Question Picked up a pair of Faber LP95s, do I need to tweak my weighting for buoyancy?

[jellycatsdad]

I picked up a pair of Faber LP95s over the past weekend, LDS has them for hydro/VIP and O2 cleaning since I do want the ability to switch back and forth between “regular” air and nitrox(when I get certified and do deeper dives).

From what I’ve read, the LP95s are heavier(37lbs empty and 8” in diameter) and wider than the Faber HP100/80s(33/28lbs and 7.25” in diameter) I usually dive with. The empty buoyancy of the LP95 is -1.2lb, vs -2 for the HP80/100s. I’ve recently gotten my weighting down to 18lbs in my current configuration(7mm wetsuit, 7/5mm hooded vest, saltwater). When I do get the LP95s back, do I need to change my weighting to 14lbs to accommodate for the heavier tank or keep it as-is and do a test dive in the pool and see how I trim and descend?

 

[rx7diver]

It's best to do a weight check whenever you change your gear.

rx7diver

 

[jellycatsdad]

It's best to do a weight check whenever you change your gear.

rx7diver

I’ll do that as well. Right now, I’ve mostly resolved my weighting drama and buoyancy/air use has improved. Got a good deal on these tanks, they need a little TLC(new valves and a tumble along with a visual/hydro).

 

[inquis]

I absolutely would adjust weight. Critically though, your empty buoyancies are off: single Faber HP80 = -1.7 lb, HP100 = -0.6 lb, LP95 = +1.7 lb.

For double LP95s, you would need MORE lead, all else being equal. About 7 lbs more than with HP80s and 5 lbs more than HP100s.

 

[Barefoot_Lawyer]

I would adjust weight. Critically though, your empty buoyancies are off: single Faber HP80 = -1.7 lb, HP100 = -0.6 lb, LP95 = +1.7 lb.

For double LP95s, you would need MORE lead, all else being equal. About 7 lbs more than with HP80s and 5 lbs more than HP100s.

I think that spec on the LP95 omits the valve.

SCUBA Cylinder Specifications – Huron Scuba, Snorkel & Adventure Travel Inc. PADI 5 star IDC in Ann Arbor, MI

huronscuba.com

 

[inquis]

I think that spec on the LP95 omits the valve.

I checked several other places which agree with the +1.7 lb. (TBH, I've not found the Huron list to be very accurate.)

 

[jellycatsdad]

I absolutely would adjust weight. Critically though, your empty buoyancies are off: single Faber HP80 = -1.7 lb, HP100 = -0.6 lb, LP95 = +1.7 lb.

For double LP95s, you would need MORE lead, all else being equal. About 7 lbs more than with HP80s and 5 lbs more than HP100s.

I’m diving single tank - not planning on doubles in either back mount or side mount anytime soon. I know for aluminum 80s, I needed 26lbs of lead just to be neutral.

I think that spec on the LP95 omits the valve.

SCUBA Cylinder Specifications – Huron Scuba, Snorkel & Adventure Travel Inc. PADI 5 star IDC in Ann Arbor, MI

huronscuba.com

I was going off that list as well and saw conflicting info - Faber says LP95s are positive but notes no valve. The current valves will be replaced with new Thermo pro valves to allow switching between DIN and yoke. Who do I believe?

 

[inquis]

The Huron list is from 2010. I know for a fact the incredibly common Luxfer S80 buoyancy and diameter is wrong. To know for sure, measure the buoyancies of your tanks with a luggage scale and a trash can, hot tub, or pool. (Air weighs 12.4 lb per cf, so no need to empty them. Adjust for saltwater by adding 2.4% of the dry weight to the freshwater measurement.)

Or just add 3 lbs of lead and refine at the end of an actual dive.

 

[Still Kicking]

Air weighs 12.4 lb per cf, so no need to empty them.

Wow, what gas giant are you living on? LOL

Air actually weighs about 0.08lb/cf.

 

[jellycatsdad]

The Huron list is from 2010. I know for a fact the incredibly common Luxfer S80 buoyancy and diameter is wrong. To know for sure, measure the buoyancies of your tanks with a luggage scale and a trash can, hot tub, or pool. (Air weighs 12.4 lb per cf, so no need to empty them. Adjust for saltwater by adding 2.4% of the dry weight to the freshwater measurement.)

Or just add 3 lbs of lead and refine at the end of an actual dive.

Well, I dive 17-18lbs now with HP100s. I’ll jump into a pool and see if I need to make any changes - or I can wait for my next ocean dive and see if I can get the boat to hand me extra weights.