How old is too old when it comes to AL tanks

[dmccarver1]

What is the expected life of an aluminum tank? I mean this in terms of using it to dive with. I was given two AL 80's when I first started to dive, they were made in '83. But have passed hydro/vis every time, and have just recently passed hydro/vis. I took a class this past weekend and the Owner told me that he would fill them this time since I was taking a class but not after and I needed to get new tanks. He said that they were within the year of the tanks that are exploding. Isn't that the purpose of having them hydro'd and vis inspected, and isn't it just as likely for a new tank to have a defect as the old ones?
I've been needing an excuse to get a steel tank, but would like to keep my AL tanks. Any thoughts on this matter.

[divinginn]

I had one of those tanks with a cracked neck,with a recent hydro and vis,scared the crap out of me when the guy filling it showed it to me.He took it upon himself to check it before filling it,glad he did,it probably would have blown,I now have all steel tanks,two of them over 40 years old without any problems.

[TxHockeyGuy]

If they are older 6351 aluminum tanks (yours probably are). Get rid of them.

Refused To Fill Tanks

Tank Explosion 6351

[ReefHound]

Technically, they are too old when they no longer pass visual and hydro. Practically, anything before 1990 is going to be more trouble than it is worth. The alloy used before 1988 (most shops just use 1990 as an easy to remember cutoff date) had a tendency to suffer sustained load cracks. The current alloy is much better so the answer is no, the newer tanks are not as likely to suffer defects.

More and more shops, including Scubatoys, will not fill pre-1990 tanks. You'll be fighting a losing battle and as Larry explained here it just isn't worth the risk considering how much value you'll get from a new tank in the long run. Perhaps my perspective is skewed because I sometimes fill tanks for my shop since the most likely time for a catastrophic failure is during the filling.

[ReefHound]

As one of those links pointed out, the Catalina tanks did not use the problematic alloy but you'll still run into the "no fill pre-1990" blanket policy at dive shops.

[CompuDude]

Originally Posted by ReefHound

As one of those links pointed out, the Catalina tanks did not use the problematic alloy but you'll still run into the "no fill pre-1990" blanket policy at dive shops.

Those dive shops are wrong, and clearly uneducated on the subject. But that's small comfort when you want to dive and the idiot behind the counter is pointing to a sign and saying "sorry, buddy".

[mike_s]

I agree that a lot of these dive shops are wrong and uneducated. but some also seem to impose the 1990 rule as a general date because they don't want to check certain tanks to see when the "cut off date was".


However, I used to think there was nothing wrong with the older tanks if inspected properly.

I "retired" the pre 1988 tanks I was using long ago though.

But I've changed my mind after I've seen one crack first hand right after it passed hydro. While I'm sure there are some older 6351T6 tanks out there that are ok, I choose not to have to hassle with them. a lot of shops won't fill them, especially in my area.... so they are worthless here.


I even got some guy on Craiglist ticked off when I told him that I wouldn't buy the tanks he had that were "brand new" and only used once since purchase in 1985. I told him non of the local dive shops would even fill them. What does he do? he calls up the LDS and complains to them. go figure.

[in_cavediver]

I don't personally agree with the 'pre 1990' ban. I wholeheartly agree with and understand the 'No T6351' ban though.

Its a pity some perfectly good catalina tanks are being shunned.