The dreaded tank leak
 

1990 cbr 1000f
Been noticing fuel smell after last couple times filling the tank. Its leaking from behind the spot welded metal plate that has the mounting tabs up front, same place as many here have had the same issue.
I've read some of you have sealed the inside of the tank, jb weld, soldered, etc. Has anybody had theirs re-welded? I know its something a pro would need to do, I'm just curious if the metal is too thin, or if it can be done. I'd really like it to be a permanent fix.

Motorcycle tanks are actually pretty thick-walled compared to most automotive sheet metal. I've welded and used studguns on them with no trouble. If you're nervous, try running in with a barbeque lighter before welding. I couldn't even get a puff of flame. Obviously drain and vent it for a couple days, and be sure to leave the filler cap off so it doesn't pressure up. You really don't want that

That said, some welders will be nervous about it. The perception is that it's dangerous. You could always purge the tank with mig gas to be extra extra safe

I'll stand behind this statement. Not an expert or a good welder but along with waiting for the tank to completely become vapor free in a vented state, which it will, there are also chemicals to mitigate and clean out the gasoline along with its vapors. I remember working for a truck stop/fuel delivery company that had a gasoline tanker they needed to weld. I watched them pour water with some kind of chemical in the tank and slosh it around for an hour while I was working around the shop. Wish I knew what they used but it was such a long time ago. And that was an 11,000 gallon tank - I don't think a motorcycle gas jug involves much to make safe.

So if somebody won't weld your tank it's because they don't have the talent. Find somebody else.

Awesome! Thanks guys. Upon reading first reply earlier I commited to taking it to my painter this weekend. He says it should be no problem. He has been welding/fabbing/painting custom chopper/cruiser bikes for years. Being mostly dealing with american cruiser bikes myself I'm used to the thicker walled tanks they seem to have.
I will post a pic or two tommorow or friday and then the finished result. I am out and about tonight but wanted to at least post a quick reply so you know I'm closely following the thread

Dropped off the tank last night. He will be grinding the three welds that hold the mounting tab to the frame, then tig weld with silicon bronze around the entire spot-welded plate, then weld the mounting tab back on. After that I will seal the inside of the tank with red-kote. (Tank is excellent shape and rust free) I'll post pics of progress.
The leak was coming right inbetween the tank metal and metal plate where my finger is at

https://cimg1.ibsrv.net/gimg/cbrforu...bc1a8516e3.jpg

Well I certainly dont expect to have THIS problem again.
all welded up like a work of art! And I think its safe to say its going to be a bit stronger than those spot welds, lol!
next step is to seal the inside of the tank with red-kote just for some good preventive against rust in the future

https://cimg1.ibsrv.net/gimg/cbrforu...98c5fc6c52.jpg

Nice. Those heat bands are envy - you can see how evenly the heat entered the panel. That's a practiced hand alright... Was it a bodyman or an industrial guy? We didn't see TIG used much, but it's definitely the better choice for anything that needs to seal tightly

Camera looks a little crooked, so assuming the test fit was good?

Are you gonna bomb it? I'd recommend knocking that paint edge down a bit before you do, and chasing with a etching primer before topcoat. Doesn't need to be fancy (cough sprayable undercoat cough) but it'll last longer and protect better if you do. Welds are always a rust magnet

That looks like a good permanent repair - Sweeeeet!!

hes pretty experianced in body work and industrial/machine welding type stuff. The fit is great but the mounting tab did move a wee bit on him, thats why it appears a bit crooked. Hes going to fix it and then the whole tank is getting a show-finish repaint since it affected the top side of the finish also