AL100s? Thumbs Up or Thumbs Down?

[Charlie99]

Another point that nobody has mentioned yet is the diameter. AL100 is 8" diameter, HP100 is 7.25" diameter. Less drag.

One minor downside of HP steel is the 3500psi fill pressure vs 3300psi for the aluminum. If you get a short 3000psi fill, the AL will have a bit more air.

Contrary to what some seem to think, air weighs the same whether it's in a steel tank or aluminum tank, so the buoyancy swing from full to empty will be the same. What does differ is the empty buoyancy, and the initial full weight out of the water.

When comparing a Luxfer 100 and a PST 100 you will see that empty buoyancy of Luxfer AL100 is 3 pounds positive, while the PST100 is -1.3. That means you can carry 4 pounds less lead with the steel tank. The steel tank also weighs (in air) only 34# vs the AL100's 41# --- that's another 7 pounds less weight to carry around the boat or down to the beach.

Charlie

p.s. there are several website with compilations of scuba cylinder specifications.

 

[DA Aquamaster]

Charlie nailed the major downside - AL 100's are heavy. A PST HP 100 is 7 lbs lighter. A PST E7-100 is 2 lbs lighter still and is the same empty weight and diameter as an AL80 but it is -1.3 lbs bouyant when empty and is 2 inches shorter.

On the other hand, an AL 100 is a relative bargain price wise and unlike E7-100's you can actually find one for sale.

 

[dilligaf368]

Go Steel, I got rid of the last Aluminum tank, Thank God! I have the origional steel tanks from the late '60's and they are still going strong. They are a little small (72's) and I have stepped up to a few steel 100's and 120's. The HP Steel is the way to go. Same weight as the LP's but larger dia. The next set will be HP 120's. Thanks to "Uncle" pugs comments,,,I can breath just as fast or slow as I want to! B--------

 

[KOMPRESSOR]

I can't figure how you guys even manage to calculate your lead weight with those alum tanks. If you dive in warm waters with 3 mil wet suit, yeah sure. But with 7 mils wet or even drysuits, how do you do this without going to the surface like a submarine at the security stop?

In Europe, northern at least, alum main tanks aren't used by anyone. You'd be surprised how much trouble you'd get even to get an airfill on one! (Some consider them a good substitute for F16 bombs...)

Steel it is, wether its 200, 232 or 300 BAR...

 

[Charlie99]

I can't figure how you guys even manage to calculate your lead weight with those alum tanks. If you dive in warm waters with 3 mil wet suit, yeah sure. But with 7 mils wet or even drysuits, how do you do this without going to the surface like a submarine at the security stop?

Jeez. Yet another diver that doesn't understand basics.

Air is air. If you've breathed down 100 cubic feet of gas you are going to be about 8 pounds lighter. IT DOESN'T MATTER WHETHER THE AIR WAS INSIDE A STEEL OR AN ALUMINUM CONTAINER.

You will need to wear some addtional lead to get your buoyancy right with the AL100, but the CHANGE in buoyancy during the dive is exactly the same.

If you "can't figure how you guys even manage to calculate your lead weight with those alum tanks", you should go find an instructor and do a basic review.

 

[JeffG]

Jeez. Yet another diver that doesn't understand basics.

Air is air. If you've breathed down 100 cubic feet of gas you are going to be about 8 pounds lighter. IT DOESN'T MATTER WHETHER THE AIR WAS INSIDE A STEEL OR AN ALUMINUM CONTAINER.

You will need to wear some addtional lead to get your buoyancy right with the AL100, but the CHANGE in buoyancy during the dive is exactly the same.

If you "can't figure how you guys even manage to calculate your lead weight with those alum tanks", you should go find an instructor and do a basic review.

Your fighting an uphill battle....these are the same people that use 100lb wings because the tanks weight 50lbs each.

 

[matt_unique]

Another point that nobody has mentioned yet is the diameter. AL100 is 8" diameter, HP100 is 7.25" diameter. Less drag.

The tiny drag difference is irrelevant. A diver using a 7.25" tank will not burn more or less air if diving with an 8" tank.

--Matt

 

[jamiep3]

Seaquest 7/6/5 Steamer
7mm Hood
Luxffer AL 100
Aqualung Malibu RDS B/C
18lb. of lead
Fresh Water

It can be done.

I know what Luxffer's tables say about tank boyancy, but I actually need 2lb. less than with my Catalina AL80. Other than that, no real difference once I'm in the water

 

[KOMPRESSOR]

Soooo funny people in here.... I see I've written myself into an idiot in some people's eyes here. So be it, but a little politeness isn't to much to ask for. IS IT? You try making yourself understood in french or any other language...

(I bet you don't know a second language, but now I'm beeing rude so I'll stop it!)

Of course I know the weight difference is the same, whether you use air from steel or alum tanks. My point was rather that you have to use all that extra lead to your alum tanks compared to what you would have when using a steel tank with the same gear config, to at all being able to make a safe stop at 5 meters. (Do you know what one meter is?...)

So why are you using alum tanks? If you dive with 5-7 mil wetsuits, semis or drysuits, sell the darn alum tanks and get some REAL scuba tanks.
-And then you can sell off some lead as well.

Just my strong opinion. You may disagree if you like.


EDIT: Oh, my wing has 18 Kilos lift. -That's 40 Ibs. And it's Made in the USA, but that doesn't make it any better. Of course if you use alum tanks, you have a good lifting ballon in that as well when it's empty!

 

[MASS-Diver]

So why are you using alum tanks? If you dive with 5-7 mil wetsuits, semis or drysuits, sell the darn alum tanks and get some REAL scuba tanks. QUOTE]

I dive double al80s w/ a 6lbs V-weigth w/ my Drysuit. Al tanks are cheap, I love how they ride, and I get plenty of bottom time with them. Sorry you don't consider them REAL tanks.