Why are you wanting to be able to swim up a steel tank?
If you're worried about BC failure, the much easier solution would be to just carry a lift bag with you or always dive with a buddy.
The whole point of the BC is to keep you neutral when you're negative. If it fails, and you have nothing you can ditch you need to come up with a 2nd source of lift. Either a BC with dual redundant bladders, or a lift bag, or grab onto your buddy and do a controlled ascent.
In one of my cave classes, we had to "retrieve our unconscious instructor" from the bottom of a spring. While this may not sound like much of an issue, she had dual steel LP108's and a stage bottle on. I had dual steel LP85's on I could not lift her at ALL with just my own BC. My buddy came over to assist and we finally got her top side.
When we surfaced, she said we could have done one of two things:
1 - used HER BC for inflation, as it was more important to get her out of the water than let her drown, if she got away from us due to being too positive, it was better to deal with an embolism or DCS than to be dead.
2 - Drop her tanks and put her on my back gas.
Reason for mentioning this is... unless you're diving solo. this is what a buddy is there for. If your BC fails, and all your weight is on your BC/Tank (you have nothing to drop then you should be able to grab a hold of your buddy and the two of you ascend using his BC, or absolute worst case, get on his octo and drop all your gear.
I have to say when I'm diving doubles, I can in no way swim that amount of weight up. But I have a buddy or a lift bag to assist should I need it.
---------- Post added September 12th, 2013 at 09:00 AM ----------
Yes, if I had it to do over again I probably would have gotten a different. Tank, still might, but these steel tanks are costly and I already laid down the money.
Good thought though. Actually you are the first to confirm my guess that steel tanks and wetsuits are not the best fit for each other, thanks for that.
Too bad some of us learn after the $ is spent.
Steel tanks are perfect for wetsuits IMO. You just have to get used to their extra weight characteristics.
Myself and all my buddies (all cave, tech, etc) prefer steel to aluminum any day. We all dive in various thickness wetsuits, some in drysuits.
My first tank I bought a few dives after OW was a steel LP108. I dove the heck out of it. Never once having any issues with any kind of buoyancy, trim, etc.
You just need more time in the water, more practice. Your profile says you have less than 50dives... just spend more time with your gear, your tank, etc. Spend a LOT of time (or a dive or two) in very shallow water...im talking 10-20ft. Spent time traveling between those depths, hitting that magical 15ft make of "impossible buoyancy" many people have a hard time with. This will help make you a rock solid diver. Plus at that depth, a 100CuFt tank should last you a LONNNGGG time.
Don't write that tank off yet... any good diver should be able to dive with ANY tank and not have it effect his trim or buoyancy. It just takes practice to get it right. Don't be discouraged
any tank is not a wasted purchase..it just becomes another part of your stable later on