Modified fuel tanks

Discussion in 'Motorized Bicycle Welding, Fabrication and Paintin' started by Long&Black, Dec 3, 2008.

  1. Long&Black

    Long&Black New Member

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    I've been debating modifying the fuel tank that came with my Chinese kit.

    With the look I'm going for on my build the lip around the stock tank just doesn't work.

    I was thinking about cutting/grinding down the lip and tacking the halves back together with the MIG then brazing everything shut.

    Has anyone done this?

    I tried using the search and found nothing. Just curious what kind of luck folks have had if they've gone this route.
     
  2. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

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    You could always fill with body filler and make the tank have a wider look.
     
  3. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

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    I'm working on a "cover" for these right now.
     
  4. jasonh

    jasonh New Member

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    I don't see a reason why it wouldn't work, as long as you get it welded up well. Might want to use some gas tank sealer after welding just to be safe.
     
  5. Long&Black

    Long&Black New Member

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    Jason,

    I figured I would grind the lip down around the tank then zap the halves together and then braze the joint.

    I just wonder if this metal will withstand the heat without warping/deforming badly.
     
  6. misteright1_99

    misteright1_99 New Member

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    Here is a thread to look at. Terry didnt cut the tanks in half, but Im pretty sure he rewelded the filler necks, and the old holes, once he changed the location, so maybe he can answer your question reguarding wheter the metal will or will not stand up to welding.........

    http://motorbicycling.com/f15/new-dog-town-803-2.html
     
  7. bumleg

    bumleg New Member

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    imho tig welding or soldering would be better ,less heat generated.

    i tried to brase an old motorcycle tank once and pretty much made a mess of it.
    i needed a ton of filler to straightan it out afterwards, also the metel seemed more brittle afterwards.
     
  8. Long&Black

    Long&Black New Member

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    Solder...hadn't thought of that.

    I have a bunch of silver solder here - that would do the trick.
     
  9. Technocyclist

    Technocyclist Motorized Bicycle Senior Technologist

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    solder tends to break apart due to vibrations... better you use some brazing... or electric welds...
     
  10. jasonh

    jasonh New Member

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    I seem to remember seeing a gas tank repair video. I think they welded it, then filled in the pinholes and whatnot with silver solder. I'll have to see if I can find it.

    edit: ok, they used bronze first, then went over it with soft solder to fill the pin holes. This is part of a series of videos from KBS coatings on gas tank repairs.

    Repair video (repairing starts at about 3min):
    YouTube - KBS Coatings - Gas Tank Sealer - Part #2

    All their videos:
    Videos - Demonstrating How To Use KBS Coatings - Stop Rust
     
    #10 jasonh, Dec 5, 2008
    Last edited: Dec 5, 2008
  11. trackfodder

    trackfodder Member

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    You can always stick some "chrome" door molding around it. Personally, I am ready to empty my shed until I find the Hodaka Ace 90 with the peanut tank on it and put the regular chrome tank on the Hodaka. Darn, as I write this, the Hodaka engine sounds like a potential bicycle motor. It even slopes like the "Harley" with the Whizzer and Monark spring fork. God it is cute. It might be skinny enough to put a peddle crank behind, or I could use a longer straight shaft and removable crank arms like a lightweight. Barring that, the Motobecane is another possibility KWrotfl
     
    #11 trackfodder, Dec 5, 2008
    Last edited: Dec 5, 2008
  12. seca40

    seca40 New Member

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    When I did Jesse James schwinn tank I used the kit filler cap. I didn't notice that it warped but I think it would be very difficult to weld all the way around without burning a hundred holes in it. The material that the schwinn tank that is only supposed to "look" like a fuel tank was easier to weld on that the HT tank. I'm not a very good welder but even so I think brazing would be the way to go. I think Bikeguyjoes' I dea of using bondo to hide the seam is a good one. The weld on what's left of my HT tank is ~ 1/4 " wide. You could remove maybe half of the seam then fill the rest.
     

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  13. trackfodder

    trackfodder Member

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    I took my own advice and stuck chrome car door molding around my tank. If you like bling it doesn't look too bad and I already bumped it with stuff that would have screwed up the paint. I unearthed my peanut tank and it has rust holes in the bottom. However, the chrome Hodaka tank looks pretty neat on my yellow 3-speed with the 5-1/2 Jiang Dong. I have a problem with the gas tank on the motor. The fuel gauge self-destructed and a subsequent rubber expansion plug swelled, so I may pull it and use the Hodaka tank. It already has chrome fenders , so it is color co-ordinated. Keith Williams.boogy1a
     
  14. Long&Black

    Long&Black New Member

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    I think what I'll do is get a motorcycle tank and work with that.

    I'm going for a specific look/style with my build so I'm going to need a larger tank anyway.
     

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