Gas Tank Leak repair what are my options??

Viewing this thread for the first time. I know I'm chiming in a year later, but have had great success using Plug N Dike powder in the Fire Service handling leaking gas tank emergencies in the field. It is a powder, mix it with water till u get a play dough consistency and slap it on the leak, It hardens from the petroleum interaction.
Some of our handiwork is still holding up.
Hope it helps someone.