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Old 07-08-2011, 09:57   #1
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Aluminum vs Steel Dive Tanks

Why Al 80's yeeck! I changed to steel and have never looked back.
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Old 07-08-2011, 10:04   #2
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Re: SCUBA Tanks 80cfm Aluminium

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Why Al 80's yeeck! I changed to steel and have never looked back.
What steel tanks do you use? The old steel 72s or something newer? And why not Al 80s? I've got 12 steel tanks and 15 Al tanks and use one or the other depending on the situation.
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Old 07-08-2011, 10:46   #3
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Re: SCUBA Tanks 80cfm Aluminium

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What steel tanks do you use? The old steel 72s or something newer? And why not Al 80s? I've got 12 steel tanks and 15 Al tanks and use one or the other depending on the situation.
what situation would you use one vs the other?
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Old 07-08-2011, 10:47   #4
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Re: SCUBA Tanks 80cfm Aluminium

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Why Al 80's yeeck! I changed to steel and have never looked back.
whats wrong with AL80'S?
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Old 07-08-2011, 11:26   #5
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Re: SCUBA Tanks 80cfm Aluminium

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what situation would you use one vs the other?
A couple of comments. A Luxfer Al 80 is just a couple of pounds negative full, about a pound positive when empty so situations where I want neutral buoyancy and minimal weight swing during the dive I use the Al 80. Also, Al you don't have to worry about corrosion diving in salt water.

I think the preference for steel tanks is mainly because you can get more gas in the tank and being more negative you can take some wt off the belt. This is good within certain limitations.

My take.

Al tanks

- Warm water diving without wet suit. I don't need a weight belt at all, in fact I've even dove with just a harness and no BC and maintain buoyancy with breath control.
- To carry extra gas in tech diving. I use to do cave dives using double steel back tanks and carry up to 4 Al 80s for the extra gas. Steel tanks would be much too heavy and negative for this.
- Al 40s to carry deco gas in deep wreck dives. Small, easy to carry and have sufficient gas for the deco.
- Al 80s in most ocean dives to keep my steel tanks out of salt water.

Steel tanks

- You can get much larger steel tanks. Up to 120 cu ft, Also most people overfill the steel tanks so can (safely) get about 15-20% more gas than their rated capacity.
- the old steel 72 is low pressure rated so for O2 fills from a cylinder cascade you can get more oxygen than a 3000 psi Al 80.
- If you have them the old steel 72s are light wt, slightly negative and will last forever. But you have to make sure you keep the inside dry, especially if you dive in salt water. Problem is I don't think you can get new steel 72s
- Diving dry suit you need a LOT of weight so I use steel tanks to keep the weight belt smaller.
- Have used a steel 90 cu ft ocean diving with a wet suit, again to keep less wt off the belt. Just make sure that with the tank you are still slightly positive with the tank full. You should need at least some lead on the wt belt to be negative so you can ditch and be positive in an emergency.
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Old 07-08-2011, 11:32   #6
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Re: SCUBA Tanks 80cfm Aluminium

Thanks Skipmac. great answer.
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Old 07-08-2011, 15:39   #7
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Re: SCUBA Tanks 80cfm Aluminium

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Why Al 80's yeeck! I changed to steel and have never looked back.
because... steeltanks are to heavy and- much more expensive, thats why. more then happy with al tanks.as long someone is not into tek diving and needs 300bar pressure, al is fine.
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Old 07-08-2011, 19:41   #8
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Re: SCUBA Tanks 80cfm Aluminium

