steel or alu?

[Xaryo]

Hi!

I'm looking to buying cylinders, but I don't know what to choose between steel or aluminium. Since I'm not very high (5'3") I think I would go for steel 'cause for the same volume, these cylinders are shorter than alu. Or for the same lenght steel ones have a bigger volume.

Any ideas?

 

[Divers Direct]

Buying tanks should be determined on how often you dive and how fast you go through air. Steel is thinner than aluminum which allows for more air capacity. With high pressure steels you can get up to 3442psi. You use less weight with steel tanks so if you want to drop some weight then go with steel. If you don't blow through air quickly or don't care about dropping a couple lbs of weight in your belt then go with the aluminum. It's more cost effective. Theres always the big debate on which one is of better quality and will last longer. That depends on the diver taking care of the tank. If you take care of your tank either one will last you a long time.

 

[Aspendiver]

With your size, you probably don't use much air- I bet an aluminum 63 is all you need. Or maybe that worthington (XS Scuba) hp 80 - it's less than 20 inches long. There are disadvatages to using higher pressure- supposedly it accelerates corrosion. I've got a Worthington LP 85, shorter than an alu 80, neutral at the end of the dive, and about 10% more air (83 cubic feet vs. 77).

 

[The Chad]

Also it depends on if your going to continue your education. Or just do vacation diving. Tons of choices either way LP steel heavy, HP steel sometimes tough getting good fills.

 

[BKP]

I own both (including 'compact' al80s). My one and only complaint about steel (my HP100), is what Chad referred to: tough getting good fills at 3442psi. Even if they do give you a full fill, seems it's more often a hot-fill, and cools down to below 3000, and most won't bother to top it off.
Even then, the HP100 has a solid 89cuft. at 3000psi (and is still lighter, smaller, and more negative than aluminum).
That's my *only* complaint. Everything else for the steel is upside (as long as you can afford it).

 

[dannobee]

Although the vast majority of my tanks are steel because of the weight benefit, there might be a reason to have aluminum. When I was diving in Florida, I brought my SS backplate and required no additional weight with an AL80 and a 3mm wetsuit. With a steel tank, I would have been severely overweighted.

If your weighting is such that you have plenty of weight on your belt (or in your pouches if integrated), you'd benefit from having steel tanks. You could reduce the overall amount of weight you're carrying around.

There are many more options regarding capacity with steel tanks. Aluminum tanks generally come in one very standard size (AL80), and a couple of oddball sizes (63 cu ft, 100 cu ft, then a few pony sizes), but *generally* one standard pressure. Steel tanks can vary greatly in capacity and have several different pressures (2250, 2400, 3000, 3180, 3442, 3500, 4300, then some even have "+" ratings).

Getting full fills on the higher pressure tanks (either steel or the 3300psi Aluminum tanks) are such a big problem that I bought my own compressor. I got really tired of paying for a full fill and walking out with 3-400 psi less than the rated pressure. If you do most of your diving off of a boat that has a compressor, it will be even more of a problem.

FWIW

 

[Aspendiver]

BTW, I think the alu 63 is only a lb. or two positive when empty.

 

[ToddK]

I think if you dive cold water, steel tanks are a good way to go, just to get some weight off of your weight belt.

 

[Jimmer]

Being Canadian and diving cold water, I would encourage the steels. For your height, maybe LP85's or HP80's. See if you can rent or borrow a few different options and see how you like them. If you're ever down in my neck of the woods near Lake Erie, I can get an HP80 for you to try.

Jim