I just obtained a 200 gallon farm tank from my neighbor. Way too big for me but better than nothing. It was used for farm diesel. I would like to use it for gas. What do I need to do to clean it, rinse it, before I put gas into it?
You shouldn't need to clean it out to much. A small amount of Diesel won't contaminate the gas. As cp1969 said I would check to make sure it's not rusty inside. Also, on a gas tank you should install a 10 to 15 foot tall vent tube on the top of the tank. This will prevent gas fumes from accumulating near the ground.