Double Aluminum 80's

[Mambo Dave]

I am not sure about weighted bands, but you might consider looking at compact 80's. They have a working pressure of 3300 psi, and are four pounds negatively boyant. I have a new set of doubles arriving shortly, and I am going this rought to compensate.

No sure if you were offering an idea based on my question, Cobalt, but mine was based around already owning AL80's. The tip that the bands would come in handy on vacation sites with rented dive tanks makes it all the more worthwhile. I guess my SAC sucks, or I suck, but getting additional bottom time while away without having to drag my HP steel tank around - or any tank - is good stuff.

 

[divad]

What are "compact 80's"?

 

[teknitroxdiver]

What are "compact 80's"?

http://divestore.scubacenters.com/M...Code=SD&Product_Code=AL80&Category_Code=Tanks

 

[Florabama]

What about the "neutral" AL 80s I'm seeing in catalogs? If they are really neutral, seems they would solve the "buoyant when empty" problem and be a little less expensive to double up than steel.

 

[Nemrod]

By the time you put a heavy double manifold and aluminum BP on standard aluminum doubles they are neutral or slightly negative at 500 psi, perfect for diving without a wet suit or with thin 3/2 suits.
Why fuss with heavy, rust prone and super expensive steel tanks in salt water? If you need a few more lbs negative go with the neutral 80s, these are negative with manifold and plate. N

 

[tlawler]

Sorry, didn't mean to offend you. I shouldn't have used the "quote-reply" as my post was meant as a general indictment of the narrow-minded "Steel Doubles are only to be used with Drysuit or Redundant Bladders - period" crowd. Your post addressed a fallacious solution to the "benefit" of AL doubles over steel.

What benefit would there be with AL doubles over steel? I don't see any. I guess I should have just said scrap the AL and go steel to remove any doubt of where I stood on the subject.

 

[CobaltDiver]

Compact 80's is another name for Neutral 80's. They are designed to be 4 lbs negative when the tanks are empty. They are wonderful in salt water. I dive the singles everyday at work.

 

[paulwall]

What benefit would there be with AL doubles over steel? I don't see any. I guess I should have just said scrap the AL and go steel to remove any doubt of where I stood on the subject.

We're on the same page, even if I don't come across that way. The "benefit" touted is
"in the event of a catastrophic failure of my BC Bladder, the additional bouyancy of (empty) AL 80's would assist me on my emergency ascent". Or stated differently, "I would have trouble swimming up the additional 6 lbs of steel tanks".

As for rust-prone heavy steels referenced by Nemrod:

By the time you put a heavy double manifold and aluminum BP on standard aluminum doubles they are neutral or slightly negative at 500 psi, perfect for diving without a wet suit or with thin 3/2 suits.
Why fuss with heavy, rust prone and super expensive steel tanks in salt water? If you need a few more lbs negative go with the neutral 80s, these are negative with manifold and plate. N

If you've got (and prefer the life expectancy) of steels, why spend any additional money for the AL doubles? I agree with nearly all of your statements, except

rust prone and super expensive steel tanks in salt water

Proper maintenance mitigates these "negatives" AL corrodes, too, you know! Also, Steel Doubles may not be the best choice with wetsuit in freshwater (although it is done regularly, with no problems) simply due to the less need for additional weight to get neutral.