I wasn't sure where to put this among all the messages so I started again.

I want to thank those who sent useful information. Thanks particularly to John Corso for the short history of the aluminum tank and Tom C for the link to the Federal Register that contains the new Federal regulations from August 2006. Ah, The Federal Register, my favorite bedtime reading. Those rulings makes it clear that hydro and eddy current testing is only required every 5 years according to the US government regulations. I have been in contact with Luxfer and their policy is that the tanks 6531 tanks require a yearly visual inspection and an eddy current testing (ECT) every 2.5 years as well. Their policy can be accessed at http://www.luxfercylinders.com/support/faq/sustainedloadcracking.shtml#q11

The Federal Register also is clear that there is no new form of ECT required so the equipment that did the EC testing previously is still functional and most large hydro facilities likely already have it. However, I understand there is a better (and expensive) piece of equipment for doing this if one is so inclined to buy it. Thus while there is no “requirement for a new machine” for testing these tanks to meet the DOT regulations, it is a potential expense.

It was interesting to read all the information re: dive stores NOT really benefiting from, it seems the largest beneficiary is Luxfer itself although they certainly aren’t pushing the agenda.
See http://www.luxfercylinders.com/support/bulletins/20060809.shtml

Fortunately I can get my tanks tested properly and then filled through the local dive store we frequent. As a result of all of this however, I have carefully gone through all our tanks and in addition to a number of steel 72s from “the dinosaur days”, we have about 6 Aluminum 80s that were either made by Catalina or of Luxfer 6061 so we can get those filled anywhere.

I also didn’t know or even think about getting40c/lb for the aluminum. I was planning on making a very large set of wind chimes that I still might do rather than lug the tanks around to recycling. It will go nicely with the Anchor Wall we have constructed from anchors we have recovered over the years.

Finally, having dealt with compressors, I’m more than willing even if I had to buy a pallet of tanks and have someone else fill them for us rather than go the compressor route. There is no compressor in the future of the Moby Kate, a 25’ Farallon.