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ScubaTodd77
July 13th, 2009, 06:45 PM
Pros/Cons of each? I seem to notice more experienced divers with steel so I thought I'd ask. I've never dove with a steel tank, but I was thinking about buying a second tank, and was wondering if I should get another Aluminum or try a steel tank, since they appear to hold more air.

diverdown78
July 13th, 2009, 06:54 PM
i have alum 80s...but i prefer steel...i think its personal pref

H2Andy
July 13th, 2009, 06:56 PM
well, steel tanks tend to be negatively bouyant at the end of the dive, so you need less weight

also they tend to be larger than 80cf ...

also, unlike many AL tanks, they don't tend to push your head down and your feet up towards the end of the dive

they are heavier, generally speaking; that's a possibly drawback

diverdown78
July 13th, 2009, 06:58 PM
well, steel tanks tend to be negatively bouyant at the end of the dive, so you need less weight

also they tend to be larger than 80cf ...

also, unlike many AL tanks, they don't tend to push your head down and your feet up towards the end of the dive

they are heavier, generally speaking; that's a possibly drawback

i have 5lbs staped to my alum 80s..it seems to do yhe trick

RMDiver
July 13th, 2009, 07:00 PM
I like steel. You don't end up being "too bouyant" at the end of your dive.

ptyx
July 13th, 2009, 07:21 PM
Assuming we're talking about a single tank, and AL80 vs HP100:

AL80 pros:

cheap
available everywhere
what you'll find for rental, so no need to adjust your gear when you travel
flat bottom, so can be used without boot if you object to boots


AL80 cons:

buoyant at the end of the dive, that means you need extra ballast (I'm at 19 with AL80, 12 with HP100)
relatively light even at the beginning of the dive, which makes sitting in the water less comfortable with a back inflation BC or BP/W.
actually 77cft, a lot less than a HP100
doesn't live as long as a steel tank
a bit too long physically for the average diver


HP100 pros:

always negative, so you need to carry less ballast (that's a cons if you dive tropical and don't need ballast at all with steel)
more air for approximately the same total tank weight
HP100 as a lot more gas than a AL80
diver weight distribution is balanced further back, which makes sitting in the water more comfortable
lasts forever (if cared for appropriately)
more compact than an AL80
failure modes are supposed to be less dangerous in steel than AL


HP100 cons:

expensive
round bottom - get a boot or be prepared to hold to it often
not what you'll rent - so you need to be prepared to adjust your gear when you travel


Tell me if I forgot anything, I'll add it to the list.

MaxBottomtime
July 13th, 2009, 07:48 PM
Scuba Cylinder Specifications from Tech Diving Limited - 928-855-9400 (http://www.tdl.divebiz.net/pub/tanks.html)

sohnje
July 13th, 2009, 08:04 PM
Get a steel 100, you will be very happy.

imwright1985
July 13th, 2009, 08:18 PM
i would just buy another AL 80, its better to have similar tanks to keep your weighting the same so you dont have to keep messing with it. Only way i would go steel is if i was looking to get more into tech type diving or making a switch to steel and would buy a 2nd steel in the near future and get rid of the al 80 or use it as a spare for when your getting a hydro done, have company, or may be doing 3 dives in a day

H2Andy
July 13th, 2009, 08:22 PM
i have 5lbs staped to my alum 80s..it seems to do yhe trick


that's cool ... that's not a heck of a lot of weight

i don't use any weight with a steel 108; bouyancy is extremely steady at the end of a dive

meesier42
July 13th, 2009, 08:24 PM
I would not agree with how long they last, I have recently seen quite a few steel tanks fail hydro, some at their first hydro (5years old). I have 1 AL that has 4-5 hyrdro's on it now. That's not to say steels is better or worse, but longevity should not really be a concern. If you find it worth buying your own tanks, then the useful life will mean that hydro/VIP cost, no different than the your regs are the real cost of ownership, not the up front cost. Most of my tanks have 200 dives on them each, meaning cost per dive on the purchase is nothing.

I believe there is a lot more to think about for tanks than just material. You need to look at how you want to use it. I have both tanks around, some I use some for beach dives in warm water, some with drysuits and cold water, some with nitrox and longer bottom times.

