Why Aluminum ?

[Akimbo]

By 1973, the US Divers catalog listed the 3000 PSI Aluminum 80 at around $150 compared to a steel 72 at $115. They did have a single owner lifetime warranty on the Aluminum. This was in the time frame where annual VIPs were being required by a lot of dive shops due to a few problems with steel cylinders.

 

[Paladin]

Isn't it interesting that you can still buy an aluminum tank for around $150?

 

[captain]

Isn't it interesting that you can still buy an aluminum tank for around $150?

Economies of scale and modern manufacturing methods.

 

[joel smith]

I am a new diver , I had a friend that got me started into diving give me an al 80. It was nice until I started my aow classs. Then I was introduced to the Worthington 100 steel. I have another one on order and wish I never had to use an al tank again. The weight, bouancy,more air, and nitrox makes these tanks worth the money, they are pricy 360.00 , compared to al.

 

[elmer fudd]

Isn't it interesting that you can still buy an aluminum tank for around $150?

And you can get the used ones for next to nothing. There was a guy on Craigslist here in the Seattle area trying to sell 4 of them for $40, (all 4 for $40), a couple weeks ago. He even claimed 2 were in new condition. I didn't bother responding though because after you figured in the cost of hydro and eddy tests I'd be at nearly the cost of buying used LP72's and IMO, the LP72 is hands down the better tank.

 

[John C. Ratliff]

What no one has said here is that those USD steel 72 tanks came in a variety of exterior finishes. They sold some with a yellow or black Tuff-Koate exterior without a galvanizing dip under it. That led to some horrendous corrosion problems under that coating that was hard to detect. It also led to steel tanks falling out of favor, and contributed to the turn to aluminum tanks, which they stated had no corrosion problems. I saw this with some of these steel double 72 tanks that we had in the US Air Force.

Some of the newer divers are saying how great the steel 100 cubic foot tanks are, with the added 10 pounds of negative weight; I would rather dive the 72s with nearly neutral buoyancy. I have seen student become completely dependent upon their BCs for "lift" in pool sessions where they had no exposure suit on. It can lead to BC dependence, and not learning the skills of buoyancy control from the beginning.

By the way, I have just decommissioned most of my aluminum tanks, which are around 35 years old now. They will be used for display only, as they were made with the special permit and can be subject to sustained-load cracking. I am keeping my AL UDS-1 tanks, and am getting those hydroed right now; they have never been subjected to sustained loads.

SeaRat

 

[elan]

Yeah you cannot dive HP100 in fresh water with thin protection. I sometimes dive Faber LP66 (-1.5 negatove) with RAM in a pool with no BCD in a backpack in a 3 mil and I'm marginally overweight - newtral at rougly 80% of the lungs.

But when you dive a dry suit they are great. I think in salt water they are nice too. I had to use 14lb of lead with all tank last time I dove in the same suit + a hood. The BC although had some fluf but likely not more than 3-4lb. So with an HP100 I would need about 4-5 lb. With an AL backplate it's getting close to be balanced ideally.


My friend got his LP72 with yellow coating - he stripped it off and painted. Were those yellow tanks coming with the epoxy finish in the interior ?

I love my set of 72s, I dive it in a HOG setup and it's awesome for boats, If I need extra gas I just add a stage. Arguably the best tank for rec diving as doubles. I would put them on par with modern Faber LP85 which is a bit heavier yet similar buoyancy and more gas. Given we do not have hassles with + ratings here in Canada you can fill it up to the full capacity and many shops even pump them to 3000.

 

[elan]

I am a new diver , I had a friend that got me started into diving give me an al 80. It was nice until I started my aow classs. Then I was introduced to the Worthington 100 steel. I have another one on order and wish I never had to use an al tank again. The weight, bouancy,more air, and nitrox makes these tanks worth the money, they are pricy 360.00 , compared to al.

This turns a bit off topic, but never say never Each tank is good for some situation. AL80 is a perfect stage tank. It is also great as a double tank especially for tall people if you need a double tank for fresh warm water.

I was under same impression when I bought my HP100 when I started diving. Now I have 5 AL80 tanks and no HP100s (I sold them) because I have found that HP100 is one of the worst tanks for ME. For my diving personally it has no advantage other than dry weight

 

[Gilldiver]

The larger steel do buy you less weight ballast in colder waters, but if I’m down in the warm water from Hattaras south I am more likely to be in a shorty or even a T-shirt and painters paints al la Robert Shaw in the Deep. All I will need is maybe a 4# weight to be just right. So an Aluminum 80 is favored.

Up north, it is a different story.

I’ll give you a bit of history on Al 80’s and NITROX in the Caribbean, Back in the early to mid 90’s when NITROX was being introduced the Caribbean dive associations tried very hard to have NITROX banned. The way I had it explained to me by the then editor of SKIN DIVER, he lived near me and I used to see him at a club meeting now and then. Was that the dive resorts were worried that with the longer bottom times, divers would go to longer bottom time s and their boats wouldn’t make it back in time to do 3 dives per day. SO, as the largest advertisers in SKIN DIVER, SKIN DIVER was against NITROX. I’m sure someone can come up with the editorials on NITROX from 92 or 93 that were published.

This all changed when the resorts figured out that an 80 only had 80 cubic feet of air or NITROX and that 90% of vacation divers couldn’t make an 80 stretch longer on NITROX vs. AIR. So, it didn’t matter what was in the tank, the dives were the same length. But, some divers would pay” extra” for the NITROX and some divers would pay for an “extra” for a 3rd dive in the day as they didn’t have as much nitrogen built up and some might even pay “extra” for a 4th night dive.

YMMV

 

[elan]

Thats a nice piece of history thanks Gilldiver