Free tanks worth it?

[Elonna]

OK, maybe I'll still check with a couple of the local shops. If someone is willing to inspect and test them...and everything checks out ok and will then fill them...should I not be worried about using them? Someone told me they were only known to crack during filling...what are the chances if they pass testing, that they might crack at 60ft?

 

[rstofer]

When I thought my Luxfer 80 might have been made of 6351, I thought long and hard about what I would do. After all, there are millions of these tanks still in service. It's not like they're exploding like popcorn.

OTOH, it's just a hunk of aluminum. A hunk with a tarnished reputation. Would the cost of replacing the tank with a brand new one (say $150) make any difference in my life?

While I might feel like the 6351 tanks are perfectly safe when inspected as required, it only takes one explosion to mess up your entire life. Whether you are there or not. For $150?

So, I had decided to scrap the tank but thought I would check first. Turns out it is 6061 and of no concern. But it's older than 1990 (or some magic LDS established cutoff date) and when the shop doesn't want to fill it, I'll scrap it. After all, I paid about $100 for the tank 20 years ago. I really can't get excited about the loss.

Personally, I would scrap the 6351 tank just to get it out of the fleet. I would talk to the shop about the S67 tank (after I confirmed with Luxfer that it really is 6061) and see how they feel about filling it. If they have heartburn, I would scrap it as well.

But I want to reiterate, this is what I would do. Aluminum tanks aren't all that useful to me. I am sure others would make the case to keep and continue to use both tanks.

Richard

 

[diverdoug1]

OK, maybe I'll still check with a couple of the local shops. If someone is willing to inspect and test them...and everything checks out ok and will then fill them...should I not be worried about using them? Someone told me they were only known to crack during filling...what are the chances if they pass testing, that they might crack at 60ft?

Elonna, I have never heard of this happening. I would think tanks would be less likely to rupture when submerged. If you are still concerned about using these tanks, I am sure you could easily find another diver who would be happy to purchase them at a reasonable price. I would dive them if they passed all appropriate inspections.

 

[LeadTurn_SD]

OK, maybe I'll still check with a couple of the local shops. If someone is willing to inspect and test them...and everything checks out ok and will then fill them...should I not be worried about using them? Someone told me they were only known to crack during filling...what are the chances if they pass testing, that they might crack at 60ft?

Hi Elonna,

My understanding from reading is that the crack(s) are thought to be there long before the tanks ruptures, are quite visible during inspection; and the few that have rutpured were ones that had not been properly inspected, thus the crack(s) were not detected.

I have not heard about a tank rupturing during a dive.... I'd guess it would be most likely to rupture during filling, when the most stress is being placed on it. Others may chime in if they've heard otherwise.... and I believe it is only a handful of the "bad alloy" tanks that have ruptured (something like 9 or 10 total? I don't remember).

Best wishes.

Ouick Note: Richard makes some really good points above. If the shops in your area express any strong concerns, it may just be better to buy new, or new "used" tanks. It will save you headaches.

I did check my "old" 1978 Al80, and now I'm not sure of it's real origin (or alloy).... the manufacturer's stamp is "USD" (US Divers).... not sure if Luxfer made tanks for them during that period.... I'll have to check into it.

 

[FredT]

The 67 has a short necked K valve, the photo on the tall one isn't clear but probably matches.

DOT has an inspection procedure that is MANDATORY at hydro for those tanks that permanently marks the tank neck condition and date on the bottle. The rub here is that many hydro testers haven't set up to do it yet. Before I drilled holes or destroyed the threads on those I'd wait a while to see how this falls out in the wash. In any case the price for AL scrap is in a trough right now so holding on to them a year or three if you have storage space may be a wise thing to do.

To pull the valve all you need a large adjustable wrench and a rubber hammer.
Step one is to open the valves until they stop loosing air.
Then open the valve farther and see if they loose more.
Once the things are empty place the wrench on either the hex at the bottom of the valve, just above that on the body, or if neither of those will take a wrench, with one jaw on the o-ring surface and the other where the yoke screw contacts the valve.

Rap the wrench handle sharply with a rubber mallet or chunk of wood until the valve moves about 1/4 turn. Then lose the wrench and unscrew the valve by hand.

The first step of the inspection process is to invert the tank on a piece of paper and tap it on the side lightly. Remove the tank from the paper and see if anything came out. If less than a quarter teaspoon of stuff comes out you should be fine to move on to the next step.

BTW it's perfectly fine to store an AL bottle empty without the valve installed, or without the valve reinstalled and not filled provided the next step is to service the bottle before use. I have several empty AL bottles in my garage "waiting for service." This "store dead empty is OK" thing does NOT apply on any steel bottle!

Tank maintenance is a long way from rocket science, and the adventure of learning about those 2 will be worth the effort for what you gain. Even if the tanks turn out to absolute junk with internal corrosion and badly cracked necks (not likely) just the calibration of your LDS BS meter will pay of many times in your future diving career.

 

[Wayward Son]

it really is shop dependent. I have a buyer for my 100's, but he went to every LDS in his area until he found one that would service & fill them. Once he was sure of that, he was ready to buy them.

Until then, not so much. A deal on the tanks is no deal at all if you can't use them.

 

[DaleC]

Tank maintenance is a long way from rocket science, and the adventure of learning about those 2 will be worth the effort for what you gain. Even if the tanks turn out to absolute junk with internal corrosion and badly cracked necks (not likely) just the calibration of your LDS BS meter will pay of many times in your future diving career.

Well said Fred!

Elonna, as divers we have to learn how to assess information rationally and act accordingly. It's no good knowing what the shops in Florida do if you live in Cincinatti or that some people prefer steel to aluminum. A well maintained and serviced Al 80 can serve you, or someone else, for many many years to come (if the fill issue does not apply to your region).

You have all the info you need to make your decision:

1. Look up the cylinders on the Luxfer list.
2. Circle your numbers, print off the list and, with cylinders in hand, go to your LDS (the one you will use regularily) and ask if they will fill the cylinder if properly serviced.
3. If they say yes, get them to service the cylinders (they will feel a lot better if they control the inspection).
4. If they say no, listen and consider their reasoning.

It may be that the tanks are corroded or damaged or that shops in your area will give you an unending battle over older tanks... or it may be that those tanks are fine and will be readily filled.

If they reject the cylinders out of hand you at least know the state of critical thinking in that shop. It may be the same shop that tells you you need new hoses when a 1 cent O ring will do or that your regs should be replaced because they have scratches on the dust cover.

Dive them or don't dive them, it's up to you but remember:
the retail dive industries survival is based on convincing the consumer that the bomb proof, very safe, long lasting gear they own is in need of constant replacing.

The odds of a 6351 tank letting go due to SLC (about 12 in 25 million).
The odds of a properly maintained and serviced 6351 tank letting go (so far 0).
The odds of you dying in a car accident (about 1 in 83).
The odds of an older 6061 tank letting go due to SLC (so far 0).

 

[ScubaInChicago]

Hi Elonna,

I talked to my LDS for quite a while and they explicitly told me that they knew about the problems associated with the Luxfer tanks. They stated to me that as a reputable shop, that if they performed the VIP Eddy and Hydro and everything passed, they would happily fill the tanks. They stated that all reputable shops that performed the same service should also fill your tanks for you. They also stated that the extreme stresses on the tank are at hydro where they pressurize the tanks to a min 5000 PSI to check the integrity and water displacement and would not pose a problem at a 3000 PSI fill.

Hope this helps to encourage you to find a LDS that will work with you.