Source for lead weights - 2.5lbs

[FIXXERVI6]

Does anyone know where I can get my hands on 2.5lbs lead weights, the hard type that slides onto the belt? I've never seen them before but I figured I would ask before I took a hack saw to my 3 pounders

 

[psiborg1812]

I don't know id 2.5 pounders are made or not. However, if you have spare lead lying around, you can always mold your own!

Trident Systems Lead Weight Mold Scuba Diving Gear Weights and Belts: Compare Prices, View Price History and Read Reviews at NexTag

Just don't pour enough lead for 4.5 lbs and you'll be good!

 

[ZzzKing]

What are you using them for where 1/2# is critical? Not criticizing, just asking.

 

[FIXXERVI6]

What are you using them for where 1/2# is critical? Not criticizing, just asking.

8lbs of lift with double aluminums and 5/7 suit, not a lot of room for error, currently using 6lbs would like to use 5lbs

 

[richerso]

Wow! Maybe our hobby is progressing into a position where, at some time in the future, we can all debate the merits of adding 2 ounces of lead or removing 1 ounce. How cool would that be? I am getting bored with the debates over split fins or blades. Seriously. Serious academic comment here. Not criticizing (just in case it sounds that way). I really am impressed.

 

[FIXXERVI6]

With only 8lbs of lift there is not a lot of room for error, currently with full tanks I can not float with my head out of the water with two full 80's, when they are breathed down I can float with my head out of the water.

One may say the obvious fix is add more lift for more margin and don't worry about the the pound of lead.

That affects bouancy control - example

Nomad approx 25 liters of capacity, let's say with 108's @ 3600 we are running half full, 12.5 liters approx 27 lbs of lift, this is realistic considering 108's @ 3600 are around -11 each, if you drop in the water column 33 feet your bladder goes from 27lbs of lift to approx 13.5lbs of lift, that is a 13.5lbs shift (approx), males can swap out on average 4.6 liters of gas with our lungs (Wikipedia) and I note the breath not the total lung capacity as it is impossible to breath all air out - about 10lbs of lift, that means you're going to be a rock you will have to add gas to your bladder even with full breath you are going to sink with a 13.5lbs shift in lift.

In steps mini bcd 8lbs of lift if you're running 3/4 full and you have 3 liters in, that’s about 6lbs of lift approx, now drop 33 feet you now have 3lbs of lift, that means you have to make up 3lbs of lift with your lungs if you do not add air to your BCD - can you do it? You betcha. The more lift your BCD has and the more weight you have to lift with it, the more you have to mess with the inflator.

The closer to neutral I can get the entire rig the bigger the shift in depth I can handle without having to add/remove gas from the BCD.

You'll notice newer divers with 20lbs of lead will tend to show an increase in bouacy control when you get them properly weighted.

If I could sit down with the equipment and a calculator to come up with the exact amount of weight I need to the ounce, I would do it, but there are too many factors that come into play to be able to do that, so to the pound will make me happy.

Currently with 6lbs of lead and a 5/7 wetsuit, two aluminum 80's with no plate or manifold I can hover in 10 feet of water with 500 psi in each cylinder and there is still a little gas left in my BCD, I'll be satisfied when I can do that with 350psi in each cylinder and no gas whatsoever in my BCD.

 

[psiborg1812]

With only 8lbs of lift there is not a lot of room for error, currently with full tanks I can not float with my head out of the water with two full 80's, when they are breathed down I can float with my head out of the water.

One may say the obvious fix is add more lift for more margin and don't worry about the the pound of lead.

That affects bouancy control - example

Nomad approx 25 liters of capacity, let's say with 108's @ 3600 we are running half full, 12.5 liters approx 27 lbs of lift, this is realistic considering 108's @ 3600 are around -11 each, if you drop in the water column 33 feet your bladder goes from 27lbs of lift to approx 13.5lbs of lift, that is a 13.5lbs shift (approx), males can swap out on average 4.6 liters of gas with our lungs (Wikipedia) and I note the breath not the total lung capacity as it is impossible to breath all air out - about 10lbs of lift, that means you're going to be a rock you will have to add gas to your bladder even with full breath you are going to sink with a 13.5lbs shift in lift.

In steps mini bcd 8lbs of lift if you're running 3/4 full and you have 3 liters in, that’s about 6lbs of lift approx, now drop 33 feet you now have 3lbs of lift, that means you have to make up 3lbs of lift with your lungs if you do not add air to your BCD - can you do it? You betcha. The more lift your BCD has and the more weight you have to lift with it, the more you have to mess with the inflator.

The closer to neutral I can get the entire rig the bigger the shift in depth I can handle without having to add/remove gas from the BCD.

You'll notice newer divers with 20lbs of lead will tend to show an increase in bouacy control when you get them properly weighted.

If I could sit down with the equipment and a calculator to come up with the exact amount of weight I need to the ounce, I would do it, but there are too many factors that come into play to be able to do that, so to the pound will make me happy.

Currently with 6lbs of lead and a 5/7 wetsuit, two aluminum 80's with no plate or manifold I can hover in 10 feet of water with 500 psi in each cylinder and there is still a little gas left in my BCD, I'll be satisfied when I can do that with 350psi in each cylinder and no gas whatsoever in my BCD.

Average lung total capacity is 5-6 liters, with resting tidal volume ( a normal breath) being around .5 liters. Total exhalation or inhalation from a normal breath is around 2 liters. So, if you exhale reeeealy hard and then inhale reeeeally hard, then you'll probably move 4.5 liters of air.

Not trying to nitpick, just wanted to make sure you had more than enough information! And megaditto on the improvement in buoyancy after being properly weighted! One of the things we like to have our OW students try out is to get neutral at the start of the dive and then see who can touch their inflator valve the least! It really makes them focus of their breathing, rather than their BC, to control buoyancy.

Edit: is lead soft enough for you to be able to just hacksaw off pieces from a 3 pounder till it gets to the desired weight? Maybe it would be possible to cut open a soft weight and take out the shot till it gets light enough also...

 

[sean_nc]

Does anyone know where I can get my hands on 2.5lbs lead weights, the hard type that slides onto the belt? I've never seen them before but I figured I would ask before I took a hack saw to my 3 pounders

They do make 8oz weights for fishing. You could keep the 2 lb. weights and add a couple of fishing weights.

... you must be way more fine tuned than most people. I've still got a long way to go.

 

[FIXXERVI6]

even if I'm way off (probably am) and the lung volume swing is 2 liters thats ~4.4lbs of lift, still enough to offset the 3lbs swing in my example

I thread the weight directly to the rig - it is not ditchable so softweights are not an option for me.

These guys have 2.5 pounders listed
Purity Casting Alloys - Scuba Dive Weights

 

[FIXXERVI6]

They do make 8oz weights for fishing. You could keep the 2 lb. weights and add a couple of fishing weights.

... you must be way more fine tuned than most people. I've still got a long way to go.

Normally I wouldn't bother with a pound, but with only 8lbs of lift... I want it as close as I can get it!