True cost of ownership?

[Crush]

Hello all,

I am toying with the idea of getting a pony bottle and tank (currently I rent). I realize that there are many non-financial benefits to ownership. However, restricting the discussion to a monetary one, can anyone give me an idea of what the average annual maintenance fees associated with owning one's own bottle? To keep it simple, assume Al tanks (not SS). Obviously prices vary, but can you give me a general idea? For example:

1. What does an annual visual inspection cost?
2. What does a hydrostatic test every five years cost?
3. How long should a pony bottle last? Five years, or more like 20 years?
4. Are the burst disks replaced annually? What does that cost?
5. NAUI suggests that it is not a good idea to keep one's bottle charged. Is this the case, or does not really matter? Or would keeping the bottle charged lessen its lifetime?

Thanks!

 

[Diveral]

I don't know how much dive related costs are in Canada but here's my answers for Alabama.

1. About $14 including nitrox fill
2. About $35-$40 including visual inspection and fill
3. Long, long time
4. No, don't know I've never replaced one and I've had my oldest tank since 1981
5. I always keep my tanks charged. I like storing them with 500+ psi in them.

 

[FredT]

Burst disks in tanks that see salt water should be replaced at valve rebuild, generally done at hydro. Fresh water tanks, maybe every other hydro, but how do yo remember which ones you did last time?

Vips vary. IF you get trained on how to do them, stickers are about .75 each. Training is about a c-note through PSI, depending on instructor and size of the class. Other groups vary.

Hydros can be as low as $10, as high as $75 depending on where it's done and what auxiliary services are performed. This can be as simple as vip and fill, or as complex as full O2 cleaning, valve rebuild and nitrox or trimix fill.

Aluminum tanks seem to have a 20 year regulatory life (even if the bottles last a LOT longer the insurance company lawyers are killing aluminum tanks at about 20 years in the SCUBA industry.) Amortize your aluminum bottles over 20 years right now anyway.

Steel bottles cost a bit more new, and can take a bit more care but can last a century if the inside is kept dry.

OTOH what is the cost of a missed dive opportunity if the shop's not open, or they are out of bottles? The set in your closet filled and ready to go is golden when the unexpected opportunity comes along.

I keep about 30 personally owned tanks (both AL and Steel) current and filled to support my families diving. Costs for me over and above the fills average about $10 a year/tank, including the cost of the tank! I am trained to do VIPs and do my own valve and tank cleaning. The maintenance ops eat a couple winter weekends a year.

 

[brutus_scuba]

Aluminum tanks seem to have a 20 year regulatory life (even if the bottles last a LOT longer the insurance company lawyers are killing aluminum tanks at about 20 years in the SCUBA industry.) Amortize your aluminum bottles over 20 years right now anyway.

Fred, could you please explain to me what you mean by this? I am aware that many shops wont' fill 6351 alloy tanks, but that doesn't mean that we decide to make the lifetime of a tank 20 years as an industry. Catalina tanks have been made without lead since the beginning and are still being filled and you could easily have a 1986 Catalina filled. I have 5 tanks from 1990. I don't suspect I'll have any problem with them next year. They all passed hydro this year.

 

[Couv]

One thing that belongs in the equation is how often will you be using the tank(s). If you will only be using your tank(s) a few times a year, you are probably better off renting. I would suggest to start off with a used tank or two and see how it goes from there. If you find it is not worth it to keep the tanks, you can usually sell a used tank for what you paid for it. As mentioned before, do not buy a really old Al tank. A relatively safe date of manufacture is 1992 and younger.

I just had a few tanks hydro tested and VIP'd and here is what I paid.

1. What does an annual visual inspection cost?
I just paid $5 but no fill included. However, my LDS upon seeing I had it VIP'd elsewhere. informed me that if they would have done the visual ($25) I could have free fills for the year.

2. What does a hydrostatic test every five years cost?
$20 no VIP included

3. How long should a pony bottle last? Five years, or more like 20 years?
Same as any other tank given the same material.

4. Are the burst disks replaced annually?
Usually with the Hydro
What does that cost? ~$5

5. NAUI suggests that it is not a good idea to keep one's bottle charged.
That would be for safety in case of a fire.

6. Is this the case, or does not really matter?
Yes, keep some pressure in to prevent moisture from getting in.

7. Or would keeping the bottle charged lessen its lifetime?
No.

Good luck,

Couv

 

[Stu S.]

The true cost of ownership includes a "surrender value". That's the residual value of the tank when you don't want to own it any more. Many tanks can be sold for 80% of the price of a new one. I had a steel 95 cu. ft. cylinder that sold on eBay for $18 less than I paid new for it. It lost value at a rate of $5 a year.

Wetsuits, fins and BC's have little value on the used market. You can always get good money for a decent tank. That makes ownership a bargain.

