Can someone run down which tanks work best for DIR style stage bottles?

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beanojones

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Can someone run down which brand tanks work best for DIR style stage bottles?

Because of the way DIR runs stage bottles it seems that buoyancy matters in the 80's and 40's used. Which brand and which one is the DIR standard for stages?

And does anyone have any good video or pictures of lots of stages being used to see how they ride in use?
 
Bear in mind that I am not a "DIR Rep" or what-have-you, but this is my understanding.

Luxfer AL80s for stages, (and sometimes deco) and AL40s for deco.

Catalinas can be used, but the Catalina 80s are slightly heavier in the water, (only slightly), but it makes them ride terribly. I think the Luxfers are more butt-light than the Catalinas, and ride better when full, but as they get breathed down, the Catalinas start to ride better. (I did a back-to-back test with Catalina and Luxfer 80s, rigged up identical. The Luxfer rode better the whole time, but past 2500psi or so, the Catalina wasn't bad and got better the emptier it got.)

My personal opinion, the Catalinas make better backgas tanks because the butt of the tank is reportedly a bit heavier, (helps offset the weight of the tank shoulders and the manifold and regulators), so it balances and trims out better. (On me at least).

Problem for stages is that Catalinas are what's available new, (I like new), so unless you look used and avoid the TONS of older Luxfers made of the crispy 6351 alloy, (all Luxfers made after 1988 are OK, avoid earlier ones), you're stuck with Catalinas.

Don't know the difference between the AL40s, but enough people comment on them to make it sound like there is a difference. I work in a shop and can get Catalina AL40s for cost all day long, but I'm holding out for Luxfers if I can find some used at a good price. Trouble is, often times, people know what's up, so used Luxfer AL40s command "new" prices.

That's my brief experience.
 
Luxfer AL80s for stages, Luxfer AL40's for deco, then 80s if you need more than that. Beyond that, LP85/95/108s seem to be popular for extremely long decompression schedules during cave exploration.
 
Does Luxfer only make one AL80 and one AL40? There seems to be a whole mess of 80's to choose from compact, neutral, etc. etc.

(To be honest, as much as anything, I want to get the right 80 to do some monkey diving for starters. Then move it to multi stage stuff for fun and practice.)
 
Does Luxfer only make one AL80 and one AL40? There seems to be a whole mess of 80's to choose from compact, neutral, etc. etc.

(To be honest, as much as anything, I want to get the right 80 to do some monkey diving for starters. Then move it to multi stage stuff for fun and practice.)
Just the normal AL80...you don't want the neutral ones.
 
Can you really tell a difference with a catalina vs Luxfer AL40 ???
I can understand for AL80, but for 40cf, it is harder to believe. Even the reg you'd use there could offset the buoyancy difference... I'd be interested to know though. Price delta is not that big (10-15$), but if this the consensus and this +1lbs difference for the luxfer makes it easier, why not a tiny bit of help to begin with...
 
So I take it is the buoyancy of those tanks that allows them to be trailed behind the diver all on one side?

The neutral 80s might as well be steel lp85s they are low hanging pigs. You'll either be overweighted or using the stage as part of your weighing which we don't do. Being able to ditch all stages and not get positive is important.
 
Can you really tell a difference with a catalina vs Luxfer AL40 ???
I can understand for AL80, but for 40cf, it is harder to believe. Even the reg you'd use there could offset the buoyancy difference... I'd be interested to know though. Price delta is not that big (10-15$), but if this the consensus and this +1lbs difference for the luxfer makes it easier, why not a tiny bit of help to begin with...

Its not that big a deal. The Luxfer, Catalina and Hymark 40s are all close enough.
 
https://www.shearwater.com/products/perdix-ai/
http://cavediveflorida.com/Rum_House.htm

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