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  • Heat exchanger cleaning

    I was wondering how often do you have to have you heat exchangers cleaned out. And what is the best way to do so.

  • #2
    I see no one else responded. I haven't done this yet. My plan is to continue using Neutra Salt to flush the system a couple of times a year as a preventative measure.

    Maybe next year or the year after I will take them off and have them conditioned at a radiator shop. I saw the inside of a heat exchanger that had very bad scaling and the subsequent reason for the the over-heat and blown engine.

    If you don't have a radiator shop near you, I would call Mack Boring since you are in Union. They may do it there or at least tell you of a good radiator shop.
    Bullish
    2002 28
    Volvo Kamd 44p's

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    • #3
      Every three years on my old hatteras i would pull them off, and soak them in muratic acid for about two hours. Afterwards i would then pressure wash them. Next make sure you get new gaskets before you install them. Not only would the engines run cooler but it would also reduce black smoke when i was coming out of the hole.
      I would also agree that if they are extremlly bad take them to a machine shop to have them bored out.

      To Kiln For
      Soldiers Creek, Al

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      • #4
        Another consideration is Rydlyme closed circuit circulation. Rydlyme is designed to be circulated on the salt water side of heat exchangers and has excellent application to our diesel engine SW loop. There are now inplace cleaning companies getting into the business of coming to boats and cleaning coolers in place.

        About 6 years ago the US Navy stopped pulling saltwater coolers for dippping in various acid tanks, roddings, brush cleaning etc. The success has been great and a "loop of coolers" as we have is even more efficient than a single cooler. I have made a cooler cleaning rig and will start my project in the spring. The process in a nutshell is a measured dose of Rydlyme and fresh water circulated through the SW loop. On a diesel the "loop" is pretty easy, you just have to have an inlet hose connection after the SW pump and a recovery container under the exhaust outlets. The mix is circulated with a impeller pump and the PH monitored. The beauty of Rydlyme for industry is that once nuetralized it is not hazardous material and can be disposed of in most sewer sytems (check your local laws). Rydlyme will not eat gaskets and long term studies have shown that the amount of copper it will take away from an alloy cooler is so minimal that it can be ignored and is no different than a dipping method in that regard. It will make short work of zincs but you need to replace them anyway. I was personally involved in the original testing for the navy and I can tell you that I went from a non-believer to a supporter of this stuff real fast. A shell will foam away before your eyes in a container of Rydlyme. A cooler packed with shells or clogged with calcium deposits will come out sparkling clean UNLESS the cooler is 100% clogged an ZERO solution can circulate.

        http://www.rydlymemarine.com/faq.html or Just Google Rydlyme and you will find tons of info not company based
        Last edited by Patriot; 01-09-2008, 05:18 PM.
        NIGHTHAWK
        2001 CC 28
        Yanmar 300's

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        • #5
          Patriot

          I spent a while on their website and read your post a few times over. Maybe I am not understanding your description of the procedure.

          The chart on their website gives the impression that you will need to perform the procedure constantly from an hour to several hours depending on the size of your heat exchanger. How do you plan to do this by using a collection container out of your exhaust?

          I was thinking of connecting two hoses to both ends of my exchanger leading into the same container with a pump connected to one of the hoses. This would allow the solution to be continuously pumped through the exchanger for as long as needed.

          Perhaps you can elaborate on your procedure. Thanks in advance.
          Bullish
          2002 28
          Volvo Kamd 44p's

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          • #6
            The amount of flushing time required is directly related to the degree of hard scale build-up. If you want to flush just a single cooler the process in my mind becomes more difficult than it may be worth. Let me expain:

            The key to any flush is to get circulation through the entire cooler on the sea water side. On large industrial or shipboard coolers we typically have zincs in the end bells of the cooler and the SW inlet and outlets are valved. In that kind of cooler configuration you simply isolate the cooler (close SW in and out), drain the cooler of seawater, connect your flush hose at a removed zinc threaded hole on the inlet side and one on the outlet side. You fill the cooler with the Rydlyme mix and circulate it.

