When I worked at Scott's Machine Shop (my Dad's business) back in the day (of the Beatles and Stones), we were often called on to repair leaking vehicle gasoline tanks.

This could be a thrill for you TJ; pay attention!

We would remove the tank from the vehicle and drain (most leaks were on the bottom of the tanks and brazing overhead is tricky).

Then we would fire up the the old 49 International pickup truck with flex tubing running from the exhaust pipe to the filler neck of the gas tank being repaired. We used pink shop rags (you know the ones that the rag truck delivered and picked up the dirty ones to be washed) packed around the flexible tubing to prevent most of the exhaust fumes from escaping to the atmosphere.

After a few minutes the gasoline tank fumes would be rendered harmless(??) by the carbon monoxide in the exhaust fumes. At that point it was safe(??) to braze up the leak or crack. Many times we added a galvanized tin patch to prevent a recurrence of a crack or leak.

We used the cutting torch method to remove drum heads back then too. Sometimes one would poooffff... through one of the bungs when the torch penetrated the drum. It was a safety rule to keep your face away from the open bungs at the initial cut.

Safety always came first back then. The definition of safety was much different than today! We considered brazing on gas tanks, torching drum heads and such to be safe activity.

A little later in life I became a Safety Engineer for an insurance company. I think that may have been penance for all risks taken and survived in the Scott's Machine Shop days.

Life is Good on Bremer Pond!