Gas Tank Rust

Discussion in 'Norton Commando Classic Motorcycles' started by 0u812, Nov 13, 2017.

  1. 0u812

    0u812

    Joined:
    Jun 13, 2005
    Peeking in my steel MK3 original roadster tank, I see smallish patches of rust. Nothing too significant, and I realize this is normal but someday I would imagine it will rust through..... maybe not in my lifetime. Is there a treatment to coat the metal or is the general consensus to leave it alone? Years ago, circa 1978, I had a fiberglass tank and I would use a coating to seal. is there a modern day chemical to address this matter or is current wisdom to leave well enough alone? Simply fishing to see what others have done.
     
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  2. toppy

    toppy

    Joined:
    Dec 2, 2012
    I did mine with phosphoric acid an in four years of use and over winter storage with what they tell us is petrol these days it is still grey inside with on traces of rust. Its far cheaper than the various sealing treatments an none of the horror stories of it dissolving or hurting paintwork. My friends have used it to so if your steel tank is not leaking its my recommendation an if your tank does leak get it properly repaired don't trust wonder products that are to good to be true.
     
  3. Danno

    Danno

    Joined:
    Feb 7, 2010
    I used the Bill Hirsch Motorcycle Gas Tank Repair Kit recommended by another member here on the Titanic's leaky steel tank. It comes with 3 components; a cleaner, a rust neutralizer and a sealer. First test had it holding 2 1/2 gallons of premix I had laying around. Next will be a fill-to-the-neck test.

    There are various rust neutralizers/converters out there. Any auto parts store should have some.
     
    OldBalz likes this.
  4. batrider

    batrider

    Joined:
    Aug 9, 2008
    I'm with toppy. First try removing the rust with the phosphoric cleaner and see if the tank leaks. An electrician's fishing chain (for pulling wires up inside walls) works well to knock off any rust inside the tank without being heavy enough to ding the tank. I would avoid any sealers if you can.
     
  5. jaydee75

    jaydee75

    Joined:
    Jul 2, 2012
    I used Evaporust on my rusty Yamaha tank and it cleaned it very well leaving clean metal behind. Not a strong acid and doesn't take any metal off, just the rust.
    Then I'd just keep Stabil 360 in every tankful to resist more rust. I'd definitely avoid any kind of coating on a tank as good as yours.
    Just my opinion.
    Jaydee
     
    jimbo likes this.
  6. texasSlick

    texasSlick VIP MEMBER

    Joined:
    Jan 2, 2013
    I agree with all above who say avoid sealers and coatings.

    Phosphoric acid (many brands available) will remove rust. Here is a link to one such product that goes one step further, and provides a rust resistant surface treatment to protect against future rust.

    https://www.northernsafety.com/Product/87910/Chemprime-1-Gal-Rust-Converter-and-Inhibitor

    Allow the metal surface to air dry. That is when the anti rust inhibitor forms (per personnal communication with Chemprime president).

    Slick
     
  7. geoff1971

    geoff1971

    Joined:
    Jun 13, 2017
    The phosphoric acid leaves behind a beneficial corrosion layer after its drained out and dried. My Norton tank was pretty far gone so I used the caswell epoxy kit to seal it. No issues in 5 years. My Puch had a bad rust problem that I treated with the phosphoric acid method that had a bad case of powdery rust cancer, with nothing else. 4 years on its as clean as it was the day I did it.
     
  8. GavinJuice

    GavinJuice

    Joined:
    Jul 24, 2007
    I currently have mine soaking in vinegar... dissolves the rust and then I plan to hit it with fogging oil when I dump it out.
     
  9. jimbo

    jimbo VIP MEMBER

    Joined:
    Sep 24, 2004
    is this the stuff? Is one gallon enough for a Roadster tank?

    https://www.ebay.com/itm/EvapoRust-...662953&hash=item3d4baf635c:g:JUoAAOSwafBZ4ieW
     
  10. pantah_good

    pantah_good VIP MEMBER

    Joined:
    Jul 17, 2015
    FWIW - and there's plenty of opinions on this subject, we are planning on using Red-Kote fuel tank liner in the new Emgo steel Roadster fuel tank I got when we get to painting it. We previously used that stuff successfully in my R90S steel tank.
    http://damonq.com/Red-Kote.html
     
  11. Danno

    Danno

    Joined:
    Feb 7, 2010
    A gallon should be enough. It's a process of sloshing it around for a period of time, emptying the stuff back into the jug and repeating. It can be used over and over until it's gone. If you have lots of flakes, you can strain it as you pour it back. I bought a gallon to do a cast-iron car manifold and I still have about a quart left from reusing it on other small projects.
     
  12. jaydee75

    jaydee75

    Joined:
    Jul 2, 2012
    Yeah, Jimbo that's the stuff. If you are in the US, you can get it at AutoZone, Advance Auto, Lowes, etc for low $20s.
    Danno is right, slosh around, preferably with a coarse media. Then let it soak overnight. Repeat next day and let soak in a different position, repeat until all surfaces have soaked overnight. A lot of work, but not much alternative.
    Jaydee
     
  13. Danno

    Danno

    Joined:
    Feb 7, 2010
    I used BBs for that__thing. The tank didn't leak, but had interior rust.
    <------------------------I
     
  14. jimbo

    jimbo VIP MEMBER

    Joined:
    Sep 24, 2004
    did you get the floodie bikes tank sealed up?
     
  15. Danno

    Danno

    Joined:
    Feb 7, 2010
    It held 2 1/2 gallons of premix with no leakage. Next I will test by filling it to the neck with regular and letting it sit for a bit. So far so good.
     
  16. Mr. Rick

    Mr. Rick VIP MEMBER

    Joined:
    Feb 6, 2009
    "I used BBs for that__thing. The tank didn't leak, but had interior rust. '

    Yes, I heard about the BB treatment, and did the same thing for some interior rust. It was not that effective, wore my arms out shaking the bloody thing, all the time wondering if I was gonna drop the tank and wreck it. Finally couldn't do it anymore, quit, and discovered the BB's would not come out. They wd fall into the "valley" around the filler neck. Not wanting to remove the petcocks (and not sure they'd come out that way, either) I had to try and flip them out.
    Picture an idiot jerking his tank up, then quickly sideways, and down again in an effort to get them to "jump" out the filler neck, that was me.
    There might still be a few in there, for all I know... :mad:
     
  17. jimbo

    jimbo VIP MEMBER

    Joined:
    Sep 24, 2004
    yep:cool: been there done that, magnets?
     
  18. Danno

    Danno

    Joined:
    Feb 7, 2010
    The last couple BBs were a biotch.
     
  19. Fast Eddie

    Fast Eddie VIP MEMBER

    Joined:
    Oct 4, 2013
    LOL, I pictured it! It seems like the kinda thing I’d do, with the kids watching me in a state of bemusement and mild concern, and the Missus just rolling her eyes and shaking her head...!
     
  20. Brithit

    Brithit

    Joined:
    Feb 22, 2005
    I use drywall screws. They are scratchy. I started out using acid many years ago, then switched over to Evaporust. The lasts tank I did, I used 2 gallons of cheap white vinegar from Sam's Club, and it worked very well. Flushed down the drain when done. Spillage with that doesn't make much of a mess. Takes more time, however.
     

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