Decipher these tank stamps please.

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Nathan Doty

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I picked up a couple old aluminum tanks today to make some wind chimes. But i want to make sure they're unusable before the cutting begins. If they can be possibly used i'll save them and get them hydrod eventually, otherwise out
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comes the saw!
 
.. to make some wind chimes...
Don't just do a simple cut. This diver made an excellent video on the different sounds from different types of cuts.
 
I'm going to play with them a bit, was going to be my first attempt. I figure no matter what the bottom is coming off :) After I get it hanging I can take one of my digital tuners and try to get an actual note out of it.

I've always rented tanks, never paid any attention to the markings so I'm in uncharted territory at the moment.

In regards to the stamps and what I've read: Old luxfor tanks between 72-88 were 6351, which no -one will or should touch.

If Luxfer made a tank for someone else, it could be stamped sp6498, and is still the bad material, could not/should not be used.

So the silver tank's first stamp was in '73, stamped sp6498 and even though it has an ALCAN mark on it, is likely a handy dandy spinal surgery waiting to happen.

The black tank is stamped E6498 and made in '78. I don't see the ALCAN mark on it though. But if I'm reading right, they're both made by luxfer, and during the bad alloy years. What is the difference in the E6498 and the SP6498? And both are marked 3AL, which one article said grandfathers them as not being the bad alloy. So I'm confused :laugh:

Regardless of the who/what they're probably too old to be cert'd and used, but eventually I might start shopping for tanks to use as tanks, so getting a grasp on things would come in handy.
 
Junk tanks
Aluminum does not have the resonance needed for a chime or bell
Steel Great for Chimes

Suggestions
Cut length wise to produce a Bar B Que
Cut top off for a lamp
Cut under stampings
~~~top - display for collector regulators
~~~bottom - Umbrella stand
~~~bottom - non spillage dog dish
For additional ideas see my threads and post of a year ago
~~ Re-purposed condemned SCUBA tanks ~

SDM
 
What is the difference in the E6498 and the SP6498? And both are marked 3AL, which one article said grandfathers them as not being the bad alloy.
No difference. "Exemption" vs "Special Permit." The 6498 is the key. 3AL is irrelevant.
 
Special Permit 6498 (1972-1976, 2006 - present), and Exemption 6498 (1977-2005). To my understanding, the only difference is the terminology in use at the time of manufacture. SP6498 and SP7042 were eventually "converted" to the 3AL permit and no longer required renewal. A hydro tester has to add the 3AL stamp to make that change legal and applicable on the individual cylinder.

While if these were Luxfer from that time period they are certainly 6351 alloy, the original permit stamp has no inherent direct correlation to the specific alloy used, although if that permit belonged to a manufacturer that only ever used one alloy, you then will know.

Permits 6688,6576,6020,890,12695 for aluminum have long since expired, were not renewed, and cannot be used.

And then there are the Special Permits for steel...
 

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