Buoyancy is the main issue, and I get the insides cleaned and coated quite often. I do dive Tech, but the Al metal is much more reactive, and I prefer not to breathe air that has been pressurized in it. I don't like rusty tanks either, and I refill at state of the art facilities with filtered, analyzed air,nitrox or mix. No I have not seen anybody die from Al tanks, but I have seen some nasty accidents due to positive buoyancy at the end of a dive. My son almost bit it when his dive belt fell off, but that is a topic best left for scubaboard.
BTW, I dive with 72's, sometimes twins and 80's and 120's, all steel. I may drop them all for a rebreather in the future. I dive wet (warm) and dry (cold).
In the end it might just be that I trust what I know. All the anesthesia tanks and oxygen tanks in every hospital I have ever worked in were steel. I treat my tanks as life support gear, and I am very anal about them. If you get the bends on my boat, you will get oxygen from a steel tank. It has a long track record and is worth the expense in my experience. Feel free to dive with what you want, its your lungs.
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Old 07-08-2011, 19:51   #9
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Re: SCUBA Tanks 80cfm Aluminium

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Buoyancy is the main issue, and I get the insides cleaned and coated quite often. I do dive Tech, but the Al metal is much more reactive, and I prefer not to breathe air that has been pressurized in it. I don't like rusty tanks either, and I refill at state of the art facilities with filtered, analyzed air,nitrox or mix. No I have not seen anybody die from Al tanks, but I have seen some nasty accidents due to positive buoyancy at the end of a dive. My son almost bit it when his dive belt fell off, but that is a topic best left for scubaboard.
In the end it might just be that I trust what I know. All the anesthesia tanks and oxygen tanks in every hospital I have ever worked in were steel. I treat my tanks as life support gear, and I am very anal about them. If you get the bends on my boat, you will get oxygen from a steel tank. Feel free to dive with what you want, its your lungs.

i sure do mate, don't see a problem with al tanks. i did over 5000 dives with al tanks and - my lungs are fine..... if you inspect the tanks and clean them there is no rust inside, don't know where that idea comes from. at least when there is a proper water separator and filter on the compressor there is no rust in a tank.
anyway- i still looking for used tanks ......... lol
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Old 07-08-2011, 20:24   #10
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Re: SCUBA Tanks 80cfm Aluminium

And I did not mean to hijack your thread, rather let you know there were options. Good luck with your search.
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Old 07-08-2011, 20:34   #11
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Re: SCUBA Tanks 80cfm Aluminium

I dive Pressed Steel High Pressure 100's... haven't used an aluminum tank in a decade. Faber is also good...

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What steel tanks do you use? The old steel 72s or something newer? And why not Al 80s? I've got 12 steel tanks and 15 Al tanks and use one or the other depending on the situation.
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Old 08-08-2011, 11:28   #12
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Re: SCUBA Tanks 80cfm Aluminium

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....scubaboard....
And people think there's drama here at CF.....LOL......
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Old 08-08-2011, 12:40   #13
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Re: SCUBA Tanks 80cfm Aluminium

Well...the weight difference is caused by the amount of air you use. Steel tanks get lighter too. Take 6 pounds (not psi but actual weight) of stuff out of any tank.....and its 6 pounds lighter. Adjust your buoyancy with 500 psi in the AL tank and its not an issue :-)
BTW I was diving the Oriskany yesterday...boy does she need some bottom paint.LOL
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Old 08-08-2011, 15:23   #14
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Re: SCUBA Tanks 80cfm Aluminium

300 Bar...thats some seroius pumping. Its nice to see a fellow techy here. All the twin sets at Cobolt Coast in Cayman are aluminum. I like steel stage cylinders because they dont float up in your armpits when empty during the deco stops. Wow way off topic.....
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Old 08-08-2011, 15:56   #15
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Re: SCUBA Tanks 80cfm Aluminium

You can more often find steel tanks which have higher pressure ratings than aluminiums. We have some Draeger babies - sit nicely on a rebreather, which is where they're from (but gonna ditch those, they're a pain) - which are rated to 300 bar so also contain 80cuFT. Think they're about 8 litre, but would have to go check.

The point is, they can hold the same amount of air as an ALi 80cuFt (11 litre @ 207bar), and take up waaaay less space on the boat.
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