Been out of the loop for 4 years what is the situation with Carbon Fiber Tanks?

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Robbyg

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Just a quick Bio. I have been Spearfishing since the late 70s and started diving in the mid 80's. Lots of stories in the 40 years of Snorkeling and Diving. I gave up spearfishing in the early 90s and turned to keeping reef aquariums. I stopped diving about 4 years ago but am still very active with Reef Tanks.
I have lots of diving stories from over the years and many close calls.

I am now outfitting myself for diving again and while I am not interested in actually buying a Carbon Fiber Tank, I do remember them being talked about as the replacement for Aluminum tanks and that all tanks would soon be Carbon Fiber. I see that they are still around but I am curious as to why they never dominated the market? I remember many divers saying there was no way they were going to put a 4500 PSI bomb on their backs. Did they have safety issues or was it just not something the industry could market to enough people?

Just curious about that and so many other new things I see on the market today. I am really looking hard at some of the newer dive computers, they have me drooling.

Rob
 

Marie13

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As far as I know from reading here, carbon fiber tanks are not DOT approved in the US for scuba. Apparently they're used for fire department SCBA, but not for diving.
 
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Robbyg

Robbyg

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As far as I know from reading here, carbon fiber tanks are not DOT approved in the US for scuba. Apparently they're used for fire department SCBA, but not for diving.

Thanks for the reply. That is very interesting. I always assumed they had already been used in Scuba Diving. Do you know what the issue was with the DOT approval.
 

broncobowsher

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Few unicorns around, but have not taken off.
A lot of the problem is most of the fiber wraps are not rated to be submerged in water at depth. Water getting into the fibers.
There are a few that work out. DOT certification is often a sticky point. Another down side is finite life. Roughly 15 years from the date born but could be different depending on who makes it. When the time is up, it's scrap. Not even scrap metal, just scrap. Even the bad alloy aluminum tanks have more life.
Weight is another issue, as in lack of weight. For many aluminum is too light and the choice tank is steel. If you get a lighter tank that is 5 pounds more buoyant, that typically means another 5 pounds of lead. You are not saving anything.
Higher pressures? many compressors if not most don't make that kind of pressure.
Don't forget the expense. And highly fragile as well. If that wrap is damaged, tank is scrap. Doesn't take much to damage it.

Add in the volume of the dive industry is based on "what's the cheapest way to..." and that puts the AL80 as the main tank for everyone to use.

The carbon fiber wrapped tanks are a product looking for a market. They are great as SCBA for fire fighters. More air, less weight. Government contracts that have a simple defined life span and pre-budgeted replacement schedule. That doesn't fit the dive industry.

Unless the price point comes down, I mean way down, less than an AL80 price, I don't see them being main stream. If someone makes one that has proper DOT ratings and can price it between Aluminum and Steel tanks, that is when you may see them start showing up in a more mainstream setting. A slightly more expensive cool factor. The lack of weight, the highly buoyant characteristic, is always going to be a downfall.
 
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Robbyg

Robbyg

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Few unicorns around, but have not taken off.
A lot of the problem is most of the fiber wraps are not rated to be submerged in water at depth. Water getting into the fibers.

Yes I can see water and carbon fiber as being an issue. I assume they tried adding some kind of flexible water proof layers onto the fibers? Seems like that might work but then again it adds more money to the equation.

There are a few that work out. DOT certification is often a sticky point. Another down side is finite life. Roughly 15 years from the date born but could be different depending on who makes it. When the time is up, it's scrap. Not even scrap metal, just scrap. Even the bad alloy aluminum tanks have more life.

Totally Agree.

Weight is another issue, as in lack of weight. For many aluminum is too light and the choice tank is steel. If you get a lighter tank that is 5 pounds more buoyant, that typically means another 5 pounds of lead. You are not saving anything.
I see your point on this but somehow I would prefer if the tank was lighter and I could just strap more weight onto the BCD. Although I would imagine the carbon fiber tanks are like inflated vests when they are nearly empty. It's easy to imagine that balancing the the BCD buoyancy from a full tank to an empty tank can become a lot more difficult.

Higher pressures? many compressors if not most don't make that kind of pressure.
Don't forget the expense. And highly fragile as well. If that wrap is damaged, tank is scrap. Doesn't take much to damage it.

Add in the volume of the dive industry is based on "what's the cheapest way to..." and that puts the AL80 as the main tank for everyone to use.

That is one of the main reasons I don't like carbon fiber. I have a friend who is into racing and his cars panels are all CF. The moment he gets touched by another car stuff starts peeling off and the damage from even a small impact become extensive and super expensive to fix. Years ago when this was being talked about for Scuba the only thing I could think of was how do you even trust a Hydro test on CF or Fiberglass? My experience with CF has been that it can just fail based on any kind of structural damage.

The carbon fiber wrapped tanks are a product looking for a market. They are great as SCBA for fire fighters. More air, less weight. Government contracts that have a simple defined life span and pre-budgeted replacement schedule. That doesn't fit the dive industry.

Unless the price point comes down, I mean way down, less than an AL80 price, I don't see them being main stream. If someone makes one that has proper DOT ratings and can price it between Aluminum and Steel tanks, that is when you may see them start showing up in a more mainstream setting. A slightly more expensive cool factor. The lack of weight, the highly buoyant characteristic, is always going to be a downfall.

I agree and so I assume that it's safe to say this is just never going to happen.
 

UCFKnightDiver

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Why would you want to wear more weight to counter balance a super buoyant tank? Makes no sense to me. Definitely a solution in search of a problem in my opinion.
 
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Robbyg

Robbyg

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Why would you want to wear more weight to counter balance a super buoyant tank? Makes no sense to me. Definitely a solution in search of a problem in my opinion.

Sometimes I dive off the beaten path and have to lug the gear across long paths that have no roads. It's about weight distribution for me during the walk. I am not sure how much lighter a carbon fiber tank would be, but its a lot easier to carry weight on a belt or BC versus a heavier tank on the shoulder. I am not getting any younger LOL.
 

JohnN

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I’m still unclear how the EU (which leans towards being a ‘nanny’ state) allows 300 bar tanks. One of life’s mysteries
 

Jonn

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I can’t imagine why anyone would want those big carbon balloons floating around even if they WERE practical. In other domains everything is judged on a ‘per weight’ basis, every gram of excess material is painstakingly shaved off or substituted with unobtanium to produce the leanest and meanest possible product. Scuba is the exception to that rule, especially in cold water. I don’t even like aluminum tanks: too light!
Anyone know how they’re hydro tested? The point of hydro is to stretch the metal just a little bit and observe how well it recovers. Carbon fiber is brittle though, any stretch is too much stretch for it...
 
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