Draining fuel tank to weld frame

[Owenator]

Hey guys,

So I have a crack in my frame, I've found a guy that can weld it but how do you drain it and make it safe to weld? I'd really appreciate info from those that have done it before. I've been told to drain it, leave it in the sun and give it a blast with compressed air but is this really enough?

Thanks for any input

 

[Cooter]

Unless the welding guys shop has a bunch of aerospace things laying around. I wouldn't.

Frames without cracks are available and cheap. In most places your title will have to be modified, but well worth the security vs. an un-known welder.

 

[34nineteen]

Typically the aluminum is heat treated. Once it is welded, it often messes up the heat treat and will crack again around the new weld.

 

[Owenator]

Thanks for all the input. I'm in Hong Kong so getting a frame here is going to be costly. For anyone that's replaced their frame, how much of a pain was it and can it be done without a hoist? I doubt very much I'll be able to find someone to do it for me here, so I'd be doing it myself. I'd say I'm reasonably competent, just finishing putting the engine back in my Bandit 1200 after changing the selector forks...

Thanks again for any input and advice

 

[BuellyBagger]

Replacing the frame should just be a few steps past an engine rotate. Maybe that's an oversimplification, but from what I can tell, if you can manage a rotate... you could figure out the entire frame replacement.

I read through the welding thread that was posted and completely agree with the general consensus that it really shouldn't be done to any major part of the main frame section. I'm not a welder by trade but have many welding certificates and experience with automotive aluminum and steel. I wouldn't weld it.

 

[Cooter]

How did it crack? A wreck? Any other damage?

 

[optomist]

Owenator,

We always charged "hazard pay" to weld leaking tanks. Our practice was to drain the tanks, then run car exhaust(inert gas) into the tanks for 1/2 hour or so and weld away. Yes diesel tanks will blow up as well as gas.

Back in the day I recall guys welding the bottoms of big gas tanks ( dump trucks -- yes there were once a lot of gas powered ones-- Their "technique" was to fill the tanks totally full ( no vapors ) and the fuel would only boil. I remember seeing dripping flames until the cracks were welded up!

Just consult your OSHA manual for further explanation!

3419 is right about the heat treating--know anyone with a large oven--pizza oven should do.

Opto

 

[njloco]

Could you post up a picture of the crack ?

 

[Owenator]

Not sure, just noticed it. It's not on the major welds. On the top of the frame where the tank and seat meet. Not been in any accidents that I know of, which covers the last 4 years or so.

 

[Owenator]

Thanks for your info, I've found a guy that says welding is an option as it not on a main weld, etc but still weighing up my options. I'm away on holiday for the next 7 weeks (tough life, I know) so hence the slow replies, but will try to post some pics soon.