Buying air tanks

[Terry]

  Aluminum cylinders with an original Hydro date before 1980 will require an Eddy current test at Hydro time due to neck cracking issues, adding to the bill. I had a LDS "condemn" one of my Al 80s due to "pitting" so I bored 4" diameter holes in it and made a planter out of it, it was at that time I could easily see the "pitting" was nothing more then the standard flakey white dust of Aluminum oxide that you can see on a substantial number of Al cylinders with more then several hydros on them, with no measurable depth to the "pitting" at all. I own a total of 17 cylinders about half and half (Al vs steel) overall I'm happier with the steels, for a few reasons, I like that their more negitively bouyant, the galvanized coat on steel cylinders although not as pretty as paint is MUCH more durable, and I like the fact that steel scuba cylinders with a 3AA stamping (actually made of Chrome Molylidnieum steel) (3A cylinders are made of carbon steel in use as welding tanks (and other purposes)), are structurally so much stronger then Aluminum. By Luxfer's own admittion their brand new Al 80s if pumped to rupture, will start to blow at 6200psi (thats only 1200 psi above hydro pressure,) where PressedSteel states their cylinders will go 12K-15000psi before rupture. Not that any of this really matters,,, if I was 185' down and found myself out of air, steel vs AL,,,, if the tank has air in it, I wont be as choosey      :-\    Terry