Damaged gas tank has slow leak... repair options?

Discussion in '2-Stroke Engines' started by Molotov256, Aug 11, 2009.

  1. Molotov256

    Molotov256 Member

    I damaged a gas tank when I took a spill on the bike, and now it's got a slow leak. It appears to be leaking from the base of one of the mounting posts- the post is a little bent, and it's created a crease where the post joins the tank. I can't see with the naked eye if there's a fracture in the metal there, but evidence suggests that's the case.

    I figured I'd just buy a new one until I saw how much they're going for and how much it costs to ship 'em, so now I'm curious about repair options. I know a guy who welds, so I could ask him about that, but welding and gas tanks just don't sound like a good combination. Are there any other viable options? Epoxy? Silicon? Duct tape?

  2. graucho

    graucho Active Member

    I just saw a product at ace hardware. Im sorry I cant remember the name of it but it was a 2-part putty that came in a single tube. The hardener was in the center, cut off a chunk and work the 2 parts by kneeding it together like putty.

    I do know it said it withstands gas. Dries hard as a rock. In the glue-apoxy section.

    Update..... 1 HR later. I was reading "reclaimer's" post http://www.motoredbikes.com/showpost.php?p=219225&postcount=12 and I saw the what looked like the material I saw at the hardware store. I included one of his photos.

    Attached Files:

    Last edited: Aug 11, 2009
  3. machiasmort

    machiasmort Active Member

    JB weld should work!
  4. graucho

    graucho Active Member

    O' sure, come up with a product in 4 words.:grin5:LOL
    Last edited: Aug 12, 2009
  5. Mountainman

    Mountainman Active Member

    just a wild bet from a guy who has been using JB weld for ?? over 40 years ??
    I think that gas eats it up
    well let me go grab a tube -- always have some in and out of the house

    tube of JB KWIK don't say anything about use with gas ??

    graucho has the right stuff listed

    as we ride those things
  6. 5-7HEAVEN

    5-7HEAVEN Guest

    MM, I hope gas does not eat up JB WELD. The label says it repairs fuel tanks.

    I used the epoxy and a large plastic patch to seal the fuel grommet hole in my plastic goped tank. Then I moved the fuel lines to the top of the tank.

    So far it's holding...knock on wood.:whistling:

    Last edited by a moderator: Aug 12, 2009
  7. GearNut

    GearNut Active Member

    I don't know about regular JB Weld, but I once tried to help a friend use JB Quick to fix the carburetor fuel inlet on his Pinto (side of the road repair) and we quickly learned that gasoline ruins it. I was told that if we dried up all the gas before using it and let it cure for a day or two before re-connecting the gas line then it would work fine. I never got to find out though.
  8. 5-7HEAVEN

    5-7HEAVEN Guest

    Methinks it's all about prepping the site. First I used hot glue and a quarter(coin) to patch the brand-new goped tank. HOWEVER, I did not clean or sand the edges and the patch failed.:detective:

    After I peeled the patch off, I had the hardest time peeling the hot glue off the quarter!

    With the JB WELD I followed the directions, especially the prepping and curing time.

    It worked very well.
    Last edited by a moderator: Aug 12, 2009
  9. Molotov256

    Molotov256 Member

    I grabbed a tube of the stuff Graucho mentioned from an auto part store, and it was labeled as an "instant gas tank repair", so it better hold up in the presence of gas!

    I put a patch of the stuff around the base of each of the 4 posts, so we'll see if it holds up.
  10. Just_Gasit

    Just_Gasit Member

    Brazing works well. Empty tank (well, of course) flush, flush again and braze with the cap and valve off. I did a Honda trail 50 tank that had pin hole rust all over the bottom. I pretty much brass plated the whole tank bottom. Had the bike for ten more years and it never leaked again. The poduct Kreem works well I hear but it's expensive and was more than I wanted to spend for the little Honda. I think a new tank would cost much less than Kreem for a HT engine kit.
  11. andynogo

    andynogo New Member

    I usually solder tanks up. Much less heat than brazing (which does work well) so might be easier for some.

    Clean the tank out with degreaser then soapy water, blow it out till there's no trace of petrol in it.

    Clean the paint off around the entire area to be fixed plus a bit, heat up with a small blowtorch or a really good powerful soldering iron, use baker's fluid or similar steel flux and tin it up with ordinary solder. Works a treat.
  12. machiasmort

    machiasmort Active Member

    Not bad advice Andy. I'd stick w/ a propane torch though! Unless you can get directly behind the hole with the iron.
  13. w31john

    w31john Member

    I cut them off and weld on the next bigger size allen bolt
  14. radrob

    radrob Member

    i called jbweld . they said the original is the best if its dry and you have the time. but jbstick will dry with the presence of gas.
    i have had 2 of my first 3 tanks leak.
  15. Al.Fisherman

    Al.Fisherman Active Member

    That is what I'd do and that is braze it (do it right). Don't flush with water..here is a sure way to neutralize the gas and fumes. First empty any fuel in the tank, tip and use a rag. Attach a hose to a exhaust pipe (I use my Miata) and force as much exhaust into the gas tank you can. Do this till the tank gets good and warm...braze away. If you think this is BS try this sometime, take a container like a tank, leave a little gas in the tank. Flush with exhaust till tank is good and warm. If any fuel remains pour on the ground and try to ignite it...can't be done. When ready to braze, pass the torch by the inlet...you might get a LITTLE poof (less then a real good f**t), and that's it.
    Someone mentioned solder...that is good also.
    Last edited: Aug 23, 2009
  16. radrob

    radrob Member

    true thats how the brazed my tank in me volkswagen scirocco. fired up a lawnmower engine hooked up a hose from the exhaust and brazed away!!!
  17. dirbob

    dirbob New Member

    gas tank repair

    In the old days we used a chemical called Triclorethane to kill the gas fumes in a gas tank. If you can find Triclor just put it in a sprayer and spray the in side of your tank. It will kill the gas fumes and you can weld on it all day. We used to kill a 10,000 gal gas tank with about a gallon of it, and then would cut it in half with a cutting torch. Hope this gives you another option. Bob
  18. Just had the same thing happen to me more or less. After searching the internet and brainstorming this is what I came up with. Prep area and use jb water weld around mounting posts where leaking, and use a washer over top that will cover cracked area, push washer into jb waterweld And let it fully cure. Then cover washer with jb waterweld and let that fully cure, ill let you guys know how it holds out as it should work better then the common technique of just using jb waterweld.