aluminum gas tank

Discussion in 'Boat Design' started by fishinAK, Jan 13, 2011.

  1. fishinAK
    Joined: Dec 2010
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    fishinAK Junior Member

    hey there guys. Is there anybody in the pacific northwest that knows of a good place or welder to get me a gas tank.

    I am putting a new deck on the ol olympic so I figured it was a good time to replace the tank as well. its not leaking yet...but it is 22 yrs old. I assume this is near the end of its life expectancy right?

    the best price in town seems to be $1000. Isnt that alot for a rectangle 80 gal tank? dimensions are roughly 60x18x18 inches.
     
  2. El Sea
    Joined: Aug 2006
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    El Sea Junior Member

    Here in Florida we normally quote at $10 per/gallon (+/-) for a tank.

    El Sea/L.C.
     
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  3. rasorinc
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    rasorinc Senior Member

    1 person likes this.
  4. Mr Efficiency
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    Mr Efficiency Senior Member

    Most cars have plastic tanks these days, maybe not a bad idea for boats either, they sure don't corrode, which alloy not uncommonly does.
     
  5. SolomonGrundy
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    SolomonGrundy I'm not crazy...

  6. michael pierzga
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    michael pierzga Senior Member

  7. fishinAK
    Joined: Dec 2010
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    fishinAK Junior Member

    hmm someone suggested a plastic tank. any thoughts on a below deck plastic gas tank? Or know where I could find an 80 gal plastic tank?

    Not to open a can...but any thoughts on alum vs plastic vs fiberglass gas tanks?
     
  8. Mr Efficiency
    Joined: Oct 2010
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    Mr Efficiency Senior Member

    Someone mentioned on this forum poultice corrosion of aluminium, this seems to be what kills a lot of them. So foaming-in may not be such a smart idea as a way to help anchor them in.
     
  9. tom28571
    Joined: Dec 2001
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    Location: Oriental, NC

    tom28571 Senior Member

    HDPE plastic tanks are very good but they do have a couple issues that may be important to some. They don't have baffles because they are made by rotomolding which apparently does not allow that refinement. Also they swell about 2% when filled which must be allowed for in the mounting. Otherwise they are great. Someone mentioned INCA as a source. They do have a big catalog but they are not available except in large orders so are of no use to us. Tempo and West Marine do stock a small variety of Moeller HDPE tanks though.

    When they fit the application, I think plastic tanks are the best for boats. No off the shelf tank offers the most efficient use of available volume unless the space is designed for the available tank. This is the biggest driver toward the use of custom metal tanks. I made my own fiberglass tanks until ethanol was forced on us. Now I accept a smaller volume of fuel that storebought tanks can offer. That is not all bad since ethanol gas does not last long and stale gas is less a problem with smaller tanks.
     
  10. Frosty

    Frosty Previous Member

    Bladder tanks, ---dont slosh because ther are always full, easy to remove even from a small hole. Will fit any size hull.
    Gas water deisel what ever.
     
  11. Downtown
    Joined: Dec 2009
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    Downtown Junior Member

    What about tying together a number of Moeller 50 gal tanks. 45" x 12.5" x 22"

    Could say four be tied in together.
     
  12. tom28571
    Joined: Dec 2001
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    tom28571 Senior Member

    Be careful how you do this. Just connecting multiple tanks by gravity feed connections can be a real disaster waiting to happen if one of the connecting lines has a leak. This is normally done with a transfer valve so that the fuel pump does the work safely. Have seen two tanks connected by a line from the bottom of each. A bright person would never get aboard such a vessel.
     
  13. Downtown
    Joined: Dec 2009
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    Downtown Junior Member

    So, you are saying that there is no safe way to put multiple tanks on each side of the bilge? My original idea was to design two aluminum tanks per side at about 100 gallons per tank for a total of 400 gallons. Each of the four would be around 48 x 25 x 25. What would be the best tank design considering I want to get as close to the original tankage as possible, given the fact that my opening is max 26" through the floor in the saloon.
     
  14. tom28571
    Joined: Dec 2001
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    tom28571 Senior Member

    Not saying there is no way to do it. Just that connecting fuel tanks with hoses that allow gravity feed from one tank to another is looking for trouble if there is a leak in one of the multiple connections. Four tanks is a minimum of 6 of these gravity leak problems. If you have separate fuel lines from the top of each tank and switch when necessary, it is considered a safe installation. That is what is normally done in both planes and boats. Calls for more attention to fuel management and balance of CG.

    Maybe some here have more direct experience with this situation but that is my experience and opinion. All my boats haven't collectively used that much fuel in the past 10 years.
     

  15. mark775

    mark775 Guest

    Absolutely correct (accept with diesel it is commonly done and works well. There is just too much risk with gasoline).
     
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