sealing up metal water tanks

[aj]

I have probably 10 metal water tanks I am always hauling around. Seems like they develop leaks. I bought a bucket of bentonite. When I seal a tank up I have thrown in a couple buckets of badger dirt (clay) and then also a small amount of the bentonite that seems to help. Any body do it different?

 

[beebe]

Depending on where the leak is Black Jack might work.

 

[Doc]

As I've seen the rust spots start on the outside I've used that silver fibered roof covering that is like a thick paint with pretty good results. What about that stuff you see advertised on TV that they build the air boat out of?? I know they sell the tape and the paint version in Home Depot around here.
That's why I've changed all my tanks over to the hard plastic ones.