Glass air tank???????

just get one the same size as a hydraulic tank and use the hydro pump caps with longer rods to tighten both ends towards each other. then just tap and thread the caps off the hydro pumps and install fittings.

well it wouldn't be too hard to keep clean. most of the dirt and nasty stuff inside an air tank comes from the tank itself rusting on the inside. as long as you have a good water trap and some way to drain the water from the tank, it shouldn't be too bad to keep clean. still the hardest part would be keeping the moisture from condensing inside the tank and hazing up like headlights and corner lights do when they get moisture in them