Explain to me why you own your own tank(s)

[Mr_D]

Amigos in cave country is 24/7 self-service fills of EAN32, air, O2, and helium

I did a Google & YouTube search on retail self-service scuba tank station and found nothing. How does this work and how do you pay?

 

[mcohen1021]

cost of a fill is $F, and the cost of a rental is $R, and the cost of an annual visual tank inspection is $V. Then your total cost for the year is
$T = N($F+$R) + $V
Typical numbers are $F=$8, $R=$10, and $V=$25.
For N=10 you spend $180 if you rent, $125 if you do not.
For N=100 you spend $1800 if you rent, $1025 if you do not.
For doing not much diving, it takes a while to amortize tank ownership.

But you did not take into consideration the cost of the tank itself and the hydro test every 5 years...

What if they decide your tanks were made of inferior materials and are doomed to explode mid-dive, and condemn them forcing you to buy new tanks like they did before?

I do have a tank, but a friend gave it to me... And it's nice to be able to strap it on and jump to the bottom of the lake if I need to do some work

 

[Boarderguy]

But you did not take into consideration the cost of the tank itself and the hydro test every 5 years...

What if they decide your tanks were made of inferior materials and are doomed to explode mid-dive, and condemn them forcing you to buy new tanks like they did before?

I do have a tank, but a friend gave it to me... And it's nice to be able to strap it on and jump to the bottom of the lake if I need to do some work

How often does that happen when it is not a direct reflection of the neglect you've bestowed upon it? Steels will need to be tumbled every once in awhile. AL will last 50+ years of you keep up with them, but some shops refuse anything older than 20 years for no valid reason.

Your tank won't be condemned by anyone other than the hydro shop and that is only after it has failed. If they fail it because they did not follow procedures for a galv steel tank then you can have them replace it.

Tanks don't just go bad lol

This is like saying you shouldn't buy a car because the tires might go flat.

 

[mcohen1021]

Tanks don't just go bad lol

This is like saying you shouldn't buy a car because the tires might go flat.

I understand that, and I agree.. but there was a time where they condemned all the tanks prior to I think 1992? I could be wrong on the year

They deemed it as inferior materials

 

[Boarderguy]

I understand that, and I agree.. but there was a time where they condemned all the tanks prior to I think 1992? I could be wrong on the year

They deemed it as inferior materials

I have a few of those and they are still in use. They just require an additional test AND a shop that understands they're not bombs.

 

[mcohen1021]

I called three or four shops in my area and no one would touch them with a 10-ft pole

I don't really care so much because I don't do any local diving anymore except for when I'm asked for help

 

[Belzelbub]

I understand that, and I agree.. but there was a time where they condemned all the tanks prior to I think 1992? I could be wrong on the year

They deemed it as inferior materials

It was 1988, didn't affect all tanks. And even those that were affected were not immediately condemned. There was just additional testing that had to be done in order to be used.

Now, what happened was that some shops used that date, rounded up, and said all AL tanks produced prior to 1990 couldn't be filled. Despite the fact that Catalina, for one, had never used the alloy that was the problem. Other shops took an even weirder approach. Some just adopted a 20 year rule, and never updated it. Their shop, their rules, but some common sense might be good here.

I've got two AL80s. One from Catalina, one from Luxfer. Neither is made of 6351, but both are old enough that the 20 year rule would be a problem. I've never had a problem getting them filled.

That said, there is another issue that comes around every few years. Cylinders made under a special permit/exemption need to have that renewed every 7 years or so. PST made a bunch of tanks that lots of divers love. They no longer do, and no longer exist, so sometimes the renewal falls through the cracks. Last time was sometime last year, and it took someone from SB to contact the current owners of PST and they rectified the problem. IIRC, DOT was also looking into ways of renewing the permit as well. So, I'd say it's something to be aware of, but not really something that's happened frequently.

 

[KenE]

One reason is that I want a tank at home of clean air so I can work on and check out my gear.
I may also be driving somewhere so that the logistics are simplified with several of my own tanks.

You apparently dive and fill locally. Depending on where you live and how much you dive, that can get expensive compared to having your own tank(s). The fundamental idea is that filing is cheaper than filling plus renting. Example: suppose you do N dives per year, and the cost of a fill is $F, and the cost of a rental is $R, and the cost of an annual visual tank inspection is $V. Then your total cost for the year is
$T = N($F+$R) + $V
Typical numbers are $F=$8, $R=$10, and $V=$25.
For N=10 you spend $180 if you rent, $125 if you do not.
For N=100 you spend $1800 if you rent, $1025 if you do not.
For doing not much diving, it takes a while to amortize tank ownership.
For a lot of diving, it take just a few months.

I believe the fill cost should be removed from this equations because that cost is the same in both situations. The comparison is only the cost of vis and hydro vs renting. The cost of the cylinder is recovered upon sale or amortized over the life of the cylinder which would be a very small cost considering the number of dives/years one can get from a cylinder.

In my case I dive several hours from home and I don't have a LDS where I live, there is one near the dive sites. So, a trip to the LDS before a dive is not feasible. I get the tanks filled after the diving while the dive team does our usual debrief at local restaurant. My tanks are always full waiting for the next dive opportunity that arises. I also use larger tanks then those readily available for rent.

 

[tursiops]

I believe the fill cost should be removed from this equations because that cost is the same in both situations.

You can usually fill your own tank cheaper than you can rent a full tank. that is why I calculated it the way I did.

 

[Tracy]

Tons of various gear is impossible to rent. A 2L steel O2 bottle with a top post valve? Forget it.

I have several for rent, same with 3L and 4L. Swing by.