Steel vs. Alum (see txt)

[Duca]

Yes, I did a search already.. I figured this topic has been done to death. I searched "Steel aluminum" in the subject field of "Tanks" and all forums. I figured that running either one seperately would just yield many results to wade through.If someone can just post alink here that will answer my questions, that'd be great!

I was told that the steel tanks are heavier and will aid in overcoming dry suit/thick wetsuit bouyancy issues,but that seems to go against what I've read in some threads here.. am I missing something?
Steel tanks seem to be more expensive.
What else should I consider before obtaining either one?

I've noticed that many gear questions come back to "What kind of diving will you be doing?"..so:
I plan on going all the way to instructor and possibly applying it in my career field, Law Enforcement. I will be diving through the winter (I'll own a dry suit by Nov and have a 5mm farmer john now...).
I will be diving the wrecks off the coast of Jersey (hopefully often next year, as I have family and friends who are big divers up there), which lie often lie in 100+ of water.
I will be diving the Gulf as often as possible, it is about a 6-9 hr drive depending on where I end up New Orleans-Biloxi-P City-etc).
My regular "weekly" dives will mostly be in quarries.
There is no active local public safety search & rescue dive team, but chances are that if they start one, I will try to get on it.
I will stick with PADI for most of my instruction, though I have an interest in taking a course or two through SDI and IDEA, at least to try them out. At this point, I don't have the gear flexibility to fall in line with the DIR set-ups, though much of their theory that I have been exposed to interests me... if they have something to say about Steel vs Alum, I'd like to hear it.


I have the opportunity to get two steel tanks at a great price after they have been inspected by my LDS. Is there any reason why I shouldn't jump on them simply because they are steel tanks?

 

[Iguana Don]

Duca,

According to DIR, you only dive steel if you are diving dry. That being said, if the tanks are a good deal and they check out, jump on em.


ID

 

[Duca]

ID,

Can you tell my why DIR states that?

 

[HERB KING]

I own 3 OMS steel 98's and love them. I prefer them over aluminum for several reasons. The main one being they are neautral bouyant when empty, unlike aluminum. As for being heavier than aluminum there is little difference. I opted to the low pressure tanks as they are a little easier on my regs. I dive mostly in the Gulf and Atlantic off Florida's coast and use a back-inflate b/c so being neautral when empty is great for me as they dont tend to push me forward while on the surface. Most dive shops will over fill them to 3000psi also so I can get a little more bottom time with them. I use my aluminum tanks for beach diving now only.
The main things with steels are to never let them go empty as they will rust very quickly. Hope this has helped some

 

[Iguana Don]

Duca,

According to DIR, you must be able to swim your rig up to the surface in the event of a BC/Wing failure.

Due to the characteristics of the two different tanks ie.
Al being more positive as it is used up and steel still being still neg as it is used up.

If you have a BC/Wing failure while diving dry, you still have your drysuit as a back-up.

If you have a BC/Wing failure while diving wet, you only have only your legs as a back-up.

There are those that dive steel when diving wet or dry. And those that dive Al when diving wet or dry. I am sure this is a debatable subject and others will jump in, but this is according to the DIR philosophy.

Hope this helps

ID

 

[JoelW]

There is a bit more than just Al going positive and steel staying negative. You don't have to be able to swim the rig to the surface, you have to be able to get to a state where you can get what remains of the rig to the surface. What has to be tossed in is that a neoprene wetsuit compresses at depth and makes the diver more negative. With a thick suit the loss of bouyancy due to compression can get significant. With Al tanks the diver is more likely to need a weightbelt of some kind, which can be ditched. With steel the diver is likely to need very little extra weight and while wearing a thin suit possibly none.

Now, let's assume that the diver is using the correct amount of weight. Ideally the amount of ditchable weight takes into account suit compression. It is possible that with the steel tank the diver is negative without any extra weight. At depth the bladder fails, or the inflator fails, or something along those lines. With an Al setup the weight belt can be ditched if necessary and the diver swims up. With a steel setup the diver has to overcome the compression of the suit and there may be nothing to ditch. The diver stays glued to the bottom.

The bottom line is that in any situation the diver needs to be able to remove enough weight to make an ascent possible. Or, with a dryuit, provide enough lift to get to the surface.

JoelW

 

[Lost Yooper]

I agree with what's been said about AL - wetsuits, ST - dry suits. I would like to add that some people choose to wear double AL's if they're doing a lot of rough water boat dives to help in getting around on the boat. Personally, I use steel tanks exclusively and love them.

FWIW, DIR has become SOP for some search and recovery teams around the country. In fact, in a team of six SAR divers there were three of us diving DIR -- one was the director. We were trying to get it SOP, but I left the area before it was implemented, so I don't know if they actually did it or not.

Take care.

Mike

 

[Rick L]

Hi I have 6 tanks all steel. 4-95s 2-72s
I like steel tanks better for boyancy and they last longer.
4 of my tanks are 25+ years old! I dont see many old aluminum tanks and have seen a lot fail hydros.
cyas rick

 

[turnerjd]

Taking rough ball-park figures, AND being neutral at the END of a dive (empty tank)

If you are diving with a 5mm suit, most people need somewhere between 12-18 Lbs of lead with a steel tank, and a little bit (about 4Lbs) more with an aluminium tank.

This becomes even worse with a drysuit, and many people use between 20 - 30 Lbs of lead with a drysuit and steel tank, and +4 for an aluminium.

So, Provided you are not using something thin and flimsy you have no problem using either type of tank.... Going with steel will just remove some of the weight from your weightbelt.

For what it's worth, I have steel tanks (5) and no problem with them whatsoever. In europe, Aluminium tanks are practically unheard of, Steel tanks rule! (due to cold water and thick neoprene suits)

Nothing against steel whatsoever from what you say you will be doing.

As for the S&R diving, if it is similar to the UK, you will not be using your own kit, unless it is entirely voluntary, when it starts getting organised by local government they start worrying about liability etc... and start supplying kit for you.

HTH

Jon T

 

[Lost Yooper]

I use a 10lb V-weight (or weight belt) with my double PST LP 95's, Halcyon SS BP (6lbs), 2mm crushed neoporene suit (supposedly neutral), 200g underwear, 3lbs on ankles weights(total), and that's it. Ten pounds isn't too bad, but that's for fresh water too.

Mike