AL100s? Thumbs Up or Thumbs Down?

scubastew · Mar 7, 2005

Does anyone dive Aluminum 100cuft Tanks (low pressure)? What are the pros and cons to diving with the larger cubic feet? What gear changes did you have to make to accomidate the AL100? Would the bottom time be comparable to a high pressure steel 100? Thoughts??

The biggest "pro" I can think of is increased bottom time but for downsides I assume there's the added bouyancy (when empty) and lugging a bigger tank around the beach/boat?

thanks for the feedback!! I appreciate the board and the input from all of you.

again, thanks folks

~stu

MSilvia · Mar 7, 2005

Buy steel Stu. I wish I had, and will next time.

jamiep3 · Mar 7, 2005

I've got two AL 100s from Luxfer.

The upside is the extra air and I can use 2# less weight than with an AL 80.

The down side is that for the same size and weight I could have a PST E8 130. The Aluminum tank was a bargin when I bought it, but I'm planning to switch to PST E7 100's this summer.

Also my AL100s are 3300psi tanks.

DiveAngry · Mar 7, 2005

Get Steels!!!

Don't waste your money on alum high capacity cylinders. They are a little heavier when filled to 3300psi, but are much more buoyant than Alum 80's when on the empty side.

I'm surprised jamiep3 was able to remove weight from his weight belt (or BCD). True the 100 Alums are a little more negative when they are filled (more air = more weight), but because of the larger tank size (more volume) they are MUCH more buoyant when they drop to 500psi. I think is it like 5 or 6 pounds positive. I believe the tanks start about 3 pounds negative when fill at 3300psi.

So during the course of your dive, you'll become about 8 pounds more buoyant, than when you started - Good Luck on your nice slow ascent!!!

True Alum 100's are much cheaper.... But HP steels have much better buoyancy characterists.

Big Picture - You'll carry around alot less weight on every dive you do!!

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Dive Angry

JeffG · Mar 7, 2005

DiveAngry:
So during the course of your dive, you'll become about 8 pounds more buoyant, than when you started - Good Luck on your nice slow ascent!!!

No different than any other 100 cf tank...LP...HP...Steel...Plastic

divedeepnj · Mar 7, 2005

I dive with an al 100 on ocassion. You just have to ask yourself if it is worth the extra expense to buy steel. Keep in mind that you'll (hopefully) never drain it and have a lot of extra buoyancy. If you keep it under 130fsw you hit deco time before you are anywhere near being out of air. It's just extra gas in case you need it. Just weigh your options.

Firefyter · Mar 7, 2005

DiveAngry:
Get Steels!!!

Don't waste your money on alum high capacity cylinders. They are a little heavier when filled to 3300psi, but are much more buoyant than Alum 80's when on the empty side.

I'm surprised jamiep3 was able to remove weight from his weight belt (or BCD). True the 100 Alums are a little more negative when they are filled (more air = more weight), but because of the larger tank size (more volume) they are MUCH more buoyant when they drop to 500psi. I think is it like 5 or 6 pounds positive. I believe the tanks start about 3 pounds negative when fill at 3300psi.

So during the course of your dive, you'll become about 8 pounds more buoyant, than when you started - Good Luck on your nice slow ascent!!!

----
Dive Angry

This is kind of misleading. The truth is a Luxfer AL80 is -1.40 lbs full, and +4.40 lbs when empty. An AL100 is -4.35 full, and +3.06 empty. The increased swing is ONLY because of the increased amount of gas, eg. 100cu. ft. vs. 80 cu. ft. The AL100 is still a heavier tank than the AL80, and is still more negative than the AL80. This swing is going to occur regardless of the type of tank used, as JeffG pointed out, simply because of the amount of gas.
That aside, I use an AL100, and love it. I can make as slow an ascent as I want to, plus it allows me to keep up with the women using the 72 cu. ft. tanks.....lol

jfoutz · Mar 7, 2005

If Im traveling and the dive operator has AL100s, Ill rent them rather than 80s. Generally this means Im staying shallow or Im going to do some light deco. (No reason to waste the gas). They do have pretty crappy buoyancy characteristics however, and I wouldnt buy an AL 100. Ive got two steel HP 130s on order and I wish I could afford two more.

MASS-Diver · Mar 7, 2005

scubastew:
Does anyone dive Aluminum 100cuft Tanks (low pressure)? What are the pros and cons to diving with the larger cubic feet? What gear changes did you have to make to accomidate the AL100? Would the bottom time be comparable to a high pressure steel 100? Thoughts??

The biggest "pro" I can think of is increased bottom time but for downsides I assume there's the added bouyancy (when empty) and lugging a bigger tank around the beach/boat?

thanks for the feedback!! I appreciate the board and the input from all of you.

again, thanks folks

~stu

Stu, the al100 is a HUGE tank that rides like crap. I dive double al80s, so it's not that I have problem with al tanks - I just think that one is a monster and we need to keep out stuff squared away down on the South Shore - no 10' tall tanks

Also, if you by al - do not get painted. PM me what dive shop is trying to see you an al100

theskull · Mar 7, 2005

One of my buddies dives the Al100 and loves it. He is tall, though.

100 cu ft is 100 cu ft. A high pressure 100 will be a little more compact, though.

Buy what you want to buy and dive what you want to dive. If possible, dive it a couple times first to see how well YOU like diving with it. A tank can always be resold for near purchase price to someone, so don't fret over the decision.

I dive with aluminum and with steel tanks. As small as Al63 and as large as a Steel LP 131. All have their place.

theskull

AL100s? Thumbs Up or Thumbs Down?

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