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    Fixing Rusted Out Gas Tank

    Bought a Skunk tank as a project knowing it would need some paint work and a failing liner removed. Stripping the outside reveled epoxy patches on the bottom and holes though the metal. Been trying to patch them up by brazing but it's really frustrating - every time one hole is filled another shows up. Had to fashion two patches (so far) because as soon as the torch warmed the metal the holes expanded.

    Have to get this thing fluid tight before attempting to strip the liner out and then derust. I'm almost positive that this think is going to spring more leaks as soon as that process begins.

    I've never messed around with solder before but wondering if I should tin the bottom front area where all the leaks are.

    Any words of wisdom?
    Ed

    To measure is to know.

    Mikuni O-ring Kits For Sale...https://www.thegsresources.com/_foru...ts#post1703182

    Top Newbie Mistakes thread...http://www.thegsresources.com/_forum...d.php?t=171846

    Carb rebuild tutorial...https://gsarchive.bwringer.com/mtsac...d_Tutorial.pdf

    KZ750E Rebuild Thread...http://www.thegsresources.com/_forum...0-Resurrection

    #2
    Regular solder is to soft and doesnt take well to expansion and contraction cycles. PM me some pics and I may be able to mig it up for you and then skim it with some JB weld to reassure there are no micro cracks.
    MY BIKES..1977 GS 750 B, 1978 GS 1000 C (X2)
    1978 GS 1000 E, 1979 GS 1000 S, 1973 Yamaha TX 750, 1977 Kawasaki KZ 650B1, 1975 Honda GL1000 Goldwing, 1983 CB 650SC Nighthawk, 1972 Honda CB 350K4, 74 Honda CB550

    NEVER SNEAK UP ON A SLEEPING DOG..NOT EVEN YOUR OWN.


    I would rather trust my bike to a "QUACK" that KNOWS how to fix it rather than a book worm that THINKS HE KNOWS how to fix it.

    Comment


      #3
      See my thread Cooley tank saved for an example of what i started with and what i can do.
      MY BIKES..1977 GS 750 B, 1978 GS 1000 C (X2)
      1978 GS 1000 E, 1979 GS 1000 S, 1973 Yamaha TX 750, 1977 Kawasaki KZ 650B1, 1975 Honda GL1000 Goldwing, 1983 CB 650SC Nighthawk, 1972 Honda CB 350K4, 74 Honda CB550

      NEVER SNEAK UP ON A SLEEPING DOG..NOT EVEN YOUR OWN.


      I would rather trust my bike to a "QUACK" that KNOWS how to fix it rather than a book worm that THINKS HE KNOWS how to fix it.

      Comment


        #4
        Just an idea, but tape it up good on the outside,P.O.R it then use filler on the outside to smooth things out n make it pretty,P.O.R. dries rock hard doesn't it?
        Upon prepping my tank for paint i came across quite a few holes.But it did not leak due to tank lining so i used quicksteel then sanded smooth primed the painted,came out nice n smooth.

        Comment


          #5
          Not sure how bad your leaks/holes are, but a radiator repair shop might be able to help you out. They can do some pretty amazing repairs when they put their mind to it. They can then boil the tank out and pressure test it, too. I've had a friend tig weld some pinholes for me in the past, also. It doesn't take much to zot them closed with the tig method. I've had little success with soldering.
          1979 GS1000S,

          1982 Honda CX500 Turbo, 1982 Honda MB5 w/CR80 motor, 1977 Honda "nekid" Goldwing, 1976 Honda CB550F cafe', 1972 Honda XL250 cafe'

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            #6
            Originally posted by chuck hahn View Post
            Regular solder is to soft and doesnt take well to expansion and contraction cycles. PM me some pics and I may be able to mig it up for you and then skim it with some JB weld to reassure there are no micro cracks.
            Chuck,
            The metal is paper thin in places. I'm afraid welding heat will blow holes though it. And JB Weld won't do me any good since the liner stripping chemicals will eat it.

            Thinking body solder. Eastwood sells it.
            Ed

            To measure is to know.

            Mikuni O-ring Kits For Sale...https://www.thegsresources.com/_foru...ts#post1703182

            Top Newbie Mistakes thread...http://www.thegsresources.com/_forum...d.php?t=171846

            Carb rebuild tutorial...https://gsarchive.bwringer.com/mtsac...d_Tutorial.pdf

            KZ750E Rebuild Thread...http://www.thegsresources.com/_forum...0-Resurrection

            Comment


              #7
              LOOK AT MY THREAD!!!! If i can start with "paper thin" rusted holes .like that then dont be so quick to write it off!! PM Frank and ask him his opinion too if you wish.
              MY BIKES..1977 GS 750 B, 1978 GS 1000 C (X2)
              1978 GS 1000 E, 1979 GS 1000 S, 1973 Yamaha TX 750, 1977 Kawasaki KZ 650B1, 1975 Honda GL1000 Goldwing, 1983 CB 650SC Nighthawk, 1972 Honda CB 350K4, 74 Honda CB550

              NEVER SNEAK UP ON A SLEEPING DOG..NOT EVEN YOUR OWN.


              I would rather trust my bike to a "QUACK" that KNOWS how to fix it rather than a book worm that THINKS HE KNOWS how to fix it.

              Comment


                #8
                Originally posted by chuck hahn View Post
                LOOK AT MY THREAD!!!! If i can start with "paper thin" rusted holes .like that then dont be so quick to write it off!! PM Frank and ask him his opinion too if you wish.
                Chuck,

                Thanks for the offer and all, but I'm not going to ship this tank across the country for someone else to fix. I want to fix it myself.

                Oh, and I have no idea what thread you are referring to.
                Ed

                To measure is to know.

