Weighting question about steel tank vs. aluminum

[sabbath999]

I am being an idiot and I can't figure the weighting changes between steel and aluminum.

I will be diving a steel tank this weekend that has the following characteristics.

Full: buoyancy -11
Empty: buoyancy -2

At least this is according to the manufacturer.

I know what the proper amount of weight to wear with my rig for an AL80.

Is the following correct then?

Since the AL80 has a buoyancy at 500 psi of +4.4 pounds positive and the steel is -2, then I take off 6 pounds of weight?

Also, does it matter whether I am in salt or fresh when using these figures?

When I get to 500 PSI I will do a real weight check at 15-20 feet in the water, I am just trying to get ballpark.

 

[Firefyter]

Since the AL80 has a buoyancy at 500 psi of +4.4 pounds positive and the steel is -2, then I take off 6 pounds of weight?

Correct

Also, does it matter whether I am in salt or fresh when using these figures?

It doesn't matter as long as you are comparing apples to apples. In other words, if you know the weight you require with an AL80 in fresh water, you will need 6 lbs. less with the steel in the same fresh water.

If you know the weight you require with an AL80 in salt water, you will need 6 lbs. less with the steel in the same salt water.

If you know the weight required for one type of water and are going to the other, you really need to do a proper weight check. In my case, I have to add 6 lbs. when going from fresh to salt with an AL80, so I could dive the steel with no extra weight added.

 

[Belce]

The other big advantage of that steel tank is they weigh about as much as a full Al80 tank full as well and while the steel tank is actually 100, the aluminium is actually 77 and just rounded up for naming sake ease. Steel HP 100's win on so many levels compared to AL80's. So net you find yourself 5lbs lighter and with 1/3 more air, win/win.

 

[Garrobo]

What's a steel tank?

 

[orm]

What's a steel tank?

Steel is an alloy consisting mostly of iron, with a carbon content between 0.2% and 2.1% by weight, depending on the grade.

A tank is a tracked, armoured fighting vehicle designed for front-line combat which combines operational mobility and tactical offensive and defensive capabilities.

There you go.

 

[emoreira]

What's a steel tank?

Don't know if your question is serious or not, but, here is it :
XS Scuba Worthington Steel Scuba Cylinders

 

[McCainiac]

Steel is an alloy consisting mostly of iron, with a carbon content between 0.2% and 2.1% by weight, depending on the grade.

A tank is a tracked, armoured fighting vehicle designed for front-line combat which combines operational mobility and tactical offensive and defensive capabilities.

There you go.

I need that!!!

 

[Buoyant1]

What's a steel tank?

Is this like the argument "this is my rifle, this is my gun"??

I dive with steel cylinders.....

 

[fnfalman]

Is this like the argument "this is my rifle, this is my gun"??

I dive with steel cylinders.....

I dive with steel pressure vessels.