The present invention is directed, in part, to an apparatus and methods related to an expandable storage tank for compressed gas, the storage tank prepared from a puncture resistant, flexible fabric material in which the storage tank is expandable to a desired volume when inflated and when deflated. During periods of non-use the storage tank is retracted in a compact and folded manner to save space compared to when the tank is inflated. The storage tank is utilized by employing its use in conjunction with a traditional air compressor and can be configured with or without a rigid outer shell that expands in relation to the amount of compressed air transferred into the expandable storage tank.