Gas-Resistant Rubber Grommets?

Discussion in 'Motorized Bicycle General Discussion' started by moronic_kaos, Sep 24, 2010.

  1. moronic_kaos

    moronic_kaos New Member

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    Got a weed whacker tank mounted up to the bike. Relatively low-profile & hidden compared to the stock tank that comes with the kit and has a tendency to collide with my knees (not to mention, seems to fit very loosely on the frame).

    The only problem with the system is that the hole for the gas to go through was on the wrong end of the tank because weed whackers use a 2 or 3 line gas system so they can pump gas through in any direction, unlike our MBs. So I drilled a hole in the bottom of the tank & stuck a grommet in there and the line through that.

    It works great for about twenty minutes or so, but the grommet expands as if it were a sponge, gets very brittle, and cracks along the edge of the plastic hole. Then I just get a big mess.


    I've been to the following places:

    • Home Depot
    • True Value Hardware
    • Lowes
    • Tractor Supply
    • Autozone

    All of which do not sell a rubber grommet rated for gasoline. Anyone know where to get one? I've found them for sale online, but they want in excess of 15 dollars which seems ridiculous for something so simple & tiny.
     
  2. BarelyAWake

    BarelyAWake New Member

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    To only compound the problem, you're not just looking for a gasoline resistant grommet, but an alcohol resistant one as well due to the ethanol content in today's fuels ... wish I could help you, but I'm suffering from similar problems - as are my marine technician friends & many others I'm sure :(

    Aircraft Spruce & Specialty is a helpful company I called a few times when I was playing with ultralights, they've alcohol resistant fuel line readily available: BING ALCOHOL RESISTANT<br>FUEL LINE from Aircraft Spruce and as many ultralights and experimental aircraft use plastic tanks and grommets they may well have what you're looking for - just not in their online catalog... I'd give them a call.

    As anything for "aviation" is subject to a serious price markup even if not FAA approved, get a part number & shop around ;)
     
  3. 2door

    2door Moderator
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    Check your local Yellow Pages for a supplier of seals/gaskets and 'O' rings. There are several types of rubber-like compounds which are gasoline/alcohol/solvent resistant. Viton, comes to mind as well as others. There are teflon seals and 'O' rings which might fit your purpose. Good luck, let us know what you find.
    This is a Denver company but most major cities will have a similiar supplier> http://www.rocketseals.com/
    Tom
     
  4. Kevlarr

    Kevlarr New Member

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    Check lawn equipment dealers in your area too, they'll have a much better selection of what you're looking for then any of the other places you listed.
     
  5. r00t4rd3d

    r00t4rd3d New Member

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    Check your local ATV/Dirt Bike/Jet Ski shop. They normally have stuff like that or can get it. Neoprene washers will work with gas too.


    Or the redneck method :

    Cut a thin slice of gas line and use that for a washer/grommet/oring. Its what I do.

    :)
     
    #5 r00t4rd3d, Sep 24, 2010
    Last edited: Sep 24, 2010
  6. Dan

    Dan Staff
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    "Just for now", 2 days ago I cut the tip off a chemical resistant rubber glove finger and wrapped it over a steel washer. Not suggesting it but has worked just for now. (read until it fails and I have to fix it, lol)

    Was wondering, would nylon washers work? I am guessing if they did, you would see em used a lot. Will soak one in gas and check. Easily found an' cheap.
    Purty cleaver R00t. Gonna try that


    .
     
  7. r00t4rd3d

    r00t4rd3d New Member

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    Squeeze the fuel line in a vise then slice it even with a razor blade. You can make a pile of them in no time for a fraction of the cost of actual rubber washers.
     
  8. moronic_kaos

    moronic_kaos New Member

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    I couldn't see a washer ever working, since it would have no way to hold itself to the tank. The grommet has that groove in it that fits perfectly into the hole in the tank...
     

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