Steel Tanks: What should I know?

[Wijbrandus]

I have a steel tank I inherited from a friend of the family. It's just been sitting in my closet for the last few months because I don't get to dive like I want to here in Colorado, and when I do I rent aluminum.

I have been considering using it, but since it's only one tank, I'd have to redo my weighting between dives when I swap from steel to aluminum.

What additional concerns are there when diving steel? I've heard some people say not to dive steel tanks in 7mm wetsuits because of the compression issues, but I'm not entirely sure how much of a factor that really is.

I want to eventually use doubles and learn staged decompression, but that's quite a ways out. Is this worth keeping a hold of it until I can get another to pair up, or would I then buy a matched set of brand new tanks?

I'm remembering (and might easily be wrong) that it is a steel 72 from 1986. It is in current hydro and VIP. It was tested before I recieved it. I use a steel plate with 40# Eclipse wing, and use 24 additional pounds in cold water.

I intend to get my drysuit/nitrox certs this winter, in case that has a bearing. I do know that making the tank nitrox friendly would require a good bit of additional cost.

 

[El Orans]

I've heard some people say not to dive steel tanks in 7mm wetsuits because of the compression issues, but I'm not entirely sure how much of a factor that really is.

That's news to me. Around here almost everyone I know or have seen diving uses steel tanks and a 7mm wetsuit. Why would that be a problem?

 

[Wijbrandus]

That's news to me. Around here almost everyone I know or have seen diving uses steel tanks and a 7mm wetsuit. Why would that be a problem?

Let's just say I heard it on SB. I'll leave it at that.

To clarify, someone once said that anyone who dives a steel tank and a 7mm would die a horrible excruciating death as they sank into the abyss due to overweighting. :11:

I just thought I'd ask and get the real story.

 

[MechDiver]

That's news to me. Around here almost everyone I know or have seen diving uses steel tanks and a 7mm wetsuit. Why would that be a problem?

I believe he was actually referring to using steel doubles with wetsuits, which is frowned upon in some locations. A single steel, especially a 72 would not be a problem.

Wijbrandus,

Steel 72s are in fairly wide demand, so I would keep the tank for now. Make sure you have some pressure in it. As far as later use, a set of 72s would probably be too small to use for deco diving, but would work well as a substitute to two single alum 80s. I wouldn't switch between the stl and alum at this point, as you really gain little for the hassle.

MD

 

[FreeFloat]

The steel tank/wetsuit taboo deals primarily with steel doubles.

I own two single tanks myself - one aluminum, one steel. YMMV but I found my weighting to be exactly 4 lbs different between tanks. I wear a 2pc 7mm wetsuit and steel 6lb backplate; with the steel I need 6lbs of lead on the belt, and with the AL I need 10.

I did my DIR-F in the steel tank and wetsuit and never heard a word about it.

The most important consideration is to be able to comfortably and under control, swim your rig up from depth with a completely deflated wing or BC. If you can confidently do that, nobody can question your selection of tank.

 

[El Orans]

I dive with 10L and 12L steel tanks and a 7mm wetsuit. Weight varies between 4 and 6 kilos depending on type of water, weight of tank.

 

[Don Burke]

I have a steel tank I inherited from a friend of the family. It's just been sitting in my closet for the last few months because I don't get to dive like I want to here in Colorado, and when I do I rent aluminum.

I have been considering using it, but since it's only one tank, I'd have to redo my weighting between dives when I swap from steel to aluminum.

What additional concerns are there when diving steel? I've heard some people say not to dive steel tanks in 7mm wetsuits because of the compression issues, but I'm not entirely sure how much of a factor that really is.

That is only an issue if you find yourself too heavy at depth to recover from a catastrophic BC failure. The next time you are diving with an aluminum 80, flatten your BC as soon as you get to the bottom and see if you can swim the entire rig up. If you can, no problem. If you can not, you still may be good to go.

I want to eventually use doubles and learn staged decompression, but that's quite a ways out. Is this worth keeping a hold of it until I can get another to pair up, or would I then buy a matched set of brand new tanks?

I would hang onto it. If you do not get a match, it will make a pretty good surface O2 or hang tank. A single 72 is also a pretty good thing to have for short dives in very cold water.

I'm remembering (and might easily be wrong) that it is a steel 72 from 1986. It is in current hydro and VIP. It was tested before I recieved it. I use a steel plate with 40# Eclipse wing, and use 24 additional pounds in cold water.

You have the six pounds or so to give up, so I am not worred about your weighting. My only concern is if you have enough ditchable weight after taking off the six pounds. I am pretty sure you will.

I intend to get my drysuit/nitrox certs this winter, in case that has a bearing. I do know that making the tank nitrox friendly would require a good bit of additional cost.

I would not go the nitrox route for a single 72 to be used for back gas. For doubles, a hang tank, or surface O2 bottle, we are having a different discussion.

 

[rjchandler]

using the steel will save on rentals? do you normally rent two at a time.
the steel only has 63 (65) cu ft. of gas - is that enough for the dives you do?

 

[Wijbrandus]

Thanks a lot for all the replies. You certainly clarified a few things.

I didn't realize the distinction on steel was for doubles. Makes more sense that way.

I am storing the tank at 200 psi.

Unfortunately, if I were to use this tank, with my current air consumption, it would make for short dives. So the idea of using it for a stage bottle sounds really good to me.

The difference between renting a tank and filling a tank here is pretty negligible. It's just easier for me to rent aluminum rather than worry about hauling around an oddball tank to get filled, and still pick up another AL80. I prefer to make two dives instead of just one, and I can easily suck down my air within my NDL times, so two dives on a single tank just isn't in my plan. I stay down to the limit of my cold tolerance or my air. Usually the air runs out first. I suck.

I really appreciate the input. I'll leave it socked away for now, and just enjoy the rental 80s.

Don, if I go to doubled aluminum down the road, you seemed to imply this tank would be worth the expense of making nitrox friendly for a hang tank. Am I understanding that right?

Thanks again, everyone. Always do appreciate the fast and friendly info from this board.

 

[Don Burke]

Don, if I go to doubled aluminum down the road, you seemed to imply this tank would be worth the expense of making nitrox friendly for a hang tank. Am I understanding that right?

Actually, a hanging deco bottle would be a better description. Since it needs to be negative anyway, steel works out pretty well. Oxygen or EAN50 was what I had in mind.

I have never tried steel for a stage. It would seem to be too negative.