Wing size for 12L steel

[moyangthered]

Hey everyone.
Just wanting to know what people's experiences are with 300 bar 12L steel cylinders and how much lift was needed for it. I've recently got some for a good price.
I currently dive an XDeep Zeos 28 steel bp and usually with a 2.8L pony. I'm thinking I may need some more lift to be safe.

Thank you!

 

[inquis]

Your wing compensates for gas weight and wetsuit compression. Gas weight is 4.2 kg, and a 7mm single-layer wetsuit might lose 4 kg. That's ~8 kg worst case, and ~4 kg on the surface. Your wing is 28 lb/12.7 kg. I personally think that is plenty of margin.

That said, the wing does need to float your rig if you remove it at the surface. If you have more than 6 kg of integrated weight, it would be a problem. That sounds like thick drysuit layer territory, and I would want some lead on a weight belt to reduce buoyancy disparity if I had to remove the rig at depth (e.g., entangled).

 

[rsingler]

^---- THIS!!
@inquis hit EVERY key point.
Even with a wetsuit, 28# lift is likely adequate, though distribution of weight will be key.
In a worst case scenario, partial weight ditching will keep you safe. I think a weight belt for part of your ballast might be critical.
But the freedom of an adequate wing that isn't so large it taco'es is fantastic. Much more streamlined.

 

[Zef]

When I lived in Europe I regularly dived with a similar setup: steel backplate, 12L steel cylinder and a slung 3L pony bottle.

I used (and still use) a Dive Rite Voyager wing. Dive Rite specs this wing as having 35lbs (15.9kg) of lift. I prefered the 35lb wing as I believe it gave me a better margin to work compared to a smaller capacity wing, and it the physical size was not considerably bigger than Dive Rites 25lb wing, so there was really no penalty for the wing with the slightly larger capacity.

As Inquis points out, whether you need more lift than your Zeos 28 offers, is dependant on all the aspects of your configuration, such as how much ballast you need/prefer and how you carry it, and any other equipment you might be carrying/attaching to your bpw, such as a camera system, etc.

-Z

 

[MarkA]

That said, the wing does need to float your rig if you remove it at the surface. If you have more than 6 kg of integrated weight, it would be a problem. That sounds like thick drysuit layer territory, and I would want some lead on a weight belt to reduce buoyancy disparity if I had to remove the rig at depth (e.g., entangled).

Compared to a 232bar cylinder. The 16.7kg 12l 300bar cylinder will use up a lot of that 6kg. So lead on a belt makes sense.

 

[BoltSnap]

Note that the 300Bar 12L specs aren't the same as the 232Bar 12L steel tank.

 

[Wallowa]

Your wing compensates for gas weight and wetsuit compression. Gas weight is 4.2 kg, and a 7mm single-layer wetsuit might lose 4 kg. That's ~8 kg worst case, and ~4 kg on the surface. Your wing is 28 lb/12.7 kg. I personally think that is plenty of margin.

That said, the wing does need to float your rig if you remove it at the surface. If you have more than 6 kg of integrated weight, it would be a problem. That sounds like thick drysuit layer territory, and I would want some lead on a weight belt to reduce buoyancy disparity if I had to remove the rig at depth (e.g., entangled).

Not certain what a single layer wet suit is, but assume that does not include my "farmer john" with a hood.....19lbs positive [7mm] plus 7mm booties/gloves at 2+ lbs.....at surface and less than 8lbs at 100 feet....do disagree with: "That said, the wing does need to float your rig if you remove it at the surface.".....if in a moment of inattention it [gear] could then sink into oblivion; needs to be able to float at the surface....perhaps I am misunderstanding what the "rig" is.....concur about a belt or at minimum weights that can be dropped; having drop weights is a no brainer for me.....having too much buoyancy for me is like having too much horsepower.....unless too bulky or constricting a few more pounds of lift might be nice at depth...rather than balancing on the head of a pin, cutting the positive buoyancy to what you calculate you might be able to swim off the bottom with, give yourself a little extra in case you are incapacitated and can't swim the guessed at weight off the bottom...

Ps....wings compensate for all added weight of gear along with gas/ +wet-dry suit...body has positive buoyancy, in my case about 3lbs+

 

[Jim Lapenta]

I always used a wing with 32lbs of lift. More than sufficient for any steel cylinder except maybe one of the old Heisers. Those things were crazy heavy. We got one at the old shop once and I tried it in the pool. Not a fan!
I tried a 23lb for a while and never really felt it was adequate as an instructor. I wanted a wing with sufficient lift to allow me to aid another diver at the surface while dumping their weights/gear if necessary.
For solo diving? Not a problem with my drysuit and up to a steel 85.
And once I did a close comparison, the profile of the 23 wasn't that much smaller than the 32. I used HOG wings after switching from Deep Sea Supply.

 

[inquis]

The 16.7kg 12l 300bar cylinder will use up a lot of that 6kg

That 6 kg was for actual lead, over and above the tank and plate. It allowed for 1.5-2 kg negative for the tank/reg and 3 kg for the SS plate.

 

[inquis]

Not certain what a single layer wet suit is, but assume that does not include my "farmer john" with a hood.....19lbs positive [7mm] plus 7mm booties/gloves at 2+ lbs.....at surface and less than 8lbs at 100 feet....

Single-layer is a normal one-piece wetsuit. (I'd term your farmer John a 2-layer.) Since we should weight for neutral near the safety stop (or slightly above), the compression that matters to the wing would be about 7 lbs (based on the difference from 15 lbs, not 21 lb). Regardless, that's less than the 4 kg I originally ballparked above.