Steel LP72 2250psi tank spec

[elmer fudd]

What I like to do is top my 72's off from an HP119. Even once the pressure drops to 3000 psi or so a 119 still has plenty of air for most recreational diving.

 

[Cougar281]

They're my favorite tanks; I have a set of doubles and a single. If you can get a slight overfill, just a couple hundred PSI, they have the same capacity as an AL80, while weighing less and having less positive buoyancy. You can easily get the same air for carrying 10lbs less weight. What's not to like about them?

Well, everyone's different, but in my case, I think a steel tank would cause me problems. With all gear, 7mm wetsuit, a full AL80 and no extra weight, I sink like a brick. I have two old steel 72's that I chose not to get hydro'd and replace the valves on for this reason.

 

[captain]

Well, everyone's different, but in my case, I think a steel tank would cause me problems. With all gear, 7mm wetsuit, a full AL80 and no extra weight, I sink like a brick. I have two old steel 72's that I chose not to get hydro'd and replace the valves on for this reason.

Exactly what does no "extra" weight mean? Extra beyond what, none at all. Hard to believe you "sink like a rock" with a 7mil suit, an AL 80 and no weight at all.
Anyone ever told you to get the lead out of your a$$.

 

[Cougar281]

Exactly what does no "extra" weight mean? Extra beyond what, none at all. Hard to believe you "sink like a rock" with a 7mil suit, an AL 80 and no weight at all.
Anyone ever told you to get the lead out of your a$$.

No extra weight means no weight at all (other than the weight of the equipment). The instructor that did my pool sessions didn't know how I was able to tread water for 10 minutes.

 

[halocline]

Well, everyone's different, but in my case, I think a steel tank would cause me problems. With all gear, 7mm wetsuit, a full AL80 and no extra weight, I sink like a brick. I have two old steel 72's that I chose not to get hydro'd and replace the valves on for this reason.

What gear exactly are you talking about? Jacket BC....I have to say I'm extremely skeptical, here's why. An empty AL80 is 4 lbs positive. A 7 mil wetsuit is at least 10 lbs positive, probably closer to 20 depending on size, age, etc. Reg, fins, mask, light, maybe 5 lbs negative, probably less, you're still looking at at least 10 lbs positive buoyancy just in the gear. If you 'sink like a stone' that means you alone are significantly more than 10 lbs negative. Not that it's not theoretically possible, but after helping hundreds of students get weighted, I have never encountered anyone like that.

I realize you said "full" tank, but I'm sure you realize that you must weight yourself for a near-empty tank.

But, if it's true, consider yourself lucky!

 

[Cougar281]

What gear exactly are you talking about? Jacket BC....I have to say I'm extremely skeptical, here's why. An empty AL80 is 4 lbs positive. A 7 mil wetsuit is at least 10 lbs positive, probably closer to 20 depending on size, age, etc. Reg, fins, mask, light, maybe 5 lbs negative, probably less, you're still looking at at least 10 lbs positive buoyancy just in the gear. If you 'sink like a stone' that means you alone are significantly more than 10 lbs negative. Not that it's not theoretically possible, but after helping hundreds of students get weighted, I have never encountered anyone like that.

I realize you said "full" tank, but I'm sure you realize that you must weight yourself for a near-empty tank.

But, if it's true, consider yourself lucky!

In the pool when we where trying to get my weight right with a 5mil (wetsuits are medium, BTW), I absolutely could not float with the water at eye level with any lead in my BC (ScubaPro Weight integrated BC) and a full tank. When I let the air out of the BC, down I went, even with a deep breath held. No weight - float with the water line right where it should be. Oddly enough, I had the same issue with the 7mil at the quarry for my OW dives. Next time we get in the water we're going to try and get my weight figured out with an "empty" tank.

 

[Eric Sedletzky]

Cougar281,

So you're saying that with a full 7mm wetsuit, a conventional jacket style Padded up BC, and an aluminum tank you need no weightbelt or added weight of any kind? And you claim you are negative and sink?
Are all your bones made out of stainless steel or what?

Most of your body is water and muscle and bones are a little heavier than water by a small margin. Your body is at least 70% water which should equal the density of the water in a pool. Your muscle and bones are slightly negative but they're not going to drop like a rock. They will make their way down gracefully.
All the stuff like the suit, BC, and tank I add up at least 28 lbs. of positive stuff.

Even if you have 0% bodyfat (which is physically impossible) I find your claims very hard to believe.

 

[Cougar281]

Again, I don't know. I'm as mystified as you are. I was quite surprised when I found I could still sink when I exhaled with no lead in my BC & a full wetsuit. As I said, with the 5mil, the ONLY way I could hold my breath and not sink to the bottom with no air in my BC was with zero lead. ANY lead in the BC and down I went when I let the air out of the BC. I didn't spend as much time a the quarry with the 7mil trying different weights, but as I recall, I had a similar issue. Next time we're in a quarry we're going to spend some time getting my weight figured out with full gear and an "empty" AL80.

Maybe these posts should get split to a new thread so as to not continue derailing the OP's thread, and I can update with more info when we get to spend some time figuring my weighting out. I don't know if we're going to have an opportunity to work on my weighting on our float/dive trip this week, but if not, the latest it would be is probably when we go to Mermet for DUI Dog Days in two weeks.

Cougar281,

So you're saying that with a full 7mm wetsuit, a conventional jacket style Padded up BC, and an aluminum tank you need no weightbelt or added weight of any kind? And you claim you are negative and sink?
Are all your bones made out of stainless steel or what?

Most of your body is water and muscle and bones are a little heavier than water by a small margin. Your body is at least 70% water which should equal the density of the water in a pool. Your muscle and bones are slightly negative but they're not going to drop like a rock. They will make their way down gracefully.
All the stuff like the suit, BC, and tank I add up at least 28 lbs. of positive stuff.

Even if you have 0% bodyfat (which is physically impossible) I find your claims very hard to believe.

 

[iztok]

Where would one find bands for 72s? I am assuming manifold that I have on AL80s would work.

 

[knowone]

Yes save the thickness of the paint or other minute manufacturing processes
and a 3/4 thread.

EBay USA can be very kind.