What tank: AL80 or steel?

[eelnoraa]

I am new to diving, had about only 10 dives. I came across good deal on used AL80s, not sure if I should get one. Or should I just save more to go with steels??

The command consense seems to be AL80 -> bad. Steel ->good. Can someone explain to me why?

Thank you!

 

[Lone Frogman]

I have steel tanks made in 1943 still as good as new. Thats why I like steel. As for AL most dive shops won't fill them if they are older than 20 years. If you use steel you will need less weight on your weigh belt about 6 lbs. As far as steel 80's go, I do not like them because they are so short, the larger/ longer steel tanks trim out better for me. If your thinking steel I would look at steel 100's. . They are close to the size as an AL 80. If your a larger person you my think about a larger size. Without knowing your size and type of diving you plan to do, it would be hard to give you any more info.
WARNING BUY TANKS CAN BE HABIT FORMING (at least it has been for me).

 

[Colliam7]

I came across good deal on used AL80s, not sure if I should get one. Or should I just save more to go with steels?? ... The command consense seems to be AL80 -> bad. Steel ->good. Can someone explain to me why?

I am not certain that the consensus is quite that clear, but you will find a number of divers who favor steels over aluminum. The preference involves 1) buoyancy characteristics, 2) tank physical size, and 3) tank capacity, as well as the 4) available range of sizes. The AL tanks are more buoyant, which may be most noticeable at the end of a dive. The AL80 that starts out about 1.4 lbs negative when full ends up at 4.4 lbs positive when empty. Most divers will have to carry lead on their waist (or in BCD weight pockets) to compensate for that positive buoyancy. If you want more than 80 (or 77.3) cf of air, you can get an AL100, but that larger tank is still 3.5 lbs positive when empty, plus it is 8 inches in diameter, and weighs 40 lbs empty. So, it is a bigger heavier tank to lug around on land, that is more buoyant in the water. Steels, on the other hand, are generally more negatively buoyant, smaller in size (diameter and length) relative to capacity, and offer greater capacity. If you want 100cf of air, a HP100 is more negative (-1.0 when empty), smaller (7.25 inch diameter vs 8, and a little over 24 inches in length vs 26.2) compared to an AL100, while providing 100 cf. From there you can go to a variety of larger steel tank sizes, as your needs/wants and prefernces direct, in low pressure or high pressure models.

On the other hand, steel tanks are more expensive to purchase, are susceptible to rust, and the HP tanks may not be fillable to their working pressure in some areas, if fill operations don't have the optimal compressors and boosters.

In contrast, for smaller (pony, deco) bottles - 6cf to 40cf - AL tanks are generally preferred.

Even though there are reasons why divers may prefer steel over AL tanks, the AL80 is still the most common tank a) sold, b) provided in training, and c) available for rental, in the US. There is nothing wrong with an AL80, and if you can get a GOOD deal (=/< $80) on several used AL80s (in current hydro), you may want to seriously consider buying them. Don't buy just one tank, though. If you are buying, get at least two.

 

[Gilldiver]

A lot will depend on your body type, thermo protection (wet or dry suit) and what type of diving you want to do in the future. At 10 dives, you don't know what this is yet beyond the fact that you want to dive.

Lets start with "There is no "Right" tank, there are only some that are better then others in particular situations. At your stage, money may be a factor, look around for used tanks of any type but stay away from aluminum the are from 1989 or older because of a cracking problem some have and a huge amount of BS that surounds the issue. The hassel is just not worth it. You should be able to pick up old steel 72's for less then $50 and post 1990 aluminum 80's for $75-$100. Hp 100' steel tanks may run in the $75-150 range. With any used tank, try to make the sale conditional on passing a visual and hydro inspection.

Back in the 80's is was easy, you had steel 72's or aluminum 80's (there were some aluminum 100's and steel 100's came out in the late 80's. Now you have many choices, so here is a quote from a well known diver and instructor Joel Silverstine (Joel is 6'3" and around 230 and pretty solid built):

"Different steel cylinders have different bouyancy charachteristics. Some are rock heavy, some are light as a feather (figurately speaking) 7, 7.25, 8" cyliners all are different and displace different amounts of water. And each diver is different in displacement as well.... My favorite cylinder with a 5mm wet suit in fresh water is a Faber 95. With a 3mm a Faber 85. I can glide -- move to salt water and I will add a little weight to compensate for the salt water.

