor from a manufacturing standpoint is cost. A Garn is already in the upper range of pricing in the market and adding the cost of surface prep and coating would make it higher yet. Given that the product is fairly low volume, each unit is virtually hand made so it would be impossible to get any economies of scale or production line savings ala Central Boiler and others like them.

    I would also think that given the outstanding track record of Garn in terms of longevity over the 30+ years they have been manufactured, the benefits of coating would in a vast majority of cases, be outweighed by the costs and risks entailed by coating the tank.
  15. heaterman

    heaterman Minister of Fire

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    Regarding Mike or even Martin entering this conversation......Knowing both of them to some extent, I have no doubt they would love to jump in here and help people understand all the facets of water chemistry and how it interacts with metal. The sad fact of today's world is that there are many in the legal profession that circle sites like this just looking for something to attack and line their pockets or ego. In addition, there are some who will take an incident like Rick experienced and turn it into a personal vendetta against a company or product. (Again Rick, you deserve a huge pat on the back for the honest and forthright manner you presented this) That being the sad state of affairs we find ourselves in, I don't think they or any other manufacturer would jump into something like this.
    I'm aware of another heating site that had manufacturers factory level techs posting on it and it was wonderfully refreshing to be able to soak up all the internal knowledge they offered. The sad fact is that a topic came up where the manufacturer was attacked much the same as some of the posts on this thread and it became a public trial of sorts right on the www. After that experience on the website, all the manufacturers left, not just the one who was attacked. The site has since also lost a lot of the contractors and engineers that used to hang out there and it's value to me has diminished to say the least.

    Heck, I would dare bet that some of what I have said could be used against me in a court of law, but I don't have all that much to lose so they can have it if they want. I'd rather learn and help others learn than worry about all the what if's.......
    I'd probably feel differently if I had a whole company and my life's work tied up in my product.
  16. Fred61

    Fred61 Minister of Fire

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    I have a question. In one of the posts above someone wrote in capital letters "DO NOT USE CHLORINE" and I would like to know why. Back at my old place I had a well drilled with 20 feet of casing. Since the static level was at ground level, there was about 15 or 16 feet of casing that contained water. I ended up with a rust situation and the drilling engineer told me it was bacteriologic contamination. I was advised to add chlorine bleach to the well. It worked! 24 years later the water was still clear of rust. Why didn't it re-infect in the following years?

    I don't believe chlorine will last 24 hours in an open system such as with a Garn. It will gas out quite rapidly whether heated or not. You guys with hot tubs know how long it lasts.

    Heck, when I lived in town and was hooked to the municipal water supply, the water was so laden with chlorine I could wear a pair of dark blue trousers in the morning, go home and wash them and end up with a pair of light blue ones for the evening.
  17. steam man

    steam man Minister of Fire

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    I've had years of boiler water testing, operations, and maintenance. This problem only illustrates the need for proper maintenance even when the boiler is not in firing season and it really isn't that difficult. The Garn issue makes me think of trying to maintain my pool more than a boiler. I would love to have one of those monsters down in my basement.
  18. steam man

    steam man Minister of Fire

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    The short answer: At elevated temps chlorine is bad news. It is highly reactive. Salts will form and cause corrosion.
  19. heaterman

    heaterman Minister of Fire

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    Different animal completely. Being that the water in a heating system is "captive" so to speak as opposed to constant fresh water running through pipes in the case of a well. It's standard practice to chlorinate a new well as the well itself has been exposed to air and contaminants on the bit or well tools. Once it's flushed out, the chlorine and residuals of it are gone and being that the well is sealed no further issues should occur.

    AFA chlorine in pools is concerned, there's a good reason everything is made of plastic or fiberglass. Same with heat exchangers used for them. Stainless and even titanium are standard equipment and that should tell you something about the corrosive nature of chlorine.
  20. sdrobertson

    sdrobertson Minister of Fire

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    This post is a excellent one and I also want to thank Rick for starting this. This morning I took a water sample to check for "floaties" and I'm happy to report to see nothing in the water sample that settled out. I have a closed system but I would have never check this without this post. I had no idea that "things" could grow in a boiler system. Thanks again to everyone.

    **EDIT**I forgot to include this......Even after reading about Rick's problems, I would still love to have a Garn!!!!
  21. brad068

    brad068 Feeling the Heat

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    What I would compare it to is back when the auto industry came out with this great undercoating _____ armor?

    The product was great at holding its self together but would let loose off the metal it was coating. It would then create a perfect pocket to trap moisture ,salt, sediment, between the coating and metal which in turn ate the metal right away (Replaced a few ford ranger spring perches).

    Its great if it will stay in constant bond with the metal but once it starts to let loose you could be in big trouble.
  22. Singed Eyebrows

    Singed Eyebrows New Member

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    If this really is a problem or not will probably be apparent soon as Garn owners carefully monitor their boiler insides. Hopefully the OP's experience was just a fluke, Randy
  23. bigburner

    bigburner Feeling the Heat

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    I researched tank linings before my project. Had the factory rep come out and offer some coating ideas all which were crazy expensive. The required metal prep would be almost impossible to do inside a garn best quality of sand blast. Anode and good water treatment I think is the key, the above water line areas still have me puzzled, it's like a rain forest in there. [warm,moist,dark]
  24. Fred61

    Fred61 Minister of Fire

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    What would an ozone bulb do to reduce bacteria?
  25. DaveBP

    DaveBP Minister of Fire

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    I believe ozone might be even more corrosive than chlorine.

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