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Early 80's fuel tanks

Discussion in 'Post Yacht' started by strongfinish, Nov 5, 2016.

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  1. strongfinish, Nov 5, 2016
    #1
    strongfinish

    strongfinish Member

    Joined:
    Jul 23, 2016
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    Location:
    NC
    My survey was postponed until this Monday but I wanted to enquire about the "leaking fuel tanks" issue that some say have plagued the 42's. This is an '82 42 with a fwd tank that's leaking. Owner replumbed the lines to draw strictly off the aft tank, a mere 250 +/ - gallons. A few questions so I can begin the process of replacing the fwd tank.

    1. Was there an install issue that resulted in these leaks? I have read through every thread here related to leaking tanks and it seems it varies from fwd to aft, the aft typically from a leaking cockpit floor. Does the fwd tank mounting platform need to be raised to eliminate a reoccurrence?

    2. Did the 42's all have a standardized capacity? Any chance someone knows the fwd tank dimensions? I realize I can pull it from the plate Monday, I'm researching tanks to decide on poly vs aluminum and possibility of locating a used tank/maybe from a recent storm damaged vessel.

    3. The threads I've read discuss fwd/aft tank transfer and the issues that have accompanied the pumps/valves, etc. Being I will install new plumbing, would there be an "ideal" means of plumbing the system to make the system most efficient.
  2. Capt J, Nov 5, 2016
    #2
    Capt J

    Capt J Senior Member

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    Aluminum fuel tanks have a useful lifespan of 15 years, MAYBE 20 if they're in a dry location. You have a leaking fuel tank and you want to put a used fuel tank in??? Are you crazy? First off, finding one that fits is next to impossible. An Aluminum tank is usually $7-8 per gallon. I would try find a good fiberglass guy that can fiberglass a fuel tank into your boat.......
  3. My Affair, Nov 5, 2016
    #3
    My Affair

    My Affair Member

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  4. baltimore bob, Nov 6, 2016
    #4
    baltimore bob

    baltimore bob Member

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    Atlantic Coastal Welding built my replacement for my aft tank. I beg to differ Captain J, aluminum will be quite long lived if properly installed and yes, kept dry.
    new tank 1.jpg
  5. SeaEric, Nov 6, 2016
    #5
    SeaEric

    SeaEric YF Historian

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    out on the dock
    Both of those tank builders are in NJ. They probably already know the dimensions of the fwd tank in an early 80's 42.
  6. shawn, Nov 7, 2016
    #6
    shawn

    shawn New Member

    Joined:
    Feb 13, 2006
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    Location:
    old saybrook ct
    Had to replace mine in a 77 both tanks were black iron. The aft tank was leaking from the top weld and where the chair was. Layers of metal would come off. The front tank had chew marks on the side. I have seen the same with the Aluminum on the 42 and 46 with chew holes in the side and bottom. Too pull the front tank you will have to get the gen out and take the inercoolers of the engine. You will be able to lift the front of the tank and pull forward, at this point you will have to lift the back side. Mine I had to cut the floor 6in and the tank came out. The aft tank (if you are doing one I would do both) If you cut the stringer between both tanks which Post told me to do you can pull the aft tank through into the engine room and out it will go. Post said its better way than cutting the cockpit floor you will have to re-tab the stringer when you put the aft tank back in. I have done this on several Posts.

    Guys with the older Posts right up to the mid 80s keep your eye on this, you don't want 200gal of fuel over the side.
  7. baltimore bob, Nov 8, 2016
    #7
    baltimore bob

    baltimore bob Member

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    I have another theory on the tank failures. On my 1975, the fuel tanks are in a containment separate from the bilge. The owners manual suggests you leave the drain to this compartment plugged to contain any fuel leaks. The down side is, if you get any water in there for whatever reason, the bottoms of the tanks will be subject to corrosion. When I complete my tank replacement project I think I will leave the plug out permanently.