"Neutral-Buoyancy" aluminum tanks, anybody tried them? Comments, likes or dislikes?

[Leon7997]

thinking about buying one, but my LDS owner said he has not heard anything about how people like or hate them ... one online dive equipment vendor who aims for the experienced diver market said they'd heard negative comments about their trim, but when i asked for more details they stopped answering my emails ... so I'll try here to get some feedback and insight ... I like the idea of less weight in the BC pockets to start with and not having to worry about being positive with a deflated BC at safety stop time with 500psi remaining, but not sure I want to spend the $ and end up wishing I had bought something else

 

[redacted]

I achieve neutral buoyancy on all of my aluminum tanks with 4 lb of lead placed on the tanks where I want it to maintain trim.

 

[ajtoady]

I'd have to do some research , but neutral- buoyancy? Just using 2000 lbs of air makes a difference. Buy steel and shed the weight anyways.

 

[ajduplessis]

In the end it's all about your own personal preferences. Every diver is unique with different backgrounds, teachings and equipment. I don't like Ali as backgas options but would use nothing else than Luxfer Ali as stages/deco cylinders.

Steel just works better for me and I don't need to worry about buoyancy issues as my pressure drops.

I am not aware of neutral buoyant ali's, first for me but then again steel is what most people use around here.

 

[ajduplessis]

My apology, it seem like Worthington claims to make neutral to slightly negative Ali cylinders. I cant comment but would think that they would behave similar to steels.

They would also be heavy?!!????

 

[aquaregia]

I've done many dives on Luxfer AL80N tanks, which are neutral when empty. They are 77cf at 3300psi, at 3000psi they're only 70cf.

- Many LDSs won't realize that they're 3300s because they look just like the 3000psi counterpart. In that case, you're getting a good deal less air.
- Most of the weight feels to be in the tail, compared to the Luxfer AL80, so the weight will sit in a similar position to your weight belt.
- They're awful slung, so if you're on the "AL80s now which become stages when I buy steel" plan, they'd be a bad bet.

 

[eelnoraa]

thinking about buying one, but my LDS owner said he has not heard anything about how people like or hate them ... one online dive equipment vendor who aims for the experienced diver market said they'd heard negative comments about their trim, but when i asked for more details they stopped answering my emails ... so I'll try here to get some feedback and insight ... I like the idea of less weight in the BC pockets to start with and not having to worry about being positive with a deflated BC at safety stop time with 500psi remaining, but not sure I want to spend the $ and end up wishing I had bought something else

This is because you are under weighted, NOT because of AL80 is +4lb empty. At the beginning of the dive, you should be over weighted by the weight of the gas. So when you breath down the tank, you are neutral. This is true for both steel and AL tanks. With AL80, you just need to carry more weight to offset the inherent buoyance charasteristic.

Now, if you want to carry less overall dry weight, the key is a tank that is same weight or lighter on land, BUT less buoyanct in water. AL80N (Catalina C80, 34.6lb dry, 0lb empty) is not really your best choice because although it is neutral when empty, it is also heavier on land. S80 is 31.4lb dry, +4lb empty. Not much different than if you slap 4lb of lead on your S80. A steel tank like Faber LP85 (31lb dry, 0lb empty) saves your 4lb of lead compare to S80.

 

[aquaregia]

Faber 85s are bloody awesome tanks.

 

[Otto]

What difference does it make if the tank weighs 4lbs more or you carry 4lbs lead? It doesent unless you can offset the 4lbs wewight with other gear you were planning to take along. If you get the neutral tanks, and I own 3 of them, put a large piece of tape on them and mark them with "FILL TO 3,300lbs" to assist the fill station operator to wake up. If you think that you will move to technical diving in the near future get the standard tanks to use for stage and travel bottles, and yes Faber 85's do rock.

Dive safely

 

[Leadking]

I wouldn't recommend them. They are 3300psi and achieve nuetral thru an extra slug of aluminiun on the bottom of tha tank, at that pressure I'd buy a steel HP100