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  • Leaky tank problem

    I volunteer at the local rail museum,where we have a General Motors E9 diesel passenger locomotive. It has two large engines, each of which has a coolant storage tank of welded, galvanized steel, about 3x3x3 feet. They have both developed pinhole corrosion in the bottoms and are leaking...the problem being, they are buried inside the engine compartment in such a way that they are not removable. Access is limited. There is a small inspection port in each. I'm scratching my head for a process of repairing these leaks. Any help would be appreciated!

    I'm thinking: needs to be repaired from inside? Would some kind of mastic or chemical work? (I know a guy who repaired a motorcycle gas tank with some kind of epoxy made for the purpose, poured inside as a coating --- is there a similar fix here?)

  • #2
    Clean it out and use a pourable silicone.

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    • #3
      I'm certain that there must be better ways, but I once plugged oil leaks on an S-10 oil pan using JB Weld from the outside. The pan started leaking at the spot welds where an internal baffle was attached. I drove the truck home in the evening, drained the hot oil, cleaned the outside of the pan with sandpaper and then laquer thinner, then smeared on the JB Weld before any remaining oil could seep out. Lasted the rest of the life of the truck, several years of daily use.

      As I said, there are probably better ways. How deep are the tanks? A head of water may exert more pressure on the repair than a few quarts of oil.
      Weston Bye - Author, The Mechatronist column, Digital Machinist magazine
      ~Practitioner of the Electromechanical Arts~

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      • #4
        Nalco's Adomite

        Leaking water seals on bottoms of the tank rings, of the huge gas storage tank in downtown LA, were sealed in early 1962 using a material from the oil and gas drilling industry. Evidently still working. Don't ask how we placed it.

        Look up Adomite, a clay like powder, which when wetted will settle to bottom and becomes quite hard, and impermeable.

        --G

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        • #5
          Agreed on the epoxy -(if that,s what it is,) used to patch leaky gas tanks, might be a problem getting it to spread around on a staitonary tank of that size, but it should work.
          A bit pricy but it is used a lot on antique car tanks, i think it,s around $60.00 a quart up here.
          The stuff i seen looks like thick aluminum paint.

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          • #6
            These folks make a product for that purpose. I've used it for three 6gal outboard motor fuel tanks. Worked well for me.

            http://www.por15.com/

            Though the por15 fuel tank repair process involves first cleaning it thoroughly with a product they provide, by shaking/sloshing; and application of the sealer also needs sloshing around inside. That's going to be a major problem in your situation.
            Last edited by lynnl; 12-07-2011, 04:42 PM.
            Lynn (Huntsville, AL)

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            • #7
              Just my opinion but I've found that regular JB Weld works a lot better than the 5 minute kind.

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              • #8
                Sodium Silicate (Waterglass) might be another option.

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                • #9
                  About 15 or so years ago I had a similar problem with an air tank repair I did. I welded in a new piece with a wire welder using flux cored wire. I was new to welding at the time and got some porosity. The fix for me was to clean the inside of the tank with inhibited acid which I obtained from a local A/C supplier and clean the metal and any rust to bare clean virgin metal. This acid is one that will eat rust & corrosion but not good steel and is used to clean water cooled A/C units. After thoroughly drying I poured in a thin epoxy called Steelflex made by Fasco http://www.fascoepoxies.com/products.html and rolled the tank around until the interior was completely coated. Since that time the tank never has any rusty color in the condensate I drain out and there are no air leaks. The pressure is limited to 130 PSI so I cannot attest to how this might work at high pressures, but it doesn't sound like you're dealing with that anyway.

                  Another option might be to use a fuel tank repair kit similar to Kreem Permatex, POR, etc). There are other similar products made by other companies but I can attest that the Kreem product is quite good. The kit includes an acid that cleans the tank (probably like the inhibited acid previously mentioned) and a sealer that adheres to the clean inner surface.

                  I believe the Kreem or similar solution would be more expensive than my first suggestion.

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                  • #10
                    Thank you, gentlemen, a lot of good information to start working on. Cleaning the internal corrosion in these tanks is a head-scratcher due to the limited access into the tanks and their size. I'll start persuing your leads, and thanks again!

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                    • #11
                      I had a leak in a 1" deep water pan for a air conditioner unit. Had to fix it quick... So I just wire brushed off as much of the corrosion as I could, And hit it with 10 coats of fast drying paint that was rated for underwater use (or somesuch!). Worked for years afterwards till I retired the AC unit.

                      Galvanized metal is not to be used as a water tank
                      Play Brutal Nature, Black Moons free to play highly realistic voxel sandbox game.

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                      • #12
                        This is a radiator coolant tank for a diesel locomotive, guess they made them that way in the 1950's. Part of the concern for a repair is there seems to be (although I can't find a spec) a huge flow through the tank. The input and output pipes are about 4 inches in diameter. I expect in a cubic yard of coolant there's a lot of turbulance, which makes a repair even more difficult.

                        I appareciate all the good thinking and ideas, gentlemen, I'll post a solution when we come up with one!

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                        • #13
                          Originally posted by macona
                          Sodium Silicate (Waterglass) might be another option.
                          Hmmm... really? Sodium silicate is water soluble. I use it after a calcium chloride wash to harden and seal cardboard mortars. The cardboard is impregnated with calcium chloride and then the sodium silicate wash causes an ion replacement reaction so I'm left with calcium silicate, which is insoluble in water.

                          Videoman - That turbulence can severely aggrevate the corrosion issue. Any debris, rust flakes, etc will get hammered around and can accelerate the wear issue. I think maybe this is referred to as corrosion-errosion accelerated wear? So, yes, the flow rate is an important thing to consider. Many of the epoxy repairs were meant for low flow rate applications and/or low temperatures (like in a fuel tank). I'm interested to hear how you manage to repair these.
                          Last edited by Fasttrack; 12-08-2011, 05:05 PM.

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                          • #14
                            Try a product called Belzona it is a industrial version of JB weld I have used it to repair some pretty worn parts on the ships I have been on.

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                            • #15
                              The inside of the tank must be quite dirty I assume that there is a drain plug hopefully large. My thought would be to insert a rotary water blasting head (Idon't think you can get one that can use a sand additive if you can that may be the way to go) in the inspection hole to get the most of it out.( the type they clean pipes with)Then fill the tank with baking soda and water (self tapping screws in the holes) and put a anode in push a current through it, you may have to do it a few times to clean it but I think it will do it. I used my single phase welder to put the charge through my drill press stand that was quite rusty made of second hand steel that was stored out side.It would have been in a tank about the same size as your tanks and I used about kilo of baking soda and about five hours of power on the lowest setting on the welder the only thing is, stay with in the duty cycle of the welder I got distracted and had to have a repair done. It cleans the steel back to gray when you water blast it clean put an inhibitor in the water to stop the rust bloom as the steel drys then your epoxy coatings or what ever you choose to use as sealant has good chance of sticking ---food for thought
                              Cheers Kiwi
                              Last edited by Kiwi; 12-08-2011, 06:17 PM.

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