 

[spectrum]

Fred, could you please explain to me what you mean by this? I am aware that many shops wont' fill 6351 alloy tanks, but that doesn't mean that we decide to make the lifetime of a tank 20 years as an industry. Catalina tanks have been made without lead since the beginning and are still being filled and you could easily have a 1986 Catalina filled. I have 5 tanks from 1990. I don't suspect I'll have any problem with them next year. They all passed hydro this year.

In some markets all 20 year old aluminum cylinders have been black balled. This conveniently surfaced around here for the 20th anniversary of the 6351 cut-off. One shop in the region offers VIP for 20+ year old aluminum cylinders for something like $120. In other words go away or trade-up. Of course this is wrong but that's the deal.

Other shops will work with the 6351 cylinders if fully inspected including the now required eddy current test. I believe one shop will only fill these if they did the inspection due I assume to the doubts about competence across the marketplace.

Pete

 

[NorthWoodsDiver]

In Minnesota I can expect to pay about:

-free to $8 for an air fill
-$4-12 for a Nitrox fill
-$5-15 for a visual
-$15-40 for a hydro
- ?? service for 02, around here you do it yourself.
an aluminum cylinder should be in theory good for over 100,000 cycles so the lifespan for me doing 100+/- dives a year will outlive me by 950 years or so. A steel cylinder will outlast that if corrosion doesn't get to it first.

Any cylinder made before 1989 by luxfer or any cylinder made by Walter Kiddie ever wouldn't be on the top of my list of cylinders to buy because they used a different alloy of aluminum which has a "past". To keep your life easier buy a catalina or any newer luxfer or any hymark and you will be fine.

Cylinders made from the different alloy are recommend to have an Eddy current test at the time of visual inspection and at hydro its required. That step will up your expense.

Certain special permit productions may be required to be removed from service. this shouldn't affect any newer cylinders used in scuba but a list of these is available through PCI and the manufactures.

So assuming you buy a new tank, from say mike at dive right in scuba (cause he has a deal right now), then your paying maybe $150 delivered +/- for an aluminum 80. It comes serviced for O2 so in case you decide to go nitrox or sell this tank you may wish to keep this up. So a yearly expense for that single tank would run about $20 or less for the visual and fill and then every 5 years an additional cost of up to $40 for a hydro and vis and fill (at which time you may want to replace the burst disc for >$15).

so for 5 years use thats $20X4 + $55 = $135 plus any fills you get. That would be high, it should work out much less depending on location.

If you ran into issues during the vis like deep pits or something in a steel tank well it might require a tumble or may be to far gone to put back in service. If your aluminum tank has a huge deep scratch then it may be removed from service too.

Store your cylinders FULL, this is the safest way to store them besides totally empty which might allow moisture in. In the case of a fire then the safety assembly (IE burst disc) would rupture and safely leak the gas out rather then allow the tank to explode. If you keep say 500 or 1000 psi in the tank the safety assembly might not work as intended and the tank could become a bomb.

I own like 16 tanks or so I think and for me its more convenient to do my own visuals so I got certified. I do my own O2 cleaning and will hopefully be tumbling my own tanks soon too. Technically speaking I fill my own tanks so I dont need a hydro even though I do get them done.

So I say go buy your tanks, get at least 2 primary tanks and you will thank me later.

 

[spectrum]

mpetryk

1. What does an annual visual inspection cost?
$15- $20

2. What does a hydrostatic test every five years cost?
$15 - $30 You can pay more but probably don't need to

3. How long should a pony bottle last? Five years, or more like 20 years?
No less that 20 years. There is some weird paranoia about 20 year old aluminum cylinders right now in some markets. Who knows that the reality will be 2029. Count on 20.

4. Are the burst disks replaced annually? What does that cost?
No, sometimes at Hydro. At some point a valve rebuild may be needed. Usually at a Hydro interval. You can budget $5 a year for valve maintenance but may not spend it.

5. NAUI suggests that it is not a good idea to keep one's bottle charged. Is this the case, or does not really matter? Or would keeping the bottle charged lessen its lifetime?
Aluminum is subject to sustained load cracking and this is probably the root of the statement. Setting aside the old 6351 cylinders this is largely a technical artifact
The one undesirable storage state is 1/2 full. As noted in a fire a full cylinder will trip the burst disc before failing catastrophically. A very light fill should not be devastating when it does fail in a fire.

All things considered you are probably looking at $25 - $35 per year per cylinder to keep things maintained and inspected. An aluminum cylinder will amortize to about $10. a year over 20 so you break even in about 5 dives a year depending on market rates.

The convenience more than offsets the investment. Also as mentioned you can always cash out and recoup some part of the purchase price.

As a Canadian (cold water) diver I would suggest considering steel for your primary cylinder(s)

Pete

 

[helimvee]

Add in the cost of having to drive those rented tanks back to the shop on Monday morning, instead of dropping by with your personal tanks when you are in the area.