What to look for in a new SCUBA tank?

[paperdesk]

Thank you! Very helpful info!

Ted

Take a look at the manuf date on the tank. It will be stamped on the neck. It should be xxAxx the first 2 xs are the month and the second two are the year. The thing that looks kinda like a capital A or maybe an up arrow is Luxfers hydro mark. You must have the tank hydroded every 5 years, reguardless of when it is sold so it is quite possible to get a "new" tank that may need a hydro in just a couple of years. Hydros can be expensive - around $50 for vip/hydro/fill around here so IMO every year old the tank is, it's "new" value drops by $10.

 

[JasonE]

The real question is if you need a tank at all. I bought one right after I got certified because I don't like to rent. The problem is that I didn't know about Visual and Hydrostatic inpections...more to the point, I didn't realize the cost of said inspections.

Look at it this way:
The rental fee at my LDS is $10 for a tank. The price to fill a tank is $8. Right there I would have to get 80 fills just to break even on the cost of the $160 tank. But, you also have to add on $15 yearly for a visual inspection and $60 every two years for a hydro.

Your numbers may be different, but you should consider the whole picture before buying a tank. If you do tons of local diving or you really don't have a dive shop nearby to rent, then it may make more sense to own one. For me I found that it wasn't worth it and ended up donating it to the college scuba program.

Are you saying that your LDS only charges $10 for a tank rental - INCLUDING gas?

Hydro's are every 5 years.

For most people the convenience far outweighs any cost advantage or disadvantage.

Get two tanks minimum - you'll regret not having a second.

 

[SC_Hoaty]

Good question Brian. No, I hadn't considered a steel. Should I?

Lots of folks think so. I have Al, but know more now.

Steel will last for many, many years if kept dry (rust is the big killer).

Steel is always neg. bouyant, where Al goes from neg. to pos. (Hard to add weight underwater when you find you are getting floaty.)

Some steel is rated for higher pressure. This may impact your choice of reg set.

Some folks are pro-DIN also. Depends on the diving you do.

Good for you for asking advice before you buy - I just bought something like what I had always rented, and then learned more. Wish I had known about Scubaboard then!

 

[jashaw]

Good point Chris. Unfortunately I'm in a very rural location. I have a 1.5 hour drive ONE WAY to get to the closest rental location, which comes to about $40 just in fuel, plus of course the time . . . . Otherwise I'd be much happier to rent.

I hear ya on that one. The closest shop is about a half hour away, but they are only open on certain days. So the closest shop that is open 6 days is an hour and a half one way. I found used tanks on the radio, but you are not looking for used tanks.

 

[tregrrr]

Are you saying that your LDS only charges $10 for a tank rental - INCLUDING gas?

Hydro's are every 5 years.

For most people the convenience far outweighs any cost advantage or disadvantage.

Get two tanks minimum - you'll regret not having a second.

there is a local operation in Vancouver (BC) who rents tanks for 15$, and if you bring it back in your 24hr rental period, they will refill it free.

so it is possible to save money renting tanks (2dives owning =20$ fills, vs 15$ renting with two fills) The economy however gets lost when you consider that that shop (or all of them around here) are 15 miles and up away from normal dive sites... so you spend more in [truck]gas getting your [dive]gas.

It is a nice touch I must say though... it allowed for a dive around noon, dinner and fill in the city, and back out for a night dive with tank return in the morning.... until I bought my own steel tanks.

TO OP:
The nice benefits of steel versus aluminum are:

• Steel has larger capacities available (a 100cf steel is the same physical size as an al80) and that extra 25% is really noticeable.
• Steel will last longer: Some shops (THROUGH POLICY) CHOOSE to not fill Aluminum tanks older than 20 years old. (I personally think that policy is bunk... If the tank is checked out and certified... what is wrong with filling it?? and yes I do fill tanks!! ) and there are industrial steel cylinders currently in use over 100 years old
• Steel tanks allow you to shed some lead off your belt because at the end of the dive, aluminum cylinders will want to float (by 4lbs) while an empty steel will still sink (1-2lbs negative) You no longer need to carry the 4 extra lbs of lead you would need to counter the empty aluminum tank.
• All the cool kids have steelies up here in the PNW (or PS_outhW from a Canadian viewpoint)

