Re: Adding gas tank drain plug

On Sunday, 15 May 2022 at 01:58:42 UTC+10 62-65-mail...@xxxxxxxxxxx wrote:

Seems I recall "brazing with a brass rod" is one method used to "weld" these. But such gas tank work is very much a
specialty. A welder's discussion forum talked about using inert gas etc. and the consensus actually leaned towards
concluding such work is not for amateurs and that even many professional welders decline to work on them. For
example. "My Dad (with 60 years of welding experience) told me [welding a gas tank is]...as close to a bomb as I'll ever
have in my shop."

https://forum.millerwelds.com/forum/welding-discussions/25770-welding-a-gas-tank

Here is a story from the 62-65 archive (2010) from a Rock Auto newsletter:

"A friend of mine visited a car wash after we had just upgraded the
exhaust system on his 1991 Dodge Spirit R/T. The exhaust caught on the
wheel positioning guides for the automated carwash, pushing an exhaust clamp
into the gas tank and puncturing it. In a matter of a few miles he went from a
full tank to barely making it up his driveway before running out of gas.

My friend had just purchased a MIG welding setup, so we decided to fix
the hole by welding it shut. We removed the gas tank, filled it with
water as much as possible using a garden hose, and rinsed it carefully. We
couldn't fill it completely with water due to the positioning of the fuel filler
neck, but figuring we were safe, we settled down on his front lawn to
weld the hole shut.

As soon as he pulled the trigger on the welding torch there was a
sound reminiscent of a fighter jet blasting overhead just over the treetops. I
had been standing, but when the noise stopped, I was laying on my back and
couldn't recall how I'd gotten there. My friend was also flat on his
back, welding torch still in hand, looking stunned. His neighbors came outside
and were all looking around wondering where the thunderous noise had come
from.

Apparently the small space in the tank that was not full of water had
sufficient fumes in it to ignite causing the explosion. The 16 gallon
gas tank had emptied itself completely of water in a fraction of a second,
leaving only steam wafting out the filler neck hole. It had also doubled in
size, expanding like a balloon, but fortunately hadn't blown to pieces. We
avoided any injury beyond the ringing in our ears and wounded pride.

Needless to say he bought a new gas tank and we never attempted to
weld a gas tank again."

Thanks,
Gary H.

> -------Original Message-------

> don't they do some trick like forcing an inert gas into a tank to push
> oxygen out while welding? i thought I remembered seeing that
> somewhere.
> neal
...