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Aldora tank buoyancy

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tbone1004

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the problem right now is you need to know the brand of tanks they're using. The odds of them using actual HP120's is pretty slim because that would require everyone have DIN valves per regulations, that is why they have skinny necks and the reason the tanks are now rated at 3442 psi with normal valves.

The fun part comes when you have to find out what brand they are using.

Scuba.com has a lot of their information wrong just from what you posted.
no AL80's go from -1.8 to 2.6lbs, they can't, that's just only 50cf of gas.
The AL63's from Luxfer are 2.6lbs positive when empty, but are 2.1lbs empty
Normal Al80's are 1.8 or 1.4lbs negative when full to 4 or 4.4lbs positive when empty. Those are Catalina and Luxfer respectively.

Same goes for steel tanks. If they are using true PST HP120's, then they are 10.3lbs negative full and 1.3lbs negative when empty, but if they are the newer PST E7-120's, then they are -10.5 to 0. If they're using Worthington E7-120's, then they are -11 to -2. If they are Faber F7-120's, then they are -8.8 to +0.7.

So, unfortunately there is literally 0 way to know other than getting the exact tank specs from them. Also, your last statement couldn't be farther from the truth, most steel tanks have somewhat comparable empty buoyancy specs across the manufacturer, so the logic of dropping more weight for larger tanks doesn't work. From PST on the true HP cylinders the opposite is actually true. The HP120's and HP100's are -1.3 when empty, but the HP80 from the same series is -3.3, so with the smaller tank you actually use 2lbs less weight and you can go between the HP100 and HP120 without changing a thing.

This site has the vast majority of tanks on the market.
Scuba Cylinder Specifications from Tech Diving Limited - 928-855-9400
 
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ronscuba

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Sounds like I'll have to offset around 8-10 lbs. I have a 5mm but I think that will be way too much for April. I guessing April water temps will 79-80. Maybe my core warmer and vest would work.
 

DandyDon

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cpichette

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I was just down diving with Aldora last week and used their new tanks. They are steel 120's, but are, i think, a couple pounds less heavy than their old steel 120's. I don't wear a wetsuit or weight with either the old or new tanks. They are a bit bulky and require some shoulder strength to control. They are more bouyant when you are positioned vertically rather than horizontally. I like them, but they take some getting used to compared to aluminum 80's.
 

boulderjohn

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the problem right now is you need to know the brand of tanks they're using. The odds of them using actual HP120's is pretty slim because that would require everyone have DIN valves per regulations, that is why they have skinny necks and the reason the tanks are now rated at 3442 psi with normal valves.

Why are you guessing like this? This is a big operation that has served many thousands of divers over the years. I have used them many times. They primarily use HP 120s, unless they have made a sudden unannounced change. They put doughnut adapters in so that people with yoke regulators can use them.
 

DjDiverDan

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It's been probably 5 years since I dove with Aldora - although they are my first choice Op, all my trips in the recent past have been group trips in which I dove with the Dive Op selected by the group, usually Dive with Martin. But when I did dive with Aldora, I brought my own DIN Adaptor and switched out the Yoke for the DIN on my first stage. For most divers who didn't have a DIN Adaptor, Aldora provided one. It's my understanding that almost all Yokes of recent vintage (less than 5-7 years old?) are capable of handling the higher operating pressure of HP tanks - 3500 psi vs 3000 for AL (3200 for some AL 100s), but since the tank valves are set up for DIN connectors, you need a DIN Adaptor. Frankly, I prefer the DIN connection - none of those little leaks from old O-rings that leave a trail of little tiny bubbles from the tank valve.
 

Dave Dillehay

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At Aldora we have both Worthington and Faber HP tanks, in 80cf, 100cf, and 120cf. Worthington stopped making tanks last year thus we have gone to Faber for recent purchases. All have valves that are convertible from DIN to yoke and it is now rare for us to change out the regulator inlet fittings for our customers (that was the case 20 years ago when the HP tanks were only available in DIN) although we still have DIN adapters for almost all regs.

As to capacities and buoyancy characteristics, the difference between the various HP tanks are so small as to be of little significance for most divers. With all of our HP tanks, a rule of thumb is to drop 4 lbs of lead compared to an aluminum 80. As you may have noted from earlier discussion, the HP tanks have exactly the right kind of buoyancy to get you down quickly and yet not bob to the surface at the safety stop. To me that is nearly as important as having 25-50% more air molecules!


Dave Dillehay
Aldora Divers

PS We have never used Alum 100s which have VERY poor buoyancy characteristics.


Bienvenidos - Aldora Divers | Only the best of Cozumel
 

scubafanatic

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At Aldora we have both Worthington and Faber HP tanks, in 80cf, 100cf, and 120cf. Worthington stopped making tanks last year thus we have gone to Faber for recent purchases. All have valves that are convertible from DIN to yoke and it is now rare for us to change out the regulator inlet fittings for our customers (that was the case 20 years ago when the HP tanks were only available in DIN) although we still have DIN adapters for almost all regs.

As to capacities and buoyancy characteristics, the difference between the various HP tanks are so small as to be of little significance for most divers. With all of our HP tanks, a rule of thumb is to drop 4 lbs of lead compared to an aluminum 80. As you may have noted from earlier discussion, the HP tanks have exactly the right kind of buoyancy to get you down quickly and yet not bob to the surface at the safety stop. To me that is nearly as important as having 25-50% more air molecules!


Dave Dillehay
Aldora Divers

PS We have never used Alum 100s which have VERY poor buoyancy characteristics.


Bienvenidos - Aldora Divers | Only the best of Cozumel

This tank info would make a nice addition to the FAQ's section of the aldora.com WWW site. Just sayin' :)
 
https://www.shearwater.com/products/teric/

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