I need a new compressed air tank, the old one rusted out. I bought a 5 gallon tank at Tractor Supply, had it filled, and when I went to use it a few days later, no air. Returned to store. Looked at Home Depot, they carry compressors but not just a tank. Walmart sells a 7 gallon Briggs & Stratton tank, but I would rather have the smaller, lighter 5 gallon size. Suggestions? Thanks!