Diesel tank leak

Discussion in 'Big Boats' started by cmonroe54, Jun 30, 2018. Add this thread to a FAQ

  1. cmonroe54

    cmonroe54

    Joined Jul 23, 2013
    20 posts, 4 likes
    Hunter 37
    Hunter '37, 1980 Cherubini

    The 42 gallon diesel fuel tank has just sprung a leak. I'm guessing I'm loosing about a gallon a day to the bilge. I'll, of course, clean up the bilge, but what's the best approch to the fuel tank? It's glassed in under the rear berth, form fitted and no way to remove it without putting huge holes in my boat.

    Please talk to me. I just spent a couple thousand dollars getting the power train fixed and my pockets all that deep. HELP!!!
     


  2. jssailem

    jssailem

    Joined Oct 22, 2014
    9,335 posts, 4,159 likes
    CAL 35 Cruiser
    US Salem, Moored Port Everett WA
    First Panic... no Do not panic... Begin with the simply steps. Look at the hoses. Are all the lines snug with good hose clamps. Are the fuel lines with fittings snug no leaking? Have you checked the fuel filter? When you had the work did the lines get removed or loosened?
    What is the tank made of? How old is the tank?

    You can wipe a clean rag along the hoses to find seepage.
     


    jon hansen likes this.
  3. svchickadee

    svchickadee

    Joined May 8, 2011
    184 posts, 26 likes
    ODay 25
    US Cambridge
    Have the tank professionally pressure tested.
     


  4. bobtigar

    bobtigar

    Joined Sep 29, 2008
    155 posts, 1 likes
    Morgan Out Island 33
    US Pompano Beach
    I used a jb weld putty that is specifically designed to patch fuel tanks. Worked like a charm on a pin-hole leak at the bottom of the tank on a weld line. Bob
     


    jon hansen likes this.
  5. cmonroe54

    cmonroe54

    Joined Jul 23, 2013
    20 posts, 4 likes
    Hunter 37
    I've checked the hoses, but I'll certainly check them again. All of the fittings for the hoses are at the top of the side of the tank, so gravity would be more likely to hold the fuel in the tank. Looking back on the last few months, the leak must have occurred during the time when the tank was low over the winter months. Maybe the leak occurred when I crawled on the top of the tank when the plywood cover was off to access wiring and it put pressure on the bottom sidewall of the tank. I can get to the entire top of the tank but the rest is epoxied into fiberglass. Is there any way to line the inside of the tank? I could cut the top out and access the entire inside. Or do I get a smaller tank to fit inside?

    I usually don't panic on things like this, but today it's tempting! I pray tomorrow brings a do-able answer.
     


    jssailem likes this.
  6. kloudie1

    kloudie1

    Joined Nov 6, 2006
    8,334 posts, 770 likes
    Hunter 34
    US Mandeville Louisiana
    On a buddy's H-33c, the aluminum tank had a couple of pinholes in the corners at the bottom and a lot of corrosion from the bottom up the tank wall for about 3/4".. On his tank, a pinhole repair would not have been good because of about 30 impending pinholes in other locations.. We were able to remove the tank and cut an inch off the bottom and welded a new bottom plate to the undamaged walls. If you can get at the top with enough room to work in the tank, you could open the top and clean the places where there is corrosion.. really clean.. use the epoxy putty bob mentions to plug the hole(s) and the worst impending holes.. then fiberglass the inside using epoxy.. has to be a good job to keep it from coming off inside there and really making a mess.... I suspect that if you had enough space to do that, you'd be able to get the tank out.. On the old 33, we were able to fish the tank out but it was quite a job to access it( under the cockpit floor) and then orient it to get it out the lazarette.. A small remote camera would help you make a decision b looking at the insides to see the extent of the internal damage.. Ya may opt for the big holes as best option..
    If it is poultice corrosion from the outside, whole 'nother problem, but may be easier to lift the tank and epoxy the areas..
     


  7. cmonroe54

    cmonroe54

    Joined Jul 23, 2013
    20 posts, 4 likes
    Hunter 37
    Looking at the tank from the front / bow, the top is flat, the front is flat, the starboard (toward the engine) is flat and a little piece of the aft is flat. The rest is a curved surface that follows the contour of my sloop. Ad to this that the tank was built into a rear berth with a closet and a door (parallel to the length of the tank) and the only way that tank is coming out is in little pieces! Or I can cut a HUGE hole in the side of my boat. :-O

    I'm going to see if anyone makes a fuel bladder that I could lay inside the old tank if I cut most of the top out. Or maybe a smaller hard shell that i can fit within the existing tank. I would loose a lot of fuel storage, but Jerry Cans could make up the difference, and I don't want to loose the rear quarter berth.

    Sources, anyone? I'm in the Delaware basin.
     


  8. kloudie1

    kloudie1

    Joined Nov 6, 2006
    8,334 posts, 770 likes
    Hunter 34
    US Mandeville Louisiana
    Does the closet/door come out by unscrewing a half-bazillion screws?
     


  9. cmonroe54

    cmonroe54

    Joined Jul 23, 2013
    20 posts, 4 likes
    Hunter 37
    All of the teak was glued together. I would have to take out the closet, the nav station, a teal wall and a fiberglass bulkhead!

    I just found a site that offers custom fuel bladders suitable to put inside the old tank!!! Ready Containment LLC from Palmetto, Florida. I’ll be calling them tomorrow!
     


  10. Rick

    Rick

    Joined Oct 5, 2004
    1,030 posts, 17 likes
    Hunter 420 Passage
    US San Diego
    If none of those ideas work, probably the best option is a replacement. A bladder that might leak or you could also look at this. http://www.tank-depot.com/product.aspx?id=1032
    They either have or can make a tank to fit your dimensions. It could fit in the shell of your old tank like a battery case. Not cheap but it beats a bilge full of diesel and a probable fine if it gets out somehow.

    Good luck
     


    Last edited: Jul 1, 2018
    shemandr likes this.
  11. shemandr

    shemandr

    Joined Jan 1, 2006
    3,983 posts, 923 likes
    Marblehead Skiff 14'
    US Greenport, NY
    Get that fuel out of the tank! You don't want it in the bilge and certainly don't want a sheen around your boat that the CG or other authorities could trace to your boat. That tank is toast. Look for another location for a tank. Do you really need 42 gallons? That's around 40 hours of motoring. Most auxilliary's use that in a season. There's another location. Seal up the current tank and consider it as buoyancy.
     


    justsomeguy and Rick like this.