Re: anchoring to the celing in a bluebird
depending on the bus, most newer ones have an inside panel, insulation, and the roof panel. i think they are probably 20 gauge thickness or so steel. also in there is the wires for the speakers if equipped, and the wires for the overhead lights. If i were going to put a tank or something inside... next to the roof, i would most likely support it from the floor if i had no welder to build a proper roof structure for support.
Jesus Christ... Conversion in progress.