AL100 buoyancy characteristics??

[HenrikBP]

I've booked a dive day with a North Carolina OP that rents AL100 tanks. Apparently a mix of brands, but Luxfer for sure.

I spoke to the shop on the phone and asked about buoyancy characteristics of the AL100 as compared to AL80, which is what I've rented so far, and was told that they recommend adding 3-4 lbs when diving the AL100 compared to AL80.

So I looked up Luxfer and Catalina specs: Luxfer: +3.1 lbs when empty (+1.9 on the XS Scuba site), Catalina C100: -0.4 lbs when empty.

Scuba Cylinder Specifications from Tech Diving Limited - 928-855-9400
XS Scuba Luxfer Aluminum Scuba Cylinder Specifications

AFAIK an AL80 is generally considered to be +4 lbs when empty, so I'm wondering why the shop would recommend *adding* 3-4 lbs.

Am I missing something? Different brand or models of AL100 tanks that I haven't found? Different conditions off the NC coast making more weight a good idea (I wouldn't think so)?

Thanks,

Henrik

 

[JeffG]

I use the same weight for my AL80's and AL100's. All Luxfer.


Sounds like you bumped into the standard shop monkey.

 

[Wayward Son]

I dove 100 AL Luxfers for about 4 years. Used 2 lbs less wt than a Luxfer AL80.

 

[Wayward Son]

Catalina AL100's do not have the same numbers as Luxfers do.

 

[HenrikBP]

Thanks for the confirmation guys. It didn't make sense to me, but I've still got lots to learn, so I thought I'd ask.

Catalina AL100's do not have the same numbers as Luxfers do.

The only Catalina AL100 I could find was the C100 which is a few lbs heavier when empty. Do they make a "regular" AL100?

Thanks again,

Henrik

 

[Wayward Son]

I'm only aware of one.

 

[HenrikBP]

I'm only aware of one.

Thanks for the info.

Henrik

 

[Wayward Son]

the other thing to pay attention to is the fact that they're taller than an AL80. You may have to play with the position in your BC in order to get your trim sorted out.

 

[OldNSalty]

I'm diving Wayward Son's tanks now and I found I had to drop 3 pounds and set the tank kind of high to get it to trim out like I wanted. Now its perfect. I may have been overweighted by a pound when I started so 2 would be a good place to start. I wish I had bought these sooner. They are great.

 

[deepstops]

Catalina AL100's do not have the same numbers as Luxfers do.[/QUOTE
Cat 100s behave like steels and Lux 100s are more like an AL80.


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