Al80's are a great tank is you plan to travel for a good portion of your diving, this allows you to become familiar with the buoyancy and trim of the tank that you will be renting with you get wherever you go. unless you are a smaller framed person (think <5'5" and <120#) there is no reason to even look at other AL's, if you are the small frame, then a AL63 is a great tank. its shorter than the AL80 and people this size generally have low enough air consumption that 63 cuft is plenty for most recreational dives. its shorter size will fit your torso better and you should have better trim and comfort (but again, the AL63 is not a commonly found rental tank)

Steel- if you dive nitrox, use a drysuit, or otherwise need a little more air, the HP100 or LP95 are awesome tanks. They are about the same weight and size as the AL80 but hold more air. When you travel, you will find that steel tanks are hard to find on rental. Steel, as already mentioned has some benefits in being nearly neutral or negatively bouyant at the end of the dive.

Now, if you are a tech diver, eh... this is a beginner forum, not aimed at you.

ScubaTodd77
July 13th, 2009, 08:42 PM
Thanks for the advice...I think I'll stick with the AL's just b/c of the travel issue. Diving dry is an interest, but that will have to wait for now. I wish I could afford to buy a set of both :(

imwright1985
July 13th, 2009, 09:03 PM
if you could buy 2 steels and sell your al you would be able to keep consistancy, I know some of the rentals include weight with tanks around here. Since i dive locally, AL's are cheap, and alot of my friends have AL so i can borrow one or 2 easily for extras i personally would lean to AL. If your not going to travel a whole lot, diving dry adds more bouyancy to you so a steel would be better to cut required weight amount. just think of the type of diving your going to be doing in the future and decide from that. I would just advise against having one AL and one steel so you arnt adding and taking away weight each dive For vacations you could always add weight since your rentals will more than likely be AL80's the whole time your on vacation and you wouldnt be switching weights other than when you get to your vacation spot and when you get back

equsnarnd
September 29th, 2009, 12:53 PM
I was told that in Europe there is a prohibition against Alum tanks because of research evidence that Aluminum Oxide can pass through the stages of a regulator and ends in your lungs: Aluminum consumption is one of the suspected causes of Alzheimerís. I havenít been able to verify that there is a prohibition. I'm skeptical and wondered if anyone on this list would know.

String
September 29th, 2009, 05:17 PM
I hate aluminium tanks.

They hold less gas than steel (typically 207 bar not 232). For the same size they're physically bigger and heavier than steel on land and in the water the things are positive (or near neutral) meaning you need to wear more lead on the tank just to sink the things. We have to use the evil 80 cubic foot things here. That works out at roughly 11.1 litres filled to 200 bar so 2220 litres of gas. My steel 12l at home is 2kg lighter, a few inches shorter, less diameter and holds about 2800 litres of gas so about 20% more in a neater, more comfortable and non buoyant package.

In the UK aluminium tanks are also more expensive than steel and more expensive to get tested. Id use Aluminium for stages but cant see a single thing in its favour vs steel for back gas.

AfterDark
September 29th, 2009, 07:41 PM
I've got 4 tanks 3 steel 72's and 1 AL80. Two of the steels were made during the 1960's one was made in the 70's, the AL80 was made in 1980. All are hydro'd and still in use.
To avoid having to mess with my weights I just dive a little heavy. I know it's some kind of modern day diving taboo but it works for me which is all I care about. It really does come down to personal preference. I like full tanks the best.:D

ZzzKing
September 29th, 2009, 09:57 PM
I have 2 AL80's and 2 HP100's. The AL80's are great for warm water diving in little to no exposure protection. I can dive them with a steel plate and no weight in the summer. They are also ideal for warm water sidemount diving. The 100's are great for everything else.

According to the chart linked above, the 80's weigh a little over 37 pounds when full and the 100's weigh about 40.5. So you're carrying 3.5 extra pounds worth of tank but about 5 pounds in additional weight to sink it at the end of the dive. So a total of 1.5 pounds extra for 23% less gas with the aluminum tanks. Of course the 100's cost nearly twice what the 80's cost.

knotical
September 30th, 2009, 08:55 AM
Tell me if I forgot anything, I'll add it to the list.Aluminum corrosion tends to be self-limiting.

DCBC
September 30th, 2009, 09:48 AM
It depends upon the application. I prefer steels for my primary and secondary systems, but normally use aluminum for my decompression bottles & for travelers.

It really depends upon the type of diving your doing and what you hope to do in the future. Many of my divers in their first few years dive using 80s. Their initial dives are less than 100 ft. with a second dive usually less than 60. The aluminum gives them everything they need.

More and more are starting to go with higher capacity steel singles as it gets more of the weight off the waist and provides a bit more air for a dry suit (where you live I doubt you have this requirement). As their diving experience increases, the Al bottles will be used in a similar way as I use mine; they wont go to waste. :-)

Doc Harry
September 30th, 2009, 04:45 PM
...and was wondering if I should get another Aluminum or try a steel tank, since they appear to hold more air...

