why not doubles on AL?

[ew1usnr]

When I said "roughly neutral for much of the dive", I meant that at the beginning of the dive I am firmly negative with no additional weight. The tanks begin to become positive at the end of the dive. If they go from negative to positive, that means that they were indeed neutral at the midpoint of the dive.

 

[FIXXERVI6]

The neutral 80 is neutral when it is empty, and more negative than a standard when full, no one tried to sell me on it as far as it being neutral all the time, it changes the same amount as a standard 80 (give or take .02 lbs or something like that). The differance is with a neutral, I need little to no weight around my waist, I like it better because the more weight I Have around my waist , I feel "clumsier" and keep having to adjust the weights to stay level in the water because I have no butt and the belt moves around.

 

[mrducks]

don't waste your time with double al tanks or al tanks at all 4 that matter.
use lp steel( faber 121's or 135's) and blow them 2 the level u need.
al tanks float and have very little memory!

 

[roakey]

mrducks once bubbled...
don't waste your time with double al tanks or al tanks at all 4 that matter.

I take it you don't dive wet in Akumal very much or use stages?

Given the right equipment combination, ALs are great.

Roak

 

[mrducks]

have not been to yucatan cave diving for ten years

you've got me on this one....30 feet deep on a major push in the third world i would consider al the best choice i suppose.
otherwise dump um 4 scrap.

 

[Mikel]

From your post thought of a question. My bc has two cam bands. with one al 80 I only need 2 lbs. Can I just put that on the top cam band (I want my feet up a little higher anyway)? If I switch to double al80's, about how much if any extra weight will I need and can that also go on the bands. And going from a skin to a 3 mil, about how much will I need for the single and doubles? Would want as much as is safe on the top cam band and balance can go on weight belt. Advice please!!!
Mike

roakey once bubbled...

No!

A common misconception. Air weighs about 1 pound for every 13 CF. It doesn't matter if the cylinder is steel, AL or wood, if you stuff, say, 80 CF of air in it, it'll be 6 pounds more negative when full than when empty.

I really hate the phrase "neutral 80" -- it's typical marketing department BS to make you think the wrong thing. A normal AL80 will swing about 6 pounds from full to empty, as will a Steel 80, as will a "Neutral" 80.

It's just that the neutral 80 is more negative when empty than a “normal” AL80 (like 0 versus +3), which can be accomplished far more cheaply by strapping a three pound weight on your cam band...

I hear this from dive shops all the time: “An AL doesn’t change buoyancy as much as a steel” I don’t know how physics works where they come from, but in this universe a cylinder will become 1 pound more negative for every 13 CF of air you pump in it, no matter what.

Roak

 

[8buck]

Hey I have five al80's and was wanting yall's yea and nays about double al80's and do cavers dive with them?????? am gonna set up a set and someone i was talking to seem to think i need steel??? i have read many many post on yeas for al80's

 

[Don Burke]

8buck once bubbled... Hey I have five al80's and was wanting yall's yea and nays about double al80's and do cavers dive with them?????? am gonna set up a set and someone i was talking to seem to think i need steel??? i have read many many post on yeas for al80's

I have a set of double AL80s.

They are pretty good in the ocean with a wetsuit and a bit on the hefty side with a drysuit.

I dive aluminum doubles wet and steel doubles dry. I'm in the process of figuring out how to safely dive the steel doubles with my wetsuit.

 

[8buck]

And the real issue on din vs yolk

 

[Don Burke]

8buck once bubbled... And the real issue on din vs yolk

Not for me. DIN is a much better way to go with double tanks.