TWO advantages for aluminum:

• Cheaper initial purchase
• somewhat more forgiving of abuse

 

[elmer fudd]

Most divers here in the NW strongly prefer steel tanks. They're much more compact and negatively buoyant, which means you don't need to wear as much lead and you have your choice of either a wearing a smaller tank or carrying more air. My HP119's for example hold over 50% more air than an AL80 and are about 3/4" wider and 2" shorter than an AL80. Being big tanks, they weigh 41 lbs empty, while an AL80 is about 32 lbs, but since they are 6 lbs more negatively buoyant, I'm only packing about 5 lbs more total weight at the beginning of the dive, but I've got a heck of a lot more air to show for those 5 lbs.

Now if you were to go the other route and get an HP80, you'd have a tank that's the same diameter as an AL80, but 6" shorter, 4 lbs. lighter, 6 lbs. more negative and still holds more air, (AL80's actually hold 77 cf of air while HP80's hold 80 cf).

So why would anyone go with AL80's? Well, there's cost for one. They are the cheapest new tanks you can get into. Also, not everyone wants the negative buoyancy of steel tanks. Not everyone dives in cold water with drysuits or 7mm wetsuits. For a warm water diver wearing a 3mm or a dive skin that negative buoyancy is a liability. The same logic applies to pony bottles. Since aluminum ponies are basically neutral, most divers prefer them to steel ponies. It's easier to keep your weighting right that way.

Now if you're just looking for cheap dive gear, there is one other attractive option out there: LP72's. These are old steel tanks that can generally be found for $50 or less, (I wouldn't pay more than $25 myself). After a hydro and vis and you're looking at about $85 to get a dive ready tank. With a 2200 psi fill, they hold about 66 cf of air. I know of a couple of shops that will give me 2500 psi fills though and if you know someone who will fill to 2700 psi you've got the same capacity as an AL80. So long as they pass vis and hydro, steel tanks are good forever.

Aluminum tanks that pass vis and hydro are technically good forever too, but there were some made of a bad alloy back in 70's and 80's and many shops just plain refuse to fill any old aluminum tanks.

 

[Amphiprion]

Have you considered buying used from the scuba store rental tanks? I purchased double LP 98 steels this way and may consider finally buying an AL80 for deco. Saved me at least a couple hundred bucks and they seem to work fine. Hydro and vis are up to date.

 

[paperdesk]

I really appreciate the insightful replies! I love the idea of LP72's. I go pretty easy on my air, so a smaller tank would probably work out just fine for me, and at this point I really don't do enough local diving to make a large investment worth it (unfortunately). I wish I lived closer to the ocean, then I'd be tempted to do a lot more diving!

Amphiprion, first of all, great choice on a user name! Love it. Yes, I checked around, but so far I haven't found a lot of used gear. The one shop that did have a used AL80 wanted $140 for it which didn't seem like a steal somehow . . .

 

[elmer fudd]

What I do is scan Craigslist on a daily basis. Just type in "scuba" in the search field. I'm not seeing a lot of LP72's right now, but if you check on a regular basis you'll see them pop up twice a week or so.

This ad has two of them for $60 each. A little high IMO.
Scuba Tanks - great condition- 4 available

Here are two mystery tanks, $40 for the pair. That's a good deal for steel tanks, but not so good if they're 80's era AL80's.
2 scuba tanks

And here's a newer LP98 for $100. That's a good deal on a big heavy tank.
steel tank for scuba diving

You'll likely find a few more in the Portland area. A few things to look for on these old tanks. First, remove the boot and make sure it's not too badly rusted. If it fails vis it's just junk. If you can, (unlikely), remove the valve and look inside. Lastly, some of the really old tanks were made with 1/2" valves. These are probably of more value to vintage divers, but in practical terms it means you'll be limited to using really old valves.

My two 72's both came with J-valves, but I replaced those with K-valves from some of those old AL80's that no one wants.

 

[Stu S.]

Good idea to buy instead of rent. Tanks have a high resale value compared to other SCUBA items. A used wetsuit or BC doesn't bring much, but you can buy a new tank and sell it years later for almost the same amount.

I bought a used aluminum tank and sold it for more than I paid. I owned a steel tank for two years and sold it for $20 less than I paid. I wish a car held value that well.