Steel cylinders do not hold more air than aluminum clyinders.

Given two cylinders, one that contains a larger volume and one that contains a smaller volume, the cylinder that contains the largest volume will contain the largest volume regardless of the composition of the cylinder.

You should be looking at the buoyancy characteristics of the cylinders (full and empty, size, weight) and make your choice accordingly.

Also, if you are planning on the extra gas that comes with a high-pressure fill of a steel cylinder, make sure you can get 3,400 PSI fills in your area.

lefemme36
September 30th, 2009, 11:30 PM
If no one else has mentioned it, there is a difference in diameter as well for many steels vs. aluminum. I happen to dive both. If I started over and had the money I would NOT own any aluminum other than sling/stage/pony bottles. There are just too many benefits to steel. Steels rarely fail a hydro either.

RonFrank
September 30th, 2009, 11:43 PM
I would be diving steel except for two things:

1) Cost, they are a bit more expensive, or a lot! :D

2) Corrosion. They tend to corrode more easily vs. Alum.

The buoyancy characteristics are generally nice. More air in a smaller space, and the are negative at the end of a dive. So less weight on/in the belt/pockets.

I've been looking for some used steel for a while now. Steel does not appear to be popular in our area. If I lived in a better dive area, I'd definitely purchase some HP 95's, and pay the piper. Living here, I generally don't use 1500psi on a local dive, and not much more than 2000psi at the hole, so steel while nice, is not all that necessary for the diving we do locally.

N2DeepInAz
October 1st, 2009, 12:10 AM
Here's my two cents since we seem to have about the same amount of experience diving...

I started with 2 new AL80's cause they were cheap in comparison to two new steel tanks and I usually do 2 tank dives when I go out on my local dive boat. As I looked around and talked with other divers, I noticed many of them had steel tanks and wondered what the fuss was all about. So I ponied up and purchased a HP steel 100 tank to see the difference. The steel tank was a little shorter but much heavier of course, also it's a 100 cu ft vs the 80 cu ft in the AL tanks. So even though my SAC rate is pretty decent I was longing for more bottom time and deeper depths, the steel 100 allowed me to do that. I was able to push further and deeper with the steel 100 than the 80 simply because of the cu ft of air difference, but the compact size of the cylinder really made a difference as well.

I like the fact that I can carry less weight with the steel tank as well. The circumference of the two cylinders isn't that much different and I don't recall having to adjust my tank strap to use either type, they both fit fine without adjustments.

Now that being said, I'd love to complete the set of steels and get a second, but price is a bit restrictive to buy them in pairs right out of the gate or too closely together. They are also heavier as well so if you're doing a lot of shore diving then lugging steel tanks isn't going to be much fun.

Hope that helps for what it's worth. Happy & safe diving!

Carlos Danger
October 1st, 2009, 12:58 AM
Perhaps the material isn't the question.

Steel is expensive; then again, the best always usually costs more. On the other hand, AL has always been the standard offering on every ocean dive trip that I've been fortunate enough to go on. The reasons for-or-against are both valid and varied.

Generally speaking, if you have a specific dive application that you're looking to optimize, then steel is tough to beat. Steel's combination of variety, size, strength, capacity, and buoyancy characteristics are unmatched. If you want to perfect your skills against the equipment profile you'll more than likely see on your next vacation, then training with AL may be the way to go.

Obviously there can be other considerations. As with many decisions in scuba, the best solutions may be based around an examination of the expected environmental factors vs. equipment availability, performance, and costs.

In other words, figure-out what you need and why, then choose from a short-list of avialable quality equipment options that best meets your needs.

pittyyofool
October 1st, 2009, 05:23 AM
My dad can beat up your dad!

:argument: :deadhorse:


I would not agree with how long they last, I have recently seen quite a few steel tanks fail hydro, some at their first hydro (5years old). I have 1 AL that has 4-5 hyrdro's on it now. That's not to say steels is better or worse, but longevity should not really be a concern.
hummm... I have steel tanks from the 1950's (9 hydro's) , 60's, 70's, and 80's and they all pass hydro's with no prob. I have never had a steel tank fail, wile all 3 of my aluminum's have failed, and they were way newer than the steel. I have heard that the "new" HP steel tanks fail more often.



