candudave
Registered
Someone is selling 2 US Diver Aqualung 80 cu ft Professional Aluminum Tanks which have not been hydroed since 1989. Should I be wary of these.
PS They're cheap
PS They're cheap
Used tanks ?
- Thread starter candudave
- Start date
Please register or login
Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.
Benefits of registering include
- Ability to post and comment on topics and discussions.
- A Free photo gallery to share your dive photos with the world.
- You can make this box go away
Yes
While they will probably re-hydro and VIP just fine it is getting increasingly harder to get fills on older aluminum cylinders. I have seen the resistance escalate this summer.
One shop won't touch them. Another will VIP pre 1990 cylinders for $120, obviously he wants them to just go away.
Once you buy them, even cheap do the hydro, VIP and perhaps a valve rebuild they get less attractive. If they fail you are out $$ for sure and as I said getting them filled will be hit or miss.
Pete
While they will probably re-hydro and VIP just fine it is getting increasingly harder to get fills on older aluminum cylinders. I have seen the resistance escalate this summer.
One shop won't touch them. Another will VIP pre 1990 cylinders for $120, obviously he wants them to just go away.
Once you buy them, even cheap do the hydro, VIP and perhaps a valve rebuild they get less attractive. If they fail you are out $$ for sure and as I said getting them filled will be hit or miss.
Pete
jefffalcone
Contributor
Tanks from 1989 should be fine. It's my understanding that the questionable alloy was discontinued in 87 and wasn't used at all after 88.
Correct me if I'm wrong.
Correct me if I'm wrong.
jefffalcone:
You are correct but that does not capture the spectrum of dive shop behaviors. Some are even calling anything over 20 years taboo. Much of this is founded in ignorance and paranoia so don't expect it to make total sense.
As I said the tanks probably are fine, even those made with the 6351 alloy should be OK with eddy current testing. Getting them serviced and universally filled is the snag.
Pete
I think in early 1988 is when most Luxfer tanks switch to 6061-T6. Some of the early 88 tanks were 6351-T6 (the exact tank models and when they switch can be found in Luxfer web site).
I have heard that some dive shops are even using 1990 as the cut off year. The story is to avoid confusion with their employees they are rounding to 1990. I think that is very irresponsible, but it is hard to argue with ignorance.
In any case the OP said: which have not been hydroed since 1989. It kind of implies that it was not the first hydro, plus I think that US Diver Aqualung 80 cu ft Professional Aluminum Tanks was an earlier US Divers tank label. If I recall correctly they introduced the Professional Aluminum Tanks in the mid to late 70s.
The bottom line is that only the first hydro date will help determine the tank material.
With todays trend, I wouldnt touch them if it is pre 1989. Actually I probably wouldnt touch anything pre 1990.
I have heard that some dive shops are even using 1990 as the cut off year. The story is to avoid confusion with their employees they are rounding to 1990. I think that is very irresponsible, but it is hard to argue with ignorance.
In any case the OP said: which have not been hydroed since 1989. It kind of implies that it was not the first hydro, plus I think that US Diver Aqualung 80 cu ft Professional Aluminum Tanks was an earlier US Divers tank label. If I recall correctly they introduced the Professional Aluminum Tanks in the mid to late 70s.
The bottom line is that only the first hydro date will help determine the tank material.
With todays trend, I wouldnt touch them if it is pre 1989. Actually I probably wouldnt touch anything pre 1990.
mike_s
Contributor
candudave:
The reason they are cheap is most likely they are made originally before 1988 and made of 6351 Alloy.
If you buy them, good luck finding a dive shop that will fill them.
I used to be of the opinion that there was nothing wrong with these tanks if properly inspected. There was a recent explosion in New England of one of these tanks and another recent "cracking" while filling by a shop that filled them. I actually saw the 2nd tank. It was just back from hydro and passed an Eddy Current exam, but cracked the next time it was filled. You could see the crack afterwards (after the fill) with your regular eyesight. Luckily the tank only had a hairline crack in it and just created a huge leak and they opened the valve quickly to vent pressure off and no one was hurt.
needless to say this shop doesn't fill 6351 tanks after this anymore. I can't blame them either.
I have 3 of them and I've never had a problem getting them filled. I always get an Eddy Current check on them every year and I've never had anyone refuse to fill them.
Jeepman3sk
Contributor
I don't think there are any shops in New England that will fill pre 88 tanks anymore. I just received an email from my shop about this. Get a 90 or younger tank.
Similar threads
