How do you keep them from rusting inside? I bought 2 new ones about 30 years ago and threw them out about 25 years ago because the interiors were so rusty. Since then I bought one at a yard sale for a couple of bucks which looked OK at first glance, until I got it home and shined a flashlight inside.I have four - WWll style - steel - Jerry cans. They could easily take a 2 1/2" nozzle. So glad I brought them with us when we moved down from Alaska.