Al80's are a great tank is you plan to travel for a good portion of your diving, this allows you to become familiar with the buoyancy and trim of the tank that you will be renting with you get wherever you go.
you get use to it, just add 3-4 lbs of lead when using aluminum compared to a 72


Thanks for the advice...I think I'll stick with the AL's just b/c of the travel issue. Diving dry is an interest, but that will have to wait for now. I wish I could afford to buy a set of both :(
What travel Issue?


i would just buy another AL 80, its better to have similar tanks to keep your weighting the same so you dont have to keep messing with it. Only way i would go steel is if i was looking to get more into tech type diving or making a switch to steel and would buy a 2nd steel in the near future and get rid of the al 80 or use it as a spare for when your getting a hydro done, have company, or may be doing 3 dives in a day
Switching tanks is not a big deal, you learn how much lead to add or subtract for each tank, I have 12 tanks with 5 different buoyancy's. It doesn't get confusing till you have 5 wetsuit configurations depending on temperature.

I will most likely never buy another AL tank, I just don't like them as much and they don't last 55+ years

I vote for you getting a steel used 72 and never looking back. An LP 95 is a good big tank to.

And search your local craigslist, there is always good stuff on it.

something to read
How to Select a SCUBA Tank - Dive Gear Express (http://www.divegearexpress.com/library/tanks.shtml)

Butch103
October 1st, 2009, 07:38 AM
Huh??......You can get steels which hold the same volume of air as steels.....Try them and see what you like. Heavier steels may make you roll onto your back ...If you get a larger tank...

cks44diver
October 6th, 2009, 08:56 PM
if you have al 80 already, buy another one.
this way you dont have to adjust your weight between dives.
i dive both depending on situation.
if i am with students i dive al 80, if fun diving i use steels.

supbihatches
October 6th, 2009, 10:01 PM
I recently sold my aluminum tanks and got two steels. I love them, they hold more air for the size and keep the weights out of my pockets since they generally stay more negative. Plus DIN is the way to go.

mbwilliamn
October 6th, 2009, 10:37 PM
Assuming we're talking about a single tank, and AL80 vs HP100:

AL80 pros:

cheap
available everywhere
what you'll find for rental, so no need to adjust your gear when you travel
flat bottom, so can be used without boot if you object to boots


AL80 cons:

buoyant at the end of the dive, that means you need extra ballast (I'm at 19 with AL80, 12 with HP100)
relatively light even at the beginning of the dive, which makes sitting in the water less comfortable with a back inflation BC or BP/W.
actually 77cft, a lot less than a HP100
doesn't live as long as a steel tank
a bit too long physically for the average diver


HP100 pros:

always negative, so you need to carry less ballast (that's a cons if you dive tropical and don't need ballast at all with steel)
more air for approximately the same total tank weight
HP100 as a lot more gas than a AL80
diver weight distribution is balanced further back, which makes sitting in the water more comfortable
lasts forever (if cared for appropriately)
more compact than an AL80
failure modes are supposed to be less dangerous in steel than AL


HP100 cons:

expensive
round bottom - get a boot or be prepared to hold to it often
not what you'll rent - so you need to be prepared to adjust your gear when you travel


Tell me if I forgot anything, I'll add it to the list.
Nice summary! Agree with all (except longevity of ALs). Bottom line for me is I use the AL 80s. Main reasons are: lower cost (4 divers in the family!), I don't need the extra air (well, except for occasionally lobstering and I carry a pony), I only use 2lbs of wt with AL tanks most of the year, so steels overweigh me a lot (+6lbs over AL).

Oh, and get the ProDIN valves...Its a DIN with an insert that makes it a yoke. Great flexibility for little cost.

highlandfarmwv
October 7th, 2009, 01:32 AM
I love my steel 80 HP. You don't have to get a 100 if you go steel. the steel 80 is about the size of an aluminun 63

Vlane
October 7th, 2009, 01:47 AM
Some of you mentioned that the weight distribution is different with steel. With my AL80 my feet tend to sink if I don't use trim pockets. What kind of effect would a HP100 have on my trim?

mbwilliamn
October 7th, 2009, 01:43 PM
Some of you mentioned that the weight distribution is different with steel. With my AL80 my feet tend to sink if I don't use trim pockets. What kind of effect would a HP100 have on my trim?
It really depends on your setup. I wear integrated wts (2lbs) to neutralize my rig and a wt belt to offset my thermal protection. If I'm using a Shorty and John or 7 mil, I drop 6 lbs from my belt which shifts the CG toward my head a little. If I'm diving a skin, I can only drop the integrated wts (Don't need a belt with the skin), so my overall CG shifts down...in this case I usually throw a 1lb ankle wt around the tank valve to shift my trim back up. If you wear your gear higher, lower or have one with more or less built in buoyancy your results will be different.

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