Anyone dive double AL 53's?

[Nemrod]

Oh, yeah, the Catalinas, they are a bit heavier if I recall and somewhat more negative than the Luxfer product. That is why I went with Luxfer 50s. I have never had any Catalina 53s but aren't they a 7.25 inch tank, the Luxfer 50 is a 6.9 inch tank. Never had good luck with Catalina tanks so I don't really think about them much, they all seem nose heavy, maybe I am wrong there.

When people say steel has better bouyancy charateristics than aluminum, mostly true, but what if you are diving in just a rash guard in 80 degree water or sans BC? Then a negative steel tank is not so great.

Steel 72s are your best bet, they are 6.9 inches also so you can swap them with the same bands you use with a Luxfer 50s. N

 

[BobbyT22]

Thanks Jim and Nemrod. Will accelerate my efforts to find some 72's. Yes the Catalina's 53's are 7.25 inches, and I think I have decided against them, too short and stubby.

If I find the Faber 45's used will certainly be back looking for help putting them together. Man, they look like a sweet setup.

Rob

 

[jimyoungdd]

I dive with Steel 100's. When I put both tanks in the water they are just a little
negative. So your -12 lbs neg does not add up. Add on top of this you have an
AL pony, so I don't get your big time buoyancy issue. Don't have the buoyancy info on steel vs Al handy, so I can't give you the stats.

However, the questions really seems to be should you go to small doubles.
Any doubles will make you less stream-lined and make you work harder and use
more air. The main reason for doubles is more air for deeper and or longer dives.
Not doing non-deco 30' to 80' quarry dives. And say you stated you don't need the
extra air your steel tank gives you.
The way I read it your diving needs seems to led it's self to an Aluminum tank
and use your pony for redundancy. Or maybe go to an H-value set up.
2 to 3 lbs should be plenty to balance your rig. May consider hanging your pony
under your arm with clips so if needed you can hand off your pony to someone who
may needed it. Setting it up this way you will not need to use anything or maybe a
pound to set trim.
Jim[-][/-]

 

[WD8CDH]

Skinny small doubles are easier to dive with than singles. It's the short, fat doubles (like double al 50's)that you want to stay away from usually. Oncy you try a set of skinny doubles, like the 5.5" diameter 45's and 50's, you will never want to dive a single. I personally dive double 40s, triple 40s, triple 35's and quad 20s whenever I am not diving a rebreather.

 

[digital_steve]

interesting thread
i'm about to get a set of faber 7L 300bar cylinders (i think they equate to steel 70-72 cuft tanks) and they are long and skinny.
i'll be using them for redundancy in solo and a bit of extra gas for shallower dives.
people i know that use them rave about them
i'm not sure i'd bother with the 45/55cuft fabers (232bar 7L here) as you'd have to be damn quick to shut them down to save gas.

 

[WD8CDH]

Personally, I would configure the 5.5" diameter 45/55 cf tanks as triples with 2 tanks manifolded and the third independant.