            Now move to the configuration of pleasure boat diesels. You may or may not be able to easily to isolate the SW inlet and outlet of the cooler because they are typically hose fittings. You could of course take off the inlet and outlet SW hoses and use those nipples as your inlet and outlet points for circulation but many engine configurations using sharp radius molded hose can make that difficult. When you are done, you have completed one cooler and it probably was not much easier to do than pulling the cooler off the engine to begin with. Now consider that most marine diesels have multiple SW coolers. Things like the main heat exchanger, fuel coolers, lube coolers, intercoolers, transmission coolers and so on. Any one of those coolers where salt water is the cooling medium needs to be cleaned. Study your cooling loop flow (usually a diagram in the manual) and you will see that you have several coolers that will benefit from an "in series" flush arrangement inluding the all important intercooler. Flushing the entire SW loop from the inlet to the exhaust overboard now makes this all worthwhile because I need to disconnect only one point of entry and the exhaust outlet is the exit. Since you cannot flush through an impeller pump the inlet connection for flushing must be after the SW pump or you have to remove the impeller. On most engines there is a hose at the SW pump OUTLET, that is where you make your flush connection. The flushing loop works like this: the flushing pump discharge hose connects to the engine SW cooling pump outlet (one hose connection) then the flushing liquid will circulate through the entire seawater cooling loop in the sequence that your normal cooling flows and exit the exhaust. Although you could do this waterborne I won't due to not wanting to disconnect the exhaust hose and sizing it down to the flushing pump inlet. While you are on the hard however it becomes real easy you simply place a suitable container under your exhaust outlet. At the bottom of that container you have installed a pipe nipple that is connected to the INLET (suction side) of the circ pump. I have a five gallon bucket modified with a pipe nipple to garden hose fitting, a short legth of garden hose to the circ pump and then hose up to the engine connecting at the SW inlet (the engine pump's outlet). The bucket is filled with your mix, you start it and run it down to almost empty, refill with flushing liquid (water and rydlyme) and start again. On my engines the raw water side holds right about 5-6 gallons so once I get the first bit of liquid coming back out of the engine and flowing into my bucket I know that from there it is just a matter of getting the bucket level about 1/2 -3/4 full and then you have a "closed" loop circulation that can run while you drink beer and watch it. I can get this going on just about any engine in less than 30 minutes (it just sounds hard). The beauty is that you are only taking apart one hose joint to flush every cooler in your raw water loop. The initial challnge of course is to round up the right fittings for your engine hose size. Garden hose works perfect for Rydlyme as do any PVC fittings you need from Home Depot. I bought a high quality flushing pump at a marine store for about $120 (it's almost a twin of one of those fancy oil change pumps that sits on top of a pail as a kit) It is easy and it works. When you are done you just flush with fresh water for a while and then replace all the cooler zincs with new which I do every spring anyway. I will have both engines flushed and all coolers sparkling clean in 3-4 hours max. The flushing rig you now own has many uses. I also used mine to circulate RV antifreeze through 400' of PVC pipe that supplies my freshwater to the dock from the house as a winter lay-up. You basically have a bucket that when filled can pump liquid to anywhere you want. (I will never pump oil in this one however).

            On my Yanmars the raw water loop flows like this from the SW pump>Fuel cooler>Intercooler>lube oil cooler>fresh water cooler- all in series and all getting cleaned via one connection. Think of the time it would take to remove and clean all those coolers.......
            Last edited by Patriot; 01-10-2008, 08:42 PM.
            NIGHTHAWK
            2001 CC 28
            Yanmar 300's

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            • #7
              Why are you using a pipe nipple at the end of the intake hose at the bottom of the bucket? Why not just suck directly into the hose?

              Are you concerned about thouroughly catching the water out of the exhaust so the process can be repeated for over an hour? I guess you could add more mix to the bucket as needed during the process if their is some spillage.

              Thanks for the detail.

              I ran some Neutra Salt through my system in the Fall but that seems to be more of preventative solution, not a corrective solution. Your stuff seems like the right product for reversing the effects of scaling.
              Bullish
              2002 28
              Volvo Kamd 44p's

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              • #8
                ? For Patriot

                Patriot,
                Thanks For The Info. On Rydlyme, Looks Like A Great Product That I Am Going To Try.

                Why Can't You Use The Sea Water Pump To Move The Solution Thru The Salt Water Cooling System? I Flush My Salt Water Loop With Fresh Water Using A 3-way Sea Cock At The Salt Water Intake. I Also Winterise Using This Same 3-way. I Have A Fitting Attached To A Garden Hose That Makes The Job Easy !!!!
                (I Have Volvo 300's On My 2

                Anyway, Thanks For The Info. On What Looks Like A Great Product.