                Mikuni O-ring Kits For Sale...https://www.thegsresources.com/_foru...ts#post1703182

                Top Newbie Mistakes thread...http://www.thegsresources.com/_forum...d.php?t=171846

                Carb rebuild tutorial...https://gsarchive.bwringer.com/mtsac...d_Tutorial.pdf

                KZ750E Rebuild Thread...http://www.thegsresources.com/_forum...0-Resurrection

                Comment


                  #9
                  Saving the paint is obviously not a concern, so I would strip the ares(s) with paint stripper and apply a temp patch of bondo so you can do the acetone or whatever to strip the lining. Then chip the bondo off ans hake any chips out of the tank. Then do as Caswell says in their kits. Duct tape over the areas, apply the liner and let it harden. Once its hardened you can skim coat it with filler and proceed with the repainting as if there was never a hole to begin with.
                  MY BIKES..1977 GS 750 B, 1978 GS 1000 C (X2)
                  1978 GS 1000 E, 1979 GS 1000 S, 1973 Yamaha TX 750, 1977 Kawasaki KZ 650B1, 1975 Honda GL1000 Goldwing, 1983 CB 650SC Nighthawk, 1972 Honda CB 350K4, 74 Honda CB550

                  NEVER SNEAK UP ON A SLEEPING DOG..NOT EVEN YOUR OWN.


                  I would rather trust my bike to a "QUACK" that KNOWS how to fix it rather than a book worm that THINKS HE KNOWS how to fix it.

                  Comment


                    #10
                    Silver solder????

                    Comment


                      #11
                      Here is a video showing a guy soldering a tank...http://www.youtube.com/watch?v=AT8Eb...feature=relmfu

                      Major holes are filled with brass, then solder is flowed over the area to provide a hedge against more leaks.
                      Ed

                      To measure is to know.

                      Mikuni O-ring Kits For Sale...https://www.thegsresources.com/_foru...ts#post1703182

                      Top Newbie Mistakes thread...http://www.thegsresources.com/_forum...d.php?t=171846

                      Carb rebuild tutorial...https://gsarchive.bwringer.com/mtsac...d_Tutorial.pdf

                      KZ750E Rebuild Thread...http://www.thegsresources.com/_forum...0-Resurrection

                      Comment


                        #12
                        The problem is many fold..thin metal and torch is just melting larger, no base metal for solder to sit on ( just will drip thru the holes ) and theres already a liner in there.
                        MY BIKES..1977 GS 750 B, 1978 GS 1000 C (X2)
                        1978 GS 1000 E, 1979 GS 1000 S, 1973 Yamaha TX 750, 1977 Kawasaki KZ 650B1, 1975 Honda GL1000 Goldwing, 1983 CB 650SC Nighthawk, 1972 Honda CB 350K4, 74 Honda CB550

                        NEVER SNEAK UP ON A SLEEPING DOG..NOT EVEN YOUR OWN.


                        I would rather trust my bike to a "QUACK" that KNOWS how to fix it rather than a book worm that THINKS HE KNOWS how to fix it.

                        Comment


                          #13
                          Originally posted by Nessism View Post
                          Chuck,
                          The metal is paper thin in places. I'm afraid welding heat will blow holes though it. And JB Weld won't do me any good since the liner stripping chemicals will eat it.

                          Thinking body solder. Eastwood sells it.
                          I know what you mean by paper thin, I remember Chucks thread and it was a decent repair, I think on the front top of the tank. I had something similar and completely washed a layer of braze over the bottom of the tank where it rusts through and sealed it just fine.
                          What about cutting out the bad metal completely and brazing a patch? I personally don't like welding tanks where the metal might be thin because there's different flex/movement charecteristics that might cause leaks along the weld joint, silver solder or braze. The tank on my 1000s with the nice paint sprang a leak where the front rubber locates, I think the spot welder must'v been turned up a bit too much, that was silver soldered up and has not given problems since.
                          sigpic

                          Don't say can't, as anything is possible with time and effort, but, if you don't have time things get tougher and require more effort.

                          Comment


                            #14
                            I've seen this tank. it's a bit of a mess. It's already fully stripped of paint.

                            Ed - as you know my original skunk tank had a "weep" in the front right hand corner on the seam before I POR15 coated it.

                            I think you'll be fine with flooding the area with brass to seal it. To seal mine to stop the Evaporust, Marine clean etc leaking out I used a layer of epoxy & then just filed it back to nothing before I painted the tank. Not counting on the epoxy for a permanent repair, counting on the POR15. I also brush painted the POR15 sealer on the outside of the tank in the offending area before painting.

                            For anyone suggesting JB weld as a temp fix - forget it, doesn't work. 2 part expoxy ("araldite" for those that know it) works much better.
                            1980 GS1000G - Sold
                            1978 GS1000E - Finished!
                            1980 GS550E - Fixed & given to a friend
                            1983 GS750ES Special - Sold
                            2009 KLR 650 - Sold - gone to TX!
                            1982 GS1100G - Rebuilt and finished. - Sold
                            2009 TE610 - Dual Sporting around dreaming of Dakar..... - FOR SALE!

                            www.parasiticsanalytics.com

                            TWINPOT BRAKE UPGRADE LINKY: http://www.thegsresources.com/_forum...e-on-78-Skunk/

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                              #15
                              Silver solder 'spread as a covering' works well if you have enough of a skin for it to grab hold of. If she's too 'Swiss cheese' for that I would cut the section out and replace.
                              79 GS1000S
                              79 GS1000S (another one)
                              80 GSX750
                              80 GS550
                              80 CB650 cafe racer
                              75 PC50 - the one with OHV and pedals...
                              75 TS100 - being ridden (suicidally) by my father

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