[jcs64]

So I just put my tanks back on my'72 FL after adding a pogo seat setup.

I always had a "wet" mark around the mounting stud (the one that mounts to the same bracket as the Seat "T" bar). If I sniffed the crack, scratch that, I mean if I smelled between the split tanks I could smell gas so I new it had a slight leak.
Well, now its an official leak. Dripping off the stud and running down the backbone. I drained the fuel and left the caps off to air out a little. What should my plan of attack be on it tommorrow?

- Weld around the stock stud?
- drop a large washer around the stud and weld the stud to the washer and the washer to the tank (This will spread the load and cover the crack)?
- Chemical seal the inside?

Im thinking option two is the best bet, what do you guys think?

Jeff

 

[Guest]

POR15 it, it won't leak again. At least mine hasn't in 3 years.

 

[hogster]

you scratched the crack and sniffed it ? you talkin motorcycles or what ? dripping off the stud and running down the backbone ? wet mark around the mounting stud ? smell gas between the splits,for crying out loud roll it over man.the food in that diner tastes like shit...seriously I would get a new tank.why is the leak there did it have too long of a bolt put in ? or just plain vibration.if the leak is from the bottom of the hole you could put dope on the bolt,a new tank may be cheaper than having someone braze it for you.cause the brazing is likely to blister the paint job any how.as far as lining it with something that wont react to todays corn-gas good luck new or good used tanks are not that costly.the repaint is what may cost the most good luck on a safe solution

 

[lilclay81]

You dont need a new tank. Just take the tank off and wire wheel around the stud. Get it nice and clean then get yourself some flux and solder. Then just solder up the holes and presure test the tank. Just keep a wet towel around the area so it won't pop the paint. Or weld it up with a welder and touch it up after your done.

 

[sixball]

Your paint is the problem. Looks like you spent some time or money on it, and it'd suck to ruin it. With the liner, thats just a band-aid on a sucking chest wound. Liners are made more for rust prevention, not sealing up cracks. It will seal up a crack or tiny pin hole, but you never know for how long, then your back in the same boat with a leak.

If you put liner in it, you risk getting it on your paint durring the twisting turning process. Welding is going to introduce alot of heat, and screw the paint up. You need to get some dry ice and rid the tank of any gas/fumes. sand down to the bare metal, weld it up with a friend and some wet towles and ice cubes nearby. Hopefully you can keep the paint damage to a minimum and touch it up.

The JB Weld tank repair stuff and others like it, work if applied right (you have to apply to the bare metal) but again, you never know when it will fail. Especially near a mounting/stressed part, you need a solid repair.

Sixball

 

[dudley32]

I've used Marinetex...on two tanks...one gas one diesel...on the outside of the tank...one has lasted 20 years now...

 

[underrust]

I've had mine soldered repair and then used a stud and rubber washers, seems to have worked. If anything at an angle it will put too much stress at area.

 

[Markee]

I use liners (Por15) in tanks that are modified. But I wouldn't feel very confident about fixing a structural area with a crack.

Had success welding leaks on nicely/new painted surfaces. I remove paint as little as possible and TIG using 1/6 silicon bronze filler rod. The bronze flows and uses less heat.

 

[jcs64]

Ok, off to pull the tanks now. Ill see what im up against in a bit or two.

As far as the paint, Its only about $35 dollars of duplicolor, but id hate to have to redo it. Im sure id be alright w/ the welder since its far enough away from the finished surface so the heat shouldnt get to it..

gotta go, Jeff

 

[jcs64]

is that stud threaded into the tank?

jeff

 

[76tri]

I used a cold spray from bernzomatic, and a tig with silicon bronze rod. Barely a blister around the the repaired area. you should br able to find it at home depot for a lot cheaper...
http://www.amazon.com/gp/aw/d/B004XKDRCG/ref=redir_mdp_mobile/192-9768598-1926462

 

[jcs64]

Pc of cake, If I had more time tonight, I would have been able to get it all back to gether too.
Here you can see that it was leaking from around the stud.

Or was it?
Wrapped up nice and safe, I was able to clean the area too see what I was dealing w/

Nope, It wasnt the stud, the tank actually cracked around the weld.

All welded and checked w/ some air presure and and soapy water. (I also melted some soldier ardound the stud for good measure) After a quick squirt of black, were good to go.

Ill look over the other side good before I button things back up just to make sure this dosent come back for a repeat performance on the other side.

Jeff

 

[Friday]

nice job ..and those studs do come out ,they shouldve made them like the front mounts =large surface area and quicker.

 

[hogster]

my fat-bobs dont have a stud but a boss in the tank ,and a bolt is required.you may be looking at a previous repair that failed.but since you have it fixed already congratulations and hope it holds out for you

 

[Buellbomb]

my fat-bobs dont have a stud but a boss in the tank ,and a bolt is required.you may be looking at a previous repair that failed.but since you have it fixed already congratulations and hope it holds out for you

That's the way my '79 Low Rider was. I repaired both sides during the 79K I put on it.

 

[TDWZ28]

When you re-install the tank, it is very important that the tank lays flush with the mounts. If there is any gap at the front mount, you have to shim it or adjust the tabs on the tank so it fits flush. The rear mount on the frame can also be adjusted to fit better. The reason they crack at the weld is because of a bind. Any binding will stress the tank at that spot. I speak from experience.

 

[Dave Carney]

I agree with TDWZ28. If theres any stress when you tighten it up, it will surely crack again.

 

[sixball]

Nice bead. What kinda welder did you use?

Sixball

 

[jcs64]

thanks guys.
I do have shims in different spots but Ill double check that everything still mounts up flat.
As for the bead, Im just learning TIG w/ a lincoln (I think its a 180SD). Im pretty Sure the bead your talking about is the factory one since I didnt post a close up pic of mine (and theres a reason why, LOL).

Jeff

 

[chopperjunkie73]

thats why all the new stuff is rubber mounted but not cool like the old bikes