Is there a new tank close to the old steel 72 in buoyancy shifts and weight?

[danvolker]

Dan,

Come back up here to Buffalo. Dry suit, big doubles, stage/pony, reels, lights, etc. You will forget about all that "silliness"...

I may have mentioned to you before, I was certified by Great Lakes divers ..in Buffalo
So I do have memories of diving under the ice, and all the canon balls and old relics along the Niagara river. I did enjoy diving there....but, I enjoy it "more" here in South Florida, or the Bahamas, or Tobago, or Belize, or Fji, all a bunch of places with significantly warmer water

Now when you come down here to Palm Beach, to dive with my buddies and I, I'm pretty sure you'll like all the silliness we specialize in

---------- Post added March 5th, 2015 at 09:07 PM ----------

The only doubles i ever used were double 70's. I think a big fat steel tank is easier to handle and lighter. As for the buoyancy shift, that is entirely a function of the tank volume/capacity not the composition of the tank - but i suppose you know that.

Consider the surface area of two tanks versus a fat one, the drag has to be greater with doubles.

Also, nobody local will fill those tanks will they? I have a few, they were the PERFECT tank for my wife years ago. She could dive longer on one, than I could on a 100 cu-ft aluminum tank.

You mean fill the steel 72's? I bet Wet Pleasures would.....???

 

[BRT]

Dan, I think there are lots of steel 72's out here on the West coast. I shipped my last 6 off to somebody for a little more than it cost to ship them because I was tired of looking at them. I don't think they will fail hydro unless visually because of rust but the worst of mine had small rust spots, nothing I would worry about.

Here are some Ebay item numbers. Usually there are more but people can't get enough money out of them to pay to ship them.

111611370425, 171656441378

 

[danvolker]

Dan, are you concerned about buoyancy SHIFT or buoyancy itself..ie how much extra weight you need with an AL80 compared to a S72. If it's buoyancy shift then you are only talking about roughly half a pound more, no where near enough to worry about or if you want to be closer the neutral just add another 1/4 lb of weight- I use fishing sinkers, besides you get a little more gas.
I dive no BC with AL80s all the time, matter of fact, I don't like 72s in warm fresh water because they overweight me, with AL80 I am dead on neutral with no additional weight (but usually a DH reg)

I could use an al 80 and make it work.,....but I used the steel 72's for a very long time in the 70's and 80's, and always thought them a superior tank to the Al80.....and of course, when I went deep, they got cave fills.....
I only dive salt water, so the fresh water issue is not a factor.....Have not been to the caves in North florida for almost a decade now.....not enough fish to shoot video of in the caves

---------- Post added March 5th, 2015 at 09:18 PM ----------

Wow, the scooter can change the whole picture. Now you are balancing drag, battery capacity, and range. A scooter will definitely give you better panoramic videos than a mono-fin. Add enough battery and you can drive a VW buss through the water… sideways.

Is this a simple video survey or will you want to stop and look at stuff? You can pretty well kiss minimal hydrodynamics goodbye lugging a 5D in a housing around. GoPros are another story.

My gut says saddle mounting two cylinders around the body of the scooter will handle better than one in front.

I dive a lot...in lots of different environments...and see my dive gear somewhat like clubs in a golf bag.... If I am on one of the deep reefs off Juno or Jupiter, I am on the Gavin scooter, and maybe using an hp120 for the 90 to 110 foot or deeper dive.

If I am on one of the shallower reefs off of Boynton, I would like to lose all the weight and hassle of the heavy scooter and big tank, and be more like a freediver....but, I still want to be able to shoot video...sometimes maybe with a go pro and really slick, sometimes with my Canon in the Aquatica housing....and that means I am not going to be all that slick no matter what....What I want to use, will depend on the "mission" of the day

This whole no wing and ultra streamlined thing, will be in places I won't want to bring the scooter.

Here are 2 videos to show you the kind of stuff I like to shoot...and the way I like to dive..I do like to move a lot...and swim....

