Aluminum vs Steel & why?

[NC Wreck Diver]

I can mix it up here. I have a set of Steel Farber 85 doubles, a set of AL 80 doubles and a set of AL 63 doubles. I obviously like the steels in cold water, but I dive the AL in cold water too. I have this variety of tanks because when I started diving in the mid 80's, AL was new to diving, and that is what you bought. Yes, they are the suspect alloy, but I have them VIP'ed and Eddy current tested every year, and all hydro's have been fine. I'm running out of room for the stamps! I am not afarid of the AL tanks, since all testing has been fine. I did a lot of investigating this issue over AL tanks. The 13 AL tanks that they had a problem with were mostly for SCBA (for firefighting), and a few were SCUBA tanks. What I found out is that the smaller pony bottles were more of a problem then 80's & 63's. So when they fail hydro, I will replace them with steel, but I will dive the AL as long as they pass all tests. Strange to be in two camps..............

 

[fl-diver]

Sounds like you are pretty new to diving. (0 -24 dives) I dive warm SE Florida water for the last 20 years and switched to steels just a couple years ago. I think steels are better way to go no question. Even if you use the steels with no extra weight it is worth it in my opinion. Things to consider as you get more dives under your belt:

- steels typically give you more volume for the same tank size. HP100 is smaller than aluminum 80.
- more likely to get good or overfills. (Especially on LP tanks)
- as you dive more you will probably go deeper and want more bottom time.
- If you are diving nitrox most places charge 1 fee regardless of tank size. So it costs the same to fill my HP 120 as an alum 80. If diving shallow 60' or less I can get 2 dives on one tank. (This pricing may be a regional thing.)
- Steels are better!!! JK As a new diver diving on air alum 80's are fine.
- Look for good steel tanks on craigslist. I found a great deal a few years ago on 4 HP 100's.

 

[Jax]

Steve, do you know what you want from your tanks?

I wanted something comparable in land-weight to the AL80s one always finds to rent, but I wanted more gas. Also, the AL80 was a little long, and I had to stand up to fasten my harness. I went to TDL Tank Specs and found the Worthington and PST steel 100s were comparable for out-of-water weight and size.

However, in water, the steel's buoyancy characteristics are quite different. The center of balance is further up and leave me slightly foot-floaty. YMMV.

 

[Ana]

If you can afford them, go Steel. If they are a financial hardship, go for the Aluminum. Either way, enjoy your dives!

I think that is a wise suggestion.

The thought that shallow warm water diving doesn't benefit from steel is arguable.

1- If all your dives are in what is generally considered "warm water", chances are that your tolerance for cold is somehow compromised, and you'll require more thermal protection during colder days, even if cold water people laughs at that. Hence the presence dry suit divers in South Florida when the temperature threatens to dip below 70 degrees.

and

2- If all your dives are shallow (above 30 feet or its vicinity) the second half of the dive, which has the potential to last for hours, will be subjected to great buoyancy changes. Not impossible to deal with that but I believe it would be smoother using steel.

If you add shallow and warm water, steel can be just as good or better.

I suppose the cost and the weight ditch-ability are the 2 main factors.

I dive steel with a bp/w. Only use a weight belt when temps go bellow 75. Works for me.

 

[ONESPEED]

Also, the AL80 was a little long

Is the tank too long or are you too short?

 

[LowVizWiz]

Your diving and your budget dictates what you should get. If you're beach diving a lot it may not make a lot of sense to buy big steel tanks, but if you're planning on doing deeper dives it doesn't make much sense to use an AL80 either. The weight issue is actually secondary to your gas requirements!

I prefer diving steel tanks, but I'm rather tall and hooverish! I also own a pair of AL tanks for the occasional shallow or beach dive.

If you look around a bit you can find bargains on both AL and Steel tanks (as long as they are not steel 130s and Brian is around )

So what's your diving like?

 

[herman]

I have a couple of 25 yo AL80s and a couple of 15 yo AL80s and they are still going strong. I'm OK with them, and replacing them is not in the budget. The disadvantage of the Aluminum tanks is that as you breathe them down, they become more buoyant and if not properly weighted from the get-go, you may find yourself floating up at some point in your dive. I'm a kayak diver, and I usually stay down until I have only about 200 psi left, so I am always overweighted at the beginning of my dive.

If you can afford them, go Steel. If they are a financial hardship, go for the Aluminum. Either way, enjoy your dives!

This seems to be a big misconception for a lot of divers. There is no difference in buoyancy shift in equally sized tanks reguardless of the tank material. The change in buoyancy of a steel 80 and an AL 80 is exactly the same, you use the same amount of gas from equal sized tanks so the buoyancy shift must be equal as well. Granted the amount of weight you need to achieve neutral buoyancy is different but the shift in buoyancy from full to empty on equal volume tanks is the same.

 

[Rhone Man]

Aluminium.

Most people here will suggest steel, because for long term serious divers steel is the better bet, so that is what they would get.

No offence, but most new divers drop out of the sport after a short while, and an Aluminium tank is a much smaller investment to walk away from. Or better yet, just rent tanks for a while.

 

[DebbyDiver]

This seems to be a big misconception for a lot of divers. There is no difference in buoyancy shift in equally sized tanks reguardless of the tank material. The change in buoyancy of a steel 80 and an AL 80 is exactly the same, you use the same amount of gas from equal sized tanks so the buoyancy shift must be equal as well. Granted the amount of weight you need to achieve neutral buoyancy is different but the shift in buoyancy from full to empty on equal volume tanks is the same.

Very interesting, thanks! I've only rarely dived steel tanks since going AL in the early 80's so my statement was anecdotal, not personally experienced.

Like what weighs more, a pound of lead or a pound of feathers.

 

[reefman]

my preference are 100 high pressure steels. here's an informative link from fill/divegear express in pompano beach,,,,,,,,


How to Select a SCUBA Tank - Dive Gear Express


reefman
key largo