drippy gas tank x2

[HeadSmess]

once its had fuel in it... using a flame is a bit of a nono unless you wash it, wash it, and stick a hose on someones exhaust pipe and into the tank whilst working (exhaust gas doesnt burn) but the process is the same...

get a big fat soldering iron, the old school plumbing ones you heat up in the fire are best.

some plumbing solder and flux. (zinc chloride is best for steel, though rosin core electrical solder works as well...)

clean paint n muck off the base of studs and tank. acetone is best, have to get all the oil n paint off the studs, down to clean metal. apply flux, liberally.

drop a galvanised/zinc plated washer over the stud.

solder the stud and washer to tank.

the washer isnt necessary but does add some strength to a pretty weak area...

will never leak again.... as long as you can solder. got any friends that are plumbers? silver solder is even better, but read my first line!

something i got into the habit of doing to every new tank as the studs ALWAYS start leaking after a few months.

 

[45u]

Your petrol dose not go under the tank. Try in it.

If the tank is leaking around the mounting stud and you use silicon to try and seal it the silicon will be affected by the gas and dissolve. Have you really read his posts? SILICON WILL NOT WORK TO STOP A
GAS LEAK!

 

[skyash]

You fix the leak then stick the tank on. If you fix the leak and do it up to much it will leak again. With the tank glued on you don't need to do up the bolts to much if at all

 

[45u]

You fix the leak then stick the tank on. If you fix the leak and do it up to much it will leak again. With the tank glued on you don't need to do up the bolts to much if at all

Sorry I misunderstood you. I just lined my tank before I ever used it used the bolts have not problem. I have been lining gas tanks on motorcycles for 45 years. The big pot holes and where I ride I do not thing the tank would stay on with just silicon holding it.

 

[skyash]

You would be surprised. And it really works good. I have hit the ground a few times and it holds on.when you hit something With out it you put the strees on the studs. Like I said now I do my bolts up to hold the cable's under the tank not to hold it well a very little bit so it can't move when glue is drying

 

[HeadSmess]

solder the studs on, braze the studs on...either way, the things dont ever misbehave, even if tightened til something snaps...or strips out.

glue or tank linings dont fix the cause, the inherent fault. epoxy is not petrol proof. glue can let go when least expected. tank linings simply pull away from the metal where it gets deformed.

nothing beats fixing the problem itself.

 

[skyash]

Far as I know thay line ocean going craft petrol tanks with epoxy and when I ring up the company thay say that's right but will not guarantee my use of it. Did you say you can use electronic solder? I didn't think it would stick or be very strong. If so I believe you just I never thought of it. Sounds like Good idea

 

[HeadSmess]

yep, plain old electrical solder works, but you need it to be a lot cleaner than if using acid based plumbing type flux. if you have a bottle of pool acid (hydrochloric/muriatic) a quick wipe with it helps etch the steel up. plumbing flux IS hydrochloric acid, neutralized with zinc. a galvanised washer is a source of zinc...

usual soldering rule applies...get it hot (big iron!) and make sure its tinned up properly!

its surprisingly strong, remember they used to solder virtually everything together in the old days... the washer just helps spread the load if you choose to use one.

silver solder is better but you need an oxy torch...once again... petrol tanks and flames are not a good mix.


i should amend that to "not all epoxies are fuel proof". some are.

the jb weld is still going to need a really good clean, and its strength is limited to how well it sticks AND the base metal. once it bends a bit more, off comes the epoxy.

 

[skyash]

I was using fibreglass cut out a small square put a hole in the middle put it over the studs to the bottom covering the weld like a washer then resin I will try solder next time. Thanks

 

[Jeremy/Bicycle Engines]

There is product called Seal All that works really well for fuel issues. I have used it many times in the past for automotive fuel tanks that had a hole punched in them. You can find it at almost any hardware store.