Al 30 or Al 40

[RTee]

Just have the regs O₂ serviced.

They come out of the box O2 ready (80% @ 3400 and 100% @ 2400). What I wanted to know is what else needed to be done so one could be used for 100% @ 3000psi...are we talking parts, cleaning, etc

 

[Colliam7]

I am in the market for a bottle to sling, and use as a RAS during wreck diving in lake Huron. Also I will be using it as a stage bottle in the future. So the question is, should I purchase a al 30 or a al 40.

If I was buying a new bottle, like most respondents I would go with a 40 - more gas, easy to sling, greater span of utility as a deco bottle, etc. I have (2) AL40s and (2) AL30s (all Luxfers), and like both sizes. I happened to buy the 30s used, along with a couple of sets of doubles, so they were not an 'intentional' purchase. Nonetheless, I use them.

Still debating LP vs HP for the 40 though...

LP40 vs HP40???

For those using 40 HP and HOG, are you using them for 100 O2 and if so...filled to 3000 or 2400 psi.

I usually use my AL40s (or 30s) with 100% O2. (But, I usually only use 50% and 100% as deco gases, so I am not saying that they couldn't be used with an 80% mixture, for example). I fill them to 3000, which requires boosting. Some fill stations (e.g. 40 Fathom) will not boost 100% O2, in which case I go with 2400. On occassion, I have filled a 30 with whatever I am using as my backgas mix, and taken it along as a third slung bottle. I don't mind using a 30, instead of a 40, as my 100% bottle (when I can fill it to 3000) if the run times and projected gas consumption allow.

 

[AndrewA]

I use both 30s and 40s but the 40s are much more versatile and as others have said have great buoyancy characteristics.

 

[Buoyant1]

definitely a 40! I don't even know it's there when I'm diving, but I'm glad it is!

The rationale someone once gave me was IF you decide to start taking tech courses, a 40 is the standard for deco bottles.


40 all the way!

 

[MarineResearch]

Bigger is better.

Go with an AL40. On a recent trip the AL40 barely met my planned deco requirements for two dives. I have a second AL40 for an upcoming three dive trip to avoid having to limit the duration of my dives. Maybe I'm just numb, but I don't even feel the AL40 hanging at my side when diving.

 

[50Fathom]

The other question seems to be where to get Luxfer 40s? Research here indicates that Catalina cylinders have absolutely terrible buoyancy, while Luxfers were handed down from The Almighty himself.

However, I cannot find Luxfers available ANYWHERE. I work in a shop and can get Catalinas all day long, but apparently they are to be avoided like the plague.

Is it REALLY that bad, or is it overstated? Would Catalina 40s work OK as deco bottles?

 

[Medicdiver0125]

That would be the next question, luxfer or Catalina. I have seen the both on LP for good prices.

 

[MarineResearch]

The other question seems to be where to get Luxfer 40s? Research here indicates that Catalina cylinders have absolutely terrible buoyancy, while Luxfers were handed down from The Almighty himself.

However, I cannot find Luxfers available ANYWHERE. I work in a shop and can get Catalinas all day long, but apparently they are to be avoided like the plague.

Is it REALLY that bad, or is it overstated? Would Catalina 40s work OK as deco bottles?

Dive Gear Express

XSS-AL-40LUX Luxfer Aluminum 40 w/valve, Brushed No-Coat In Stock $169.00

I've purchased eight tanks from these guys/gals.

Also available at:

Dive Right In Scuba

Another good retailer.

 

[Cave Diver]

The other question seems to be where to get Luxfer 40s? Research here indicates that Catalina cylinders have absolutely terrible buoyancy, while Luxfers were handed down from The Almighty himself.

However, I cannot find Luxfers available ANYWHERE. I work in a shop and can get Catalinas all day long, but apparently they are to be avoided like the plague.

Is it REALLY that bad, or is it overstated? Would Catalina 40s work OK as deco bottles?

I have both Catalina and Luxfer 80's that I sling for various reasons. I HATE the way the Catalinas trim out, and whenever possible I will use those as bottles I drop, not carry.

All of my 40's are Luxfer so I can't compare those head to head.

 

[50Fathom]

I have both Catalina and Luxfer 80's that I sling for various reasons. I HATE the way the Catalinas trim out, and whenever possible I will use those as bottles I drop, not carry.

All of my 40's are Luxfer so I can't compare those head to head.

I've heard the same about the Catalina and Luxfer 80s.

Anyone know if the 40s ride similar or different?

This chart indicates similar measurements for the outside and similar weight, but radically different buoyancy from the two manufacturers.

Scuba Cylinder Specification Chart from Huron Scuba, Ann Arbor Michigan