                CAPT. LC
                Capt. LC
                "Makai"

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                • #9
                  Bullish- I added the hole in the bottom of a 5 gallon bucket and installed a permanent nipple with a valve. Picture a 5 gallon bucket with a low point drain valve. You don't need that and could just suck out the bucket with a hose for sure. I just find it useful. I'll get you a pic in the next few days.

                  capt.lc- The Rydlyme flush is done without running the engine, thus you have no Sea Water pump. You possibly could set this up as a running flush but the idea is to circulate the flushing liquid in a continuous loop. The flushes you are doing now are "one pass" and expelled. I think you would have a temperature problem on a continous loop and that after a short time flushing liquid temp will continue to rise forcing you to abort the running flush. You also have a SW pump on your engine that pumps a lot more water volume than we really want to be dealing with here. It "could" be done I guess but I have never tried. The investment to make the rig and buy the fittings is under $150 including the pump which runs on 12V.

                  I am going to dig out the real trick to all this and get it to you guys. The approved US Navy procedure that flushing contractors must abide by strictly controls the PH of the flushing liquid (which is a mild acid). The benefit of the PH knowledge is two fold:

                  1. You don't run a stronger mix than you need to disolve hard scale. (saves you $$ and protects you from too strong a mix that will eat copper from the coolers)
                  2. The PH "monitoring" during the flush tells you when there is no more change of condition (Rydlyme has nothing left to "eat"= coolers are clean).

                  Sounds hard but it is elementary and the PH strips are dip style available at any aquarium or swimming pool supply shop. I have a copy of the navy PCP (process control procedure) coming from an old friend and will get it out to those who want it in a week or two.
                  Last edited by Patriot; 01-11-2008, 06:21 PM.
                  NIGHTHAWK
                  2001 CC 28
                  Yanmar 300's

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                  • #10
                    Thanks a lot for your time to explain thoroughly. I would love to see the process control procedure if you can provide in a couple of weeks.
                    Bullish
                    2002 28
                    Volvo Kamd 44p's

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                    • #11
                      Thanks for the help guys!

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                      • #12
                        I talked with Rydlyme a couple of days and their Product Manager sent me litterature. See attached.
                        Attached Files
                        Bullish
                        2002 28
                        Volvo Kamd 44p's

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                        • #13
                          One thing to remember is that Rydlyme will not eat organics. For example baby zebra mussels would have their little shells eaten right off but the mussel meat would be unaffected. You can dip your hands in this stuff and not be hurt but it will eat a clam shell right before your eyes. Hard scale is cleaned right to shiny metal, shells will be dissolved but a piece of eel grass may be be unaffected.

                          Flushed an entire firemain system (up to 10" pipe) on the USS Ticonderoga years ago as the system was clogged near solid with mussels. Ship was homeported in Pascagoula MS at the time. The shells were easily dissolved and very quickly by the Rydylme but hundreds of pounds of mussel meat was left to clean out, it wasn't pretty.......
                          NIGHTHAWK
                          2001 CC 28
                          Yanmar 300's

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                          • #14
                            simple solution to clean intercools

                            Greetings,
                            I've read all the posts and there is some great information.
                            But, it can get pretty complicated between the pumps, hoses, fittings, etc.
                            What I do every year, as a maintenence I run Muriatic acid thru the engines, salt water intake.
                            The whole process takes 10 min. just run thru a solution 50 acid/50 water, once you system is pressurized thru the system. Shout off the engine for 2 min. put a water hose on your salt water intake, flush with water. This cleans your whole system. I was told this method from a certifed Volvo tech. and this does work very well with very little effort.
                            Last edited by capt ernie; 01-16-2008, 09:23 PM.
                            Captain Ernie
                            Fintastic
                            28 CC
                            Cummins 4 bt's
                            Forked River Barneget Inlet, NJ
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                            • #15
                              Ernie-

                              What strength Muratic do you use? Muratic acid disposal falls under Hazmat. How are you disposing of it?
                              NIGHTHAWK
                              2001 CC 28
                              Yanmar 300's

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