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Differences in Gas Tank Construction?

Discussion in 'The Garage' started by Pookster, Mar 31, 2005.

  1. Pookster

    Pookster 1/2 ton status

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    im having difficulty finding out what are the differences between a gas and diesel fuel tank- some had said that gas tanks are galvanized, and diesel tanks arent, and that diesel will react with galvanized metal...

    Anyone have any other information?
     
  2. dyeager535

    dyeager535 1 ton status Premium Member

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    All GM tanks are coated with *something* internally, although I'm not sure it's galvanized, it probably is.

    That's what you've got a fuel filter for, right? :)

    As a matter of fact, on other GM diesel applications (like the cars) the tanks had a "sump" for water. If the tanks weren't coated, they'd rust out from the inside in that location.

    I do find it hard to believe that diesel will have a problem with galvanized or any other coating. Have you searched the web just to see if it *is* some sort of problem with diesel and a certain plating or coating?
     
  3. RootBreaker

    RootBreaker 3/4 ton status Premium Member

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    well I dont know about that... however..

    I took 2 gas tanks from a diesel and put my float assembly in them and still use them....

    when I just went to inspection.. the guy opened the door on the bed and it says.. Diesel Fuel Only... then on the cap it says the same.. and the neck is from a diesel.... thus he looked at me.. but didnt say much... :D
     
  4. Emmettology 101

    Emmettology 101 3/4 ton status

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    So are you trying to use a "gas" tank in a diesel app?
     
  5. Pookster

    Pookster 1/2 ton status

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    Yeah, that pretty much my issue- I know it needs SOME coating, just not certain what. Its auctally a Gas tank (got it cheap) using it in a diesel application, filling with waste vegetable oil. I've seen some posts elsewhere of people developing tihs weird Zinc/ vegetable oil problems, and they all have specified something to the effect of zinc coated tanks will react.

    The best solution I have so far, is to use POR 15 tank coat on the inside. It is certainly easier to do it now, before it is full of fuel later. However, most people have also stated that a diesel tank is different from a gas tank. (LMC however states the same part number for the gas tanks for all fuel types)
     
  6. CyberSniper

    CyberSniper 1/2 ton status Premium Member

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    Well, zinc is copper-ish colored. All the tanks I've had apart are similar inside (diesel and not) but sometimes the diesel ones had sumps/baffles in them where gasoline tanks didn't get them until fool-injection.

    I, personally, would just flush the tank (duh) and then bolt the sending until and filler neck setup on to the tank and call it good. Worst case you have to change the fuel filter but I doubt you'll have a problem.
     
  7. Pookster

    Pookster 1/2 ton status

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    I thought zinc was just greish colored? (I could be wrong, all I go on is what I've seen on roofin nails, and I dont remember them being copper colored).

    Here are some weird stuff from a WVO in a galvanized tank

    http://community.webshots.com/photo/238505035/279030497QBaxZO
    http://community.webshots.com/photo/281868009/288484580BEwmnU
    There's some crap forming in there, obviously. its nothing that my filter couldnt handle, (and im sure, after time, all that stuff would get sucked into the filter, then I wouldnt have the problem anymore. Its just a pain in the ass to add water and liquid to a perfectly dry tank just to have to dry it out again, before a coating. The tank in th epicture is stated as being also galavanized- but not copper colored.
     
  8. CyberSniper

    CyberSniper 1/2 ton status Premium Member

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    Well, zinc is actually gold colored... and when you plate stuff it ends up gold colored. But galvanizing is more of an oxide with other metals mixed in. It ends up white. I know certain acids will eat zinc oxide and you'll end up with particles forming and stuff.

    I don't know, I've got a 1 class chemical engineering education.
     
  9. diesel4me

    diesel4me 1 ton status Premium Member

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    Galvanized ???

    I wonder if tanks are just galvanized with zinc,or if its a combination of stuff like "galvalume" steel,like my quonset hut is made of--its a combo of zinc,aluminum,and something else I cant remember!--maybe that would react with vegatable oils??..
    I always thought galvanized zinc coated steel was gray??--but I do know it turns yellow green when you use a torch or welder on it-(and so do you if you breathe the fumes! :blush: !)...

    I'm wondering why you dont use a plastic tank?-or 55 gallon barrell,plastic or metal?--I put a dodge tank in my 74 K20,no more rust or leaks!--A plastic tank from a dodge ramcharger was my friends "storage" tank at his junkyard to hold the fuel drained from junk cars and trucks--it was about 30 gallons,and pretty rugged..would plastic be suitable for diesel or WVO??..
     
  10. ntsqd

    ntsqd 1/2 ton status

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  11. dyeager535

    dyeager535 1 ton status Premium Member

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    Tank part numbers are the same gas or diesel.

    Straight out of the 1986 GM parts manual.
     
  12. Pookster

    Pookster 1/2 ton status

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    thanks a bunch!
     

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