motorcycle gas tank welding -advice needed

Worst I've seen was 50V - telephone exchange busbars. They'd deliver a squiggaamp and not break a sweat. At least 230V usually has some sort of fuse somewhere.

Lately I've been zapping myself with 12V - the electrolytic derust tank, because I'm still to stupid to always switch it off before going near it. It's "only 12V", but across two hands that are wet with salty water, you sure feel it.

Yeah. And it was 400 cycle too.

Garrett

I just got bit pretty good week before last - 277V from the base of my left index finger to one of my forearms laying on the rim of the steel access hatch in grounded steel lath ceiling falsework... Wa-Ha-Ha-Hoooiee!!! Was repeating George Carlin's "Seven Dirty Words" routine for 30 seconds ;-) and shaking my arm for a half hour...

Compared to that, 120V is nothing but a strong tickle. The little (1/8" x 3/8") 2nd degree burn where the wire touched at the edge of my palm (almost on my thumb web) made a dry blister and is healing up nicely.

G--D---ed retail store in an old office building, with the 277V panel for those lights locked up in another office's utility closet. Which made it far easier to pull the wirenut in the ceiling to kill the fixtures we were replacing two at a time...

Moral: Copper wire makes a decent spring and can jump sideways to bite you when you take the wirenut off.

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Now for my method! First, find an old hair dryer, the type that had a hose on it. Discard the plastic head cover. Now, fill the tank with water, and empty. Do this three times. Now, insert the hair dryer hose into the filler hole. Turn on the dryer. The hose is usually smaller then the filler hole, so air can escape. let it completely dry the inside of the tank. Weld immediately. If allowed to sit for a while, the adsorbed fuel molecules on the inside surfaces may slowly evaporate. This can form a combustible mixture.

Steve R.

If you put the exhaust from any engine into it and weld with the engine running you will be ok. The exhaust will not burn, no oxygen. It will stop the fumes from exploding the same way dry ice does. - no oxygen. This works great, and no need to find a supply of dry ice.

Reminds me of the old joke. A parachutist jumped out of the plane, counted 5 and pulled his rip cord. Very little happened. Oh *** he thought. Never mind, dump that canopy and deploy the reserve. Pulled the second rip cord and nothing happened. He is now plummeting earthwards at a fair rate when he sees his pal flying upwards at a similar rate. "Know anything about parachutes?" he shouts. "No" came the reply, "can you weld gas tanks?" Apologies to all who have heard this before.

John

Been there! Also bear in mind that, if you've got one or two good sized grazes on your hands, the current with 12V and the electrolyte can come very close to fatal levels. I have ended up even applying the old BTH test house rules to this situation... "When working on open switchgear, the worker must keep one hand in his pocket at all times". It's a good rule and it usually works.

Mark Rand RTFM

where my boy was working for an off road shop they used and I watched the technique several times they would run the exhaust in the gas tank and go off and do other things and come back in about an hour and weld it up. they would custom fit and modify aluminum gas tanks...

I tried the one listed below I wanted to put an air bleed cap on a 5 gallon metal can washed and washed and then put flame near it and it gave out a big bank and then welde up fine not that I recommend this proceedure. Ed