[video=youtube_share;PIaXVw61qJI]http://youtu.be/PIaXVw61qJI[/video]

[video=youtube_share;ZTdpxYSiv5M]http://youtu.be/ZTdpxYSiv5M[/video]

 

[Bob DBF]

Try to find a Faber steel Mid pressure (3000+10%) it's buoyancy is about 3# heavier empty than a old '72, but a lot smaller tank. I loved using them for quick or shallow dives, but I need a wetsuit so the weight wasn't a problem. As for j-valves, you should find them lying about in piles, if not PM me, I just recycled a few old AL 80's.


Bob

 

[Rich Keller]

You shouldn't have any trouble finding old steel 72s. And concern about the fatigue level is exactly what hydro testing is for. I'd be more concerned about whether they are lined or not. That can prevent a clean bill of health on VIP.

The lined tanks a great as long as the lining is PERFECT. Once you get one problem spot, no matter how small you will need to have it tumbled. The current statistics on 72s do not match the original 72s though so you can not go by that. I can tell you that once you get down to 500psi they almost float but not with a J valve. You need the valve that per-dated the J valve. This will not save you much on drag and the original nut holding the burst disk usually needs to be updated but it will get you to the weight that you are looking for.

 

[Eric Sedletzky]

Try to find a Faber steel Mid pressure (3000+10%) it's buoyancy is about 3# heavier empty than a old '72, but a lot smaller tank. I loved using them for quick or shallow dives, but I need a wetsuit so the weight wasn't a problem. As for j-valves, you should find them lying about in piles, if not PM me, I just recycled a few old AL 80's.


Bob

I could probably get boxes of J valves from Ron Hunt too since they changed all of them out on all the tanks at SSU

 

[halocline]

The closest tank on paper is the LP85, still a 7" tank, still more-or-less neutral when empty. But, they are much heavier on land, and overall bigger tanks with more mass and that affects how they feel in the water. I do a lot of local dives with 72s, they're my favorite, and the closest thing I have used that sort of feels the same is an AL63. They're fairly lightweight and compact; I think they're a couple of pounds positive empty but so are some 72s if you actually measure them. I tossed a couple of mine empty in the tub and they floated.

I had a pair of my 72s doubled for a long time; I thought they'd make excellent small doubles but it turned out that, at least to me, double AL80s are a lot nicer in the water. It doesn't make sense, but that was my experience. The 72s are far better as single tanks. And the real beauty is they only weigh 26lbs on land. For us lazy folk that's great for shore dives.

So I would suggest looking for a couple of 72s in good shape, PST if you can find them, because the PST REE number is widely available and as such you can hunt around for a hydro shop to give them the plus rating. Otherwise you're only getting 65cft. If you have any trouble finding the 72s you want, maybe try a dive or two in your new minimal set up with an AL63 and see how you like that. I FAR prefer them to AL80s, but that's just my opinion.

 

[Akimbo]

I gave this some thought last night. The height of the tank could be a much bigger issue using a monofin. You will get really tired of having a tank slap you in the butt on every up-kick. That might be an argument for a short fat single or short small diameter doubles. It might be prudent to get the fin first and experiment with tanks on hand before taking the next step.

 

[Bob DBF]

I gave this some thought last night. The height of the tank could be a much bigger issue using a monofin. You will get really tired of having a tank slap you in the butt on every up-kick. That might be an argument for a short fat single or short small diameter doubles. It might be prudent to get the fin first and experiment with tanks on hand before taking the next step.

That is why I brought up the Faber 72

Faber 72 3000+10% 72 cuft 6.75 dia 20.5 length 28.7# empty -3.7 buoyancy empty -8.45 buoyancy full

The issue is if you have the # to drop from your belt, it would dependent on your biopreme and wetsuit.




Bob
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There are more ways than one to skin a cat, however the cat never likes it.

 

[rhwestfall]

Is that Faber 72 @ 3000 or at 3300? I have one from back in the mid 90's when they were branded for ScubaPro. We loved those tanks..... I could dive a 1/4" farmer john and a jacket (so 1/2" on my core) with no weight belt....