Whats is the weight and bouyancy of an old steel 72?

[Benthos]

Good SAC rate so LP80 is a bit big. Trying to get smaller and lighter with out HP- my compressor only hits 3000. Anyone know about how heavy the old steel 72's where and how much they weigh empty? How +/- are they full and empty? How come no one makes LP 72 any more?

 

[donooo]

Here, try this.

http://www.huronscuba.com/equipment/scubaCylinderSpecification.html

Got two old steel 72's here I'd love to sell.

adiois don O

 

[Benthos]

Yes the huron scuba link does not have a LP steel 72 listed. None of the charts do. I think they are about -5 to neutral but what about the tank weight?

Thanks for the offer but unless they where really cheap the shipping wouldn't make it worth it.

ThX
RT

 

[donooo]

Sorry, you're right. I just knew that was a pretty complete list and didn't bother to check. So out of the PSI Cylinder Inspection book there is a steel 71, 2250 pressure.

Empty Weight 29.5
Empty Bouancy 3.5
Full Bouancy -2.0

Is that better ?

don O

 

[DA Aquamaster]

I've seen those numbers before, but they do not really match my experience with Steel 72's, and I own about 20 of them.

They vary a bit my manufacturer, but most of mine are closer to being 4 lbs negative when full to about neutral to 1 lb positive when full with the valve attached.

They do weigh in right at about 30 lbs with the valve.

 

[TSandM]

THANK YOU, DAA! I have two old steel 72s that I have been considering doubling up, and I hadn't been able to get any good data on their buoyancy. I was considering buying a fish scale. You have saved me the trouble, while simultaneously letting me know that they would NOT be good choices for doubles for me in cold water.

 

[spectrum]

I have a buddy who dives those and says they end the dive just about neutral.

Pete

 

[DA Aquamaster]

You have saved me the trouble, while simultaneously letting me know that they would NOT be good choices for doubles for me in cold water.

Bouyancy wise, they are not as good as a pair of aluminum eighties from the perspective of having more ditchable weight available. But in terms of keeping your total weight down, they are much better in that you can drop about 4 pounds of lead for each tank compared to using AL 80's - leaving you with 8 lbs less lead to carry. Given that AL 80's are also a few pounds heavier, the total weight savings in terms of what you have to carry back up the ladder is on the order of 14-15 lbs.

For a cold water diver who needs the weight anyway to get neutral with a 7mm exposure suit or dry suit, Steel 72's are a good way to go. You just need to ensure you have enough wing to get neutral at depth with the suit compressed and two nearly full tanks. You also need to ensure you can swim the load up in the event your wing fails and/or alternatively you can use a dry suit for redundant floatation, use a wing with redundant bladders, or carry a lift bag and reel to provide additional lift and support.

Personally, if you are diving doubles and getting into a deco obligation, I don't feel that ditchable weight is an attractive option at all as once you dump it and start up, you are probably going all the way to the surface. Ditchable weight and deco diving are not compatible concepts.

On the other hand, for a warm water diver, who may be diving in a very thin suit or shorty, does not need much weight and may be over weighted by steel 72's, double AL80's are clearly a better way to go.

 

[TSandM]

Al 80s were essentially never on the table for me, diving in cold water. I already carry enough weight to sink a battleship! The question was the old 72s, of which I have a pair, or buying a pair of tanks (either new 72s or something larger) specifically to double up. I don't want anything that goes positive at the end of the dive, because packing on weight to cancel that out in addition to the weight of the doubled tanks in the first place might be enough to break the camel's back.

 

[HowardE]

I've seen those numbers before, but they do not really match my experience with Steel 72's, and I own about 20 of them.

They vary a bit my manufacturer, but most of mine are closer to being 4 lbs negative when full to about neutral to 1 lb positive when full with the valve attached.

They do weigh in right at about 30 lbs with the valve.

I have 2 steel LP 72's (not doubles) - I would say mine are -1lb to neutral when closer to empty. Yeah - they weigh about 30 lbs on land.