20 year shelf life for Aluminum dive cylinders

[beaverdivers]

I have some steels approaching 50 and others that just hit or are about to hit 40.

How many times have you had them tumbled?

---------- Post added April 7th, 2012 at 09:35 PM ----------

From Science Behind Avalanche 'Air Bag' Saves Skier : NPR

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It takes me about 1/2 an hour to fill and educate, so $20 is cheap.

Jim, would you like a lesson?

 

[Gilldiver]

How many times have you had them tumbled?

The mis-education and confusion about the need or requirements for tumbling are almost as bad as for aluminum tanks. Since starting to dive in 1976 I have never had to have a tank tumbled and that includes using Nitrox/mix since 1993. A tank whip is cheaper, takes less time, is easier, and will do 99.9% of the tanks I see being tumbled for corrosion. As for O2 cleaning, hot soap solution, a large bottle brush, and good rinsing will do it a lot better and faster than tumbling ever will.

 

[Superlyte27]

I am one of those dive shops that will not fill a pre-1990 tank. Not because I'm uneducated, but because I believe I am educated (as evidenced by my PSI Cert).

Here's the issue as I see it. You bring in a tank for VIP/Hydro. We perform the VIP/Hydro/EDDY test and everything checks out just fine. According to my PSI training, just because there isn't a failure point right now, doesn't mean that the issue won't/can't develop 3 weeks or 3 months from now. So, you passed EDDY, but the issue starts developing prior to reaching your next VIP.

A good friend had a fatality in his shop due to one of these tanks. We are a little gun shy. Our blanket policy gives us piece of mind. I promise, we'd rather be alive than collect $4 bucks.

 

[redacted]

Here's the issue as I see it. YoI am one of those dive shops that will not fill a pre-1990 tank....

You bring in a tank for VIP/Hydro. We perform the VIP/Hydro/EDDY test and everything checks out just fine. According to my PSI training, just because there isn't a failure point right now, doesn't mean that the issue won't/can't develop 3 weeks or 3 months from now. So, you passed EDDY, but the issue starts developing prior to reaching your next VIP.

How does that differ from a 5 Y/O tank or even a brand new tank?

 

[bluejaykaren]

I was mad at the time the shop wouldn't fill mine. Not because they didn't want to fill it but because they told me they were worthless and that "nobody" would fill them so I should ditch them.
If they had said "nobody should fill them" I wouldn't have had an issue. That may very well be so but I get them filled all the time so what they told me was untruthfull. Nothing wrong with being safe but a lot wrong with misleading. I was wondering if by ditching did they mean I should have left the tanks there for them.

 

[Superlyte27]

Bluejay,

In my area, no one will fill them, i'm guessing in Florida, the number of dive shops that will fill them is far outweighed by the number of shops that won't fill them. As far as "ditch them", please don't leave them at my shop, lol. They bring about $7 at the recycler, which isn't even enough to cover the gas to drive over there.

awap, the nature of the alloy is how this issue differs from other tanks.

 

[redacted]

Bluejay,

In my area, no one will fill them, i'm guessing in Florida, the number of dive shops that will fill them is far outweighed by the number of shops that won't fill them. As far as "ditch them", please don't leave them at my shop, lol. They bring about $7 at the recycler, which isn't even enough to cover the gas to drive over there.

awap, the nature of the alloy is how this issue differs from other tanks.

It is the alloy and not the age. Age is just a somewhat useful screen. There appear to be some shops like BD that include all tanks in their 20 Y/O phobia. I am somewhat sympathetic with the 6351 issue but do not understand why DOT would allow dangerously defective tanks to remain in service - it must be the data. What about older steel and Catalina brand tanks. Even with the 6351 phobia, I assume a good shop would have no problem with either of those readily identifiable safe tanks.

 

[bluejaykaren]

I surely wouldn't want anyone to get injured filling them on my account. I did ask a shop once what they do with unusable tanks. He said he takes the valves off and sells them on ebay and scraps the tank. I didn't ask him how much he gets and that was several year ago and he may have not been talking about tanks that old. It just bugged me that they said nobody would fill them when I get them filled all the time. They knew I had just dove with them at the bridge. I was wondering how they thought I had gotten that air into them.

 

[Jim Lapenta]

How many times have you had them tumbled?

---------- Post added April 7th, 2012 at 09:35 PM ----------

It takes me about 1/2 an hour to fill and educate, so $20 is cheap.

Jim, would you like a lesson?

If you include educating in use as well then yes that is reasonable. After that though I would not charge to refill a cylinder. And no, I gave up skiiing years ago.

As for tumbling I have only had one tank that needed tumbling. Got it used and it was a newer one. After hydros is the only time they have ever had flash rust issues and a whip took care of them. I only get fills from shops that do partial pressure and have very good air quality.

Tanks do not need tumbled as often as some would have you believe.

Get good dry air and don't let them run dry. My aluminum tanks (5 80's and smaller bottles) have never needed tumbling. A good hydro facility sees to that and O2 cleaning is not rocket science. My tanks that are used for nitrox or mix are only serviced by a shop that does actual tech diving and training. At least until I get a few more classes done to pay for my own set up to clean and dry them in my basement.

 

[DandyDon]

If you include educating in use as well then yes that is reasonable. After that though I would not charge to refill a cylinder. And no, I gave up skiiing years ago.

I doubt he gets repeat customers any year. They wear it, hope to never need it, and if they ever do ride out of an avalanche with one, I have to wonder how many go right back out.