For doubles it gets a little more involved because of the weight of the bands and manifolds but still manageable.

I have found that Faber LP steel cylinders have a cleaner buoyancy swing than the X cylinders have. And when not overfilled they balance out very nicely with wet suits.

Aluminums tend to be a bit floaty and will require 8 lbs of neutralization balast to be added for just the cylinders. "

 

[herman]

If you can get a good deal on some AL's there is nothing wrong with them, yea you may have to wear a couple of extra pounds on your weight belt but lead is cheap compaired to the extra amount you will spend in steel tanks, esp if you are buying new. I would avoid pre 1990 tanks because of the problems Pete discribes above, there is more BS than facts going around about them but it's not worth arguing with an uninformed dive shop when you need a tank filled.
I for one can't (will not...is more correct- I can, just don't want to) dive steel tanks if I am in warm water, due to their buoyancy characteristics. A single steel 72 will overweight me by seveal pounds in fresh water and depending on the type of diving I am doing, that much overweighting is often unacceptable to me. In addition, a large part of my diving requires travel so I will not be taking my tanks along. While some places will rent large tanks or steels, the vast majority rent AL-80s so I might as well be using them at home as well. I rarely need anything larger than an 80 so I just rent larger tanks if I need them.
There is nothing wrong with AL tanks from a material standpoint. They are hard to beat from a cost standpoint and are 99% of what you will rent if you travel, making your weighting easier to keep up with. IMO, buy them, dive them and if you decide you want something else later, you can sell them and get most of your money back.

 

[Davidstealey3]

good points here, but no one mentions the neutral ( or negatively, not sure of the correct terminology ) alm tanks out there

 

[halocline]

If you're talking about the diving near the bay area, that's pretty cold water, meaning you will probably really appreciate the buoyancy characteristics of steel tanks. How much you're willing to spend for that is entirely up to you. If you post your weight needs, typical type of dive you're planning on using the tanks for, you might get more specific advice.

The other thing is, what is the deal you're talking about? Used AL80s have very low resale value, so it might not be as good as you think. To me, the best deal on tanks are (if you can find them) galvanized LP72s in good condition for $25-40. These work GREAT if you don't need more gas than they hold for the type of diving you want to do with them.

If you're looking for tanks to use with longer or deeper dives, it might be worth it to look for higher capacity tanks than either the LP72 or AL80.

 

[halocline]

good points here, but no one mentions the neutral ( or negatively, not sure of the correct terminology ) alm tanks out there

That's because the OP is talking about specific AL80s that he/she has found at a low price.

And, to be honest, most of the neutral AL tanks are just heavier, so what's the difference between using them and some extra lead on cambands? You're still carrying the weight on land. It's the weight/buoyancy/capacity ratio that makes steel tanks, especially the HP100s, so attractive.

 

[Davidstealey3]

That's because the OP is talking about specific AL80s that he/she has found at a low price.

And, to be honest, most of the neutral AL tanks are just heavier, so what's the difference between using them and some extra lead on cambands? You're still carrying the weight on land. It's the weight/buoyancy/capacity ratio that makes steel tanks, especially the HP100s, so attractive.

i know, i was just throwing it out there as another option

 

[Van Isle]

Just like most sport divers in the world use jacket BCs - whereas on scubaboard it looks like EVERYONE dives a BP/W - most sport divers around the world use aluminum tanks.

They work just fine. They are cheap. There are no concerns about getting a "full pressure" fill. Bought used, you lose no money if/when you sell them. They're likely what you trained with.

If, after a year of diving, you make up part of the 10% of certified divers who continue to dive, you might want to look in to getting a steel tank, which as a previous poster mentioned, can cost 3-4 times more to give you 3cu/ft more gas (for an 80) and take 4 lbs of lead off your belt